The enzymatic redox reactions in natural photosynthesis rely much on the participation of cofactors, with reduced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) or their oxidized form (NAD⁺/NADP⁺) as an important redox power. The photocatalytic regeneration of expensive and unstable NADH/NADPH in vitro is an important process in enzymatic reduction and has attracted much research attention. Though different types of photocatalysts have been developed for photocatalytic NADH/NADPH regeneration, the efficiency is still relatively low. To elucidate the key factors affecting the performance of photocatalytic NADH/NADPH regeneration is helpful to rationally design the photocatalyst and improve the photocatalytic efficiency. In this paper, we overview the recent progress in photocatalytic NADH/NADPH regeneration with the focus on the strategies to improve the visible light adsorption, the charge separation and migration efficiency, as well as the surface reaction, which jointly determine the overall photocatalytic regeneration efficiency. The potential development of photocatalytic NADH/NADPH regeneration and photocatalytic-enzymatic-coupling system is prospected finally.

Carbon dioxide fixation presents a potential solution for mitigating the greenhouse gas issue. During carbon dioxide fixation, C1 compound reduction requires a high energy supply. Thermodynamic calculations suggest that the energy source for cofactor regeneration plays a vital role in the effective enzymatic C1 reduction. Hydrogenase utilizes renewable hydrogen to achieve the regeneration and supply cofactor nicotinamide adenine dinucleotide (NADH), providing a driving force for the reduction reaction to reduce the thermodynamic barrier of the reaction cascade, and making the forward reduction pathway thermodynamically feasible. Based on the regeneration of cofactor NADH by hydrogenase, and coupled with formaldehyde dehydrogenase and formolase, a favorable thermodynamic mode of the C1 reduction pathway for reducing formate to dihydroxyacetone (DHA) was designed and constructed. This resulted in accumulation of 373.19 μmol·L^–1 DHA after 2 h, and conversion reaching 7.47%. These results indicate that enzymatic utilization of hydrogen as the electron donor to regenerate NADH is of great significance to the sustainable and green development of bio-manufacturing because of its high economic efficiency, no by-products, and environment-friendly operation. Moreover, formolase efficiently and selectively fixed the intermediate formaldehyde (FALD) to DHA, thermodynamically pulled formate to efficiently reduce to DHA, and finally stored the low-grade renewable energy into chemical energy with high energy density.

Thallium is a highly toxic metal, and trace amount of thallium(I) (Tl⁺) in potable water could cause a severe water crisis, which arouses the exploitation of highly-effective technology for purification of Tl⁺ contaminated water. This report proposes the multi-layered Prussian blue (PB)-decorated composite membranes (PB_x@PDA/PEI-FP) based on the aminated filter papers for Tl⁺ uptake. Extensively characterization by Fourier transform infrared spectrometer-attenuated total reflectance, scanning electron microscope, thermogravimetric analysis, X-ray photoelectron spectroscopy and X-ray diffraction were performed to confirm the in situ growth of cubic PB crystals on filter paper membrane surfaces via the aminated layers, and the successful fabrication of multi-layered PB overcoats via the increasing of aminated layers. The effect of PB layers on Tl⁺ removal by PB_x@PDA/PEI-FP from simulated drinking water was evaluated as well as the influence of different experimental conditions. A trade-off between PB decoration layer number and PB distribution sizes is existed in Tl⁺ uptake by PB_x@PDA/PEI-FP. The double-layered PB₂@PDA/PEI-FP membrane showed the maximum sorption capacity, but its Tl⁺ uptake performance was weakened by the acid, coexisting ions (K⁺ and Na⁺) and powerful operation pressure, during filtrating a large volume of low-concentrated Tl⁺-containing water. However, the negative effect of coexisting ions on the Tl⁺ uptake could be effectively eliminated in weak alkaline water, and the Tl⁺ removal was increased up to 100% without any pressure driving for PB₂@PDA/PEI-FP membrane. Most importantly, PB₂@PDA/PEI-FP displayed the high-efficiency and high-selectivity in purifying the Tl⁺-spiked Pearl River water, in which the residual Tl⁺ in filtrate was less than 2 μg·L^–1 to meet the drinking water standard of United States Environmental Protection Agency. This work provides a feasible avenue to safeguard the drinking water in remote and underdeveloped area via the energy-free operation.

Organic matter-induced mineralization is a green and versatile method for synthesizing hybrid nanostructured materials, where the material properties are mainly influenced by the species of natural biomolecules, linear synthetic polymer, or small molecules, limiting their diversity. Herein, we adopted dendrimer poly(amidoamine) (PAMAM) as the inducer to synthesize organosilica-PAMAM network (OSPN) capsules for mannose isomerase (MIase) encapsulation based on a hard-templating method. The structure of OSPN capsules can be precisely regulated by adjusting the molecular weight and concentration of PAMAM, thereby demonstrating a substantial impact on the kinetic behavior of the MIase@OSPN system. The MIase@OSPN system was used for catalytic production of mannose from D-fructose. A mannose yield of 22.24% was obtained, which is higher than that of MIase in organosilica network capsules and similar to that of the free enzyme. The overall catalytic efficiency (k_cat/K_m) of the MIase@OSPN system for the substrate D-fructose was up to 0.556 s⁻¹·mmol⁻¹·L. Meanwhile, the MIase@OSPN system showed excellent stability and recyclability, maintaining more than 50% of the yield even after 12 cycles.

The widespread implementation of supercapacitors is hindered by the limited energy density and the pricey porous carbon electrode materials. The cost of porous carbon is a significant factor in the overall cost of supercapacitors, therefore a high carbon yield could effectively mitigate the production cost of porous carbon. This study proposes a method to produce porous carbon spheres through a spray drying technique combined with a carbonization process, utilizing renewable enzymatic hydrolysis lignin as the carbon source and KOH as the activation agent. The purpose of this study is to examine the relationship between the quantity of activation agent and the development of morphology, pore structure, and specific surface area of the obtained porous carbon materials. We demonstrate that this approach significantly enhances the carbon yield of porous carbon, achieving a yield of 22% in contrast to the conventional carbonization-activation method (9%). The samples acquired through this method were found to contain a substantial amount of mesopores, with an average pore size of 1.59 to 1.85 nm and a mesopore ratio of 25.6%. Additionally, these samples showed high specific surface areas, ranging from 1051 to 1831 m²·g⁻¹. Zinc ion hybrid capacitors with lignin-derived porous carbon cathode exhibited a high capacitance of 279 F·g⁻¹ at 0.1 A·g⁻¹ and an energy density of 99.1 Wh·kg⁻¹ when the power density was 80 kW·kg⁻¹. This research presents a novel approach for producing porous carbons with high yield through the utilization of a spray drying approach.

Bifunctional metal/zeolite materials are some of the most suitable catalysts for the direct hydroalkylation of benzene to cyclohexylbenzene. The overall catalytic performance of this reaction is strongly influenced by the hydrogenation, which is dependent on the metal sizes. Thus, systematically investigating the metal size effects in the hydroalkylation of benzene is essential. In this work, we successfully synthesized Ru and Pd nanoparticles on Sinopec Composition Materials No.1 zeolite with various metal sizes. We demonstrated the size-dependent catalytic activity of zeolite-supported Ru and Pd catalysts in the hydroalkylation of benzene, which can be attributed to the size-induced hydrogen spillover capability differences. Our work presents new insights into the hydroalkylation reaction and may open up a new avenue for the smart design of advanced metal/zeolite bi-functional catalysts.

The composition of biomass pyrolysis gas is complex, and the selective separation of its components is crucial for its further utilization. Metal-incorporated nitrogen-doped materials exhibit enormous potential, whereas the relevant adsorption mechanism is still unclear. Herein, 16 metal-incorporated nitrogen-doped carbon materials were designed based on the density functional theory calculation, and the adsorption mechanism of pyrolysis gas components H₂, CO, CO₂, CH₄, and C₂H₆ was explored. The results indicate that metal-incorporated nitrogen-doped carbon materials generally have better adsorption effects on CO and CO₂ than on H₂, CH₄, and C₂H₆. Transition metal Mo- and alkaline earth metal Mg- and Ca-incorporated nitrogen-doped carbon materials show the potential to separate CO and CO₂. The mixed adsorption results of CO₂ and CO further indicate that when the CO₂ ratio is significantly higher than that of CO, the saturated adsorption of CO₂ will precede that of CO. Overall, the three metal-incorporated nitrogen-doped carbon materials can selectively separate CO₂, and the alkaline earth metal Mg-incorporated nitrogen-doped carbon material has the best performance. This study provides theoretical guidance for the design of carbon capture materials and lays the foundation for the efficient utilization of biomass pyrolysis gas.

Membrane gas separation is considered an energy-saving technique to extract He from natural gas due to no phase change and room temperature operation. However, the membrane performance was strongly limited by the trade-off between permeance and selectivity. Herein, novel 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA)-2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (APAF)-5-amino-2-(4-aminobenzene)benzimidazole (BIA) asymmetric membranes with a thickness of 300 nm were successfully prepared by the non-solvent induced phase separation method. The membrane performance was modulated by regulating dope solution compositions (e.g., tetrahydrofuran and polymer concentration). The ideal He/CH₄ selectivity was 124 and the optimized He permeance reached 87 GPU, beyond the current upper bound. He/CH₄ selectivity was 75 and He permeance was 73 GPU for the binary mixture feed containing 0.2 mol % He. The membrane showed good resistance to CO₂ and C₂H₆, which are the typical impurities in natural gas. The 6FDA-APAF-BIA membranes have good stability (> 160 h), which can provide great potential in He extraction from natural gas.

The use of functional materials such as carbon-bismuth oxyhalides in integrated photorefineries for the clean production of fine chemicals requires restructuring. A facile biomass-assisted solvothermal fabrication of carbon/bismuth oxychloride nanocomposites (C/BiOCl) was achieved at various temperatures. Compared with BiOCl and C/BiOCl-120, C/BiOCl-180 exhibited higher crystallinity, wider visible light absorption, and a faster migration/separation rate of photoinduced carriers. For the selective C–C bond cleavage of biomass-based feedstocks photocatalyzed by C/BiOCl-180, the xylose conversion and lactic acid yield were 100% and 92.5%, respectively. C/BiOCl-180 efficiently converted different biomass-based monosaccharides to lactic acid, and the efficiency of pentoses was higher than that of hexoses. Moreover, lactic acid synthesis was favored by all active radicals including superoxide ion (·O₂⁻), holes (h⁺), hydroxyl radical (·OH), and singlet oxygen (¹O₂), with ·O₂⁻ playing a key role. The fabricated photocatalyst was stable, economical, and recyclable. The use of biomass-derived monosaccharides for the clean production of lactic acid via the C/BiOCl-180 photocatalyst has opened new research horizons for the investigation and application of C–C bond cleavage in biomass-based feedstocks.

Metal-organic framework/organosilica hybrid membranes on tubular ceramic substrates have shown great potential for the implementation of membrane technology in practical gas separation projects due to their higher permeance compared to commercial polymers. However, the selectivities of the reported membranes are moderate. Here, we have incorporated urea-modulated metal-organic frameworks into organosilica membranes to greatly enhance its separation performance. The urea-modulated metal-organic frameworks exhibit less-defined edges of crystallographic facets and high defect density. They can be well-dispersed in the organosilica layer, which substantially suppresses the interfacial defects between metal-organic frameworks and organosilica, which is beneficial for improving the selectivity of membranes for gas separation. The results have shown that the enhanced ideal selectivity of H₂/CH₄ was 165 and that of CO₂/CH₄ was 43, with H₂ permeance of about 1.25 × 10⁻⁶ mol·m⁻²·s⁻¹·Pa⁻¹ and CO₂ permeance of 3.27 × 10⁻⁷ mol·m⁻²·s⁻¹·Pa⁻¹ at 0.2 MPa and 25 °C. In conclusion, the high level of hybrid membranes can be used to separate H₂ (or CO₂) from the binary gas mixture H₂/CH₄ (or CO₂/CH₄), which is important for gas separation in practical applications. Moreover, the simple and feasible modulation of metal-organic framework is a promising strategy to tune different metal-organic frameworks for membranes according to the actual demands.

This study utilized a thermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue (VR) and low-density polyethylene (LDPE) polymers. The kinetic parameters were calculated using the Friedman technique. To demonstrate the interactive effects between LDPE and VR during the co-pyrolysis process, the disparity in mass loss and mass loss rate between the experimental and calculated values was computed. The co-pyrolysis curves obtained through estimation and experimentation exhibited significant deviations, which were influenced by temperature and mixing ratio. A negative synergistic interaction was observed between LDPE and VR, although this inhibitory effect could be mitigated or eliminated by reducing the LDPE ratio in the mixture and increasing the co-pyrolysis temperature. The co-pyrolysis process resulted in a reduction in carbon residue, which could be attributed to the interaction between LDPE and the heavy fractions, particularly resin and asphaltene, present in VR. These findings align with the pyrolysis behaviors exhibited by the four VR fractions. Furthermore, it was observed that the co-pyrolysis process exhibited lower activation energy as the VR ratio increased, indicating a continuous enhancement in the reactivity of the mixed samples during co-pyrolysis.

Regulation of aluminum distribution in zeolite framework is an effective method for improving its catalytic performance for propane aromatization. Herein, we found that recrystallization and post-realuminization of ZSM-5 cannot only create hollow structures to enhance the diffusion ability, but also adjust the content and position of paired aluminum species in its framework. Various characterizations results confirmed that increase of paired aluminum content and inducement of more aluminum atoms sited in the intersection cavity are beneficial to the formation of aromatic products in propane aromatization. As a result, the hollow-structured ZSM-5 zeolite with more paired aluminum (H-200-hollow) showed higher propane conversion and aromatics selectivity than other samples at the same conditions. The catalytic performance of H-200-hollow can be further improved by ion-exchanging with a small amount of Ga(III) species. The propane conversion and aromatics selectivity of Ga-200-hollow reached as high as 95% and 70%, respectively, at 540 °C and 1 atm.

Amino acids are important nitrogen carriers in biomass and entail a broad spectrum of industrial uses, most notably as food additives, pharmaceutical ingredients, and raw materials for bio-based plastics. Attaining detailed information in regard to the fragmentation of amino acids is essential to comprehend the nitrogen transformation chemistry at conditions encountered during hydrothermal and pyrolytic degradation of biomass. The underlying aim of this review is to survey literature studies pertinent to the complex structures of amino acids, their formation yields from various categories of biomass, and their fragmentation routes at elevated temperatures and in the aqueous media. Two predominant degradation reactions ensue in the decomposition of amino acids, namely deamination and decarboxylation. Notably, minor differences in structure can greatly affect the fate for each amino acid. Moreover, amino acids, being nitrogen-rich compounds, play pivotal roles across various fields. There is a growing interest in producing varied types and configurations of amino acids. Microbial fermentation appears to a viable approach to produce amino acids at an industrial scale. One innovative method under investigation is catalytic synthesis using renewable biomass as feedstocks. Such a method taps into the inherent nitrogen in biomass sources like chitin and proteins, eliminating the need for external nitrogen sources. This environmentally friendly approach is in line with green chemistry principles and has been gathering momentum in the scientific community.

During steam reforming, the performance of a catalyst and amount/property of coke are closely related to reaction intermediates reaching surface of a catalyst. Herein, modification of reaction intermediates by placing Mg-Al-hydrotalcite above Ni/KIT-6 catalyst in steam reforming of glycerol was conducted at 300 to 600 °C. The results revealed that the catalytic activity of Ni/KIT-6 in the lower bed was enhanced with either Mg₁-Al₅-hydrotalcite (containing more acidic sites) or Mg₅-Al₁-hydrotalcite (containing more alkaline sites) as upper-layer catalyst. The in situ infrared characterization of steam reforming demonstrated that Mg-Al-hydrotalcite catalyzed the deoxygenation of glycerol, facilitating the reforming of the partially deoxygenated intermediates over Ni/KIT-6. Mg-Al-hydrotalcite as protective catalyst, however, did not protect the Ni/KIT-6 from formation of more coke. Nonetheless, this did not lead to further deactivation of Ni/KIT-6 while Mg₅-Al₁-hydrotalcite even substantially enhanced the catalytic stability, even though the coke was much more significant than that in the use of single Ni/KIT-6 (52.7% vs. 28.6%). The reason beneath this was change of the property of coke from more aliphatic to more aromatic. Mg₅-Al₁-hydrotalcite catalyzed dehydration of glycerol, producing dominantly reaction intermediates bearing C=C, which formed the catalytic coke of with carbon nanotube as the main form with smooth outer walls as well as higher aromaticity, C/H ratio, crystallinity, crystal carbon size, thermal stability, and resistivity toward oxidation on Ni/KIT-6 in the lower bed. In comparison, the abundance of acidic sites on Mg₁-Al₅-hydrotalcite catalyzed the formation of more oxygen-containing species, leading to the formation of carbon nanotubes of rough surface on Ni/KIT-6.

The nitridation reaction of calcium carbide and N₂ at high temperatures is the key step in the production of lime-nitrogen. However, the challenges faced by this process, such as high energy consumption and poor product quality, are mainly attributed to the lack of profound understanding of the reaction. This study aimed to improve this process by investigating the non-isothermal kinetics and reaction characteristics of calcium carbide nitridation reaction at different heating rates (10, 15, 20, and 30 °C·min⁻¹) using thermogravimetric analysis. The kinetic equation for the nitridation reaction of additive-free calcium carbide sample was obtained by combining model-free methods and model-fitting method. The effect of different calcium-based additives (CaCl₂ and CaF₂) on the reaction was also investigated. The results showed that the calcium-based additives significantly reduced reaction temperature and activation energy E_a by about 40% with CaF₂ and by 55%–60% with CaCl₂. The reaction model f(α) was also changed from contracting volume (R3) to 3-D diffusion models with D3 for CaCl₂ and D4 for CaF₂. This study provides valuable information on the mechanism and kinetics of calcium carbide nitridation reaction and new insights into the improvement of the lime-nitrogen process using calcium-based additives.

Herein, the influence of the concentration design and comprehensive performance of the sulfate-phosphoric mixed acid system electrolyte is investigated to realize an electrolyte that maintains high energy density and stable operation at high temperatures. Static stability tests have shown that VOPO₄ precipitation occurs only with vanadium(V) electrolyte. The concentration of vanadium ion of 2.0–2.2 mol·L^–1, phosphoric acid of 0.10–0.15 mol·L^–1, and sulfuric acid of 2.5–3.0 mol·L^–1 are suitable for a vanadium redox flow battery in the temperature range from –20 to 50 °C. The equations for predicting the viscosity and conductivity of electrolytes are obtained by the response surface method. The optimized electrolyte overcomes precipitation generation. It has 2.8 times higher energy density than the non-phosphate electrolyte, and a coulomb efficiency of 94.0% at 50 °C. The sulfate-phosphoric mixed acid system electrolyte promotes the electrode reaction process, increases the current density, and reduces the resistance. This work systematically optimizes the concentrations of composition of positive and negative vanadium electrolytes with mixed sulfate-phosphoric acid. It provides a basis for the different valence states and comprehensive properties of sulfate-phosphoric mixed acid system vanadium electrolytes under extreme environments, guiding engineering applications.

Methanol-to-olefins, as a promising non-oil pathway for the synthesis of light olefins, has been successfully industrialized. The accurate prediction of process variables can yield significant benefits for advanced process control and optimization. The challenge of this task is underscored by the failure of traditional methods in capturing the complex characteristics of industrial processes, such as high nonlinearities, dynamics, and data distribution shift caused by diverse operating conditions. In this paper, we propose a novel hybrid spatial-temporal deep learning prediction model to address these issues. Firstly, a unique data normalization technique called reversible instance normalization is employed to solve the problem of different data distributions. Subsequently, convolutional neural network integrated with the self-attention mechanism are utilized to extract the temporal patterns. Meanwhile, a multi-graph convolutional network is leveraged to model the spatial interactions. Afterward, the extracted temporal and spatial features are fused as input into a fully connected neural network to complete the prediction. Finally, the outputs are denormalized to obtain the ultimate results. The monitoring results of the dynamic trends of process variables in an actual industrial methanol-to-olefins process demonstrate that our model not only achieves superior prediction performance but also can reveal complex spatial-temporal relationships using the learned attention matrices and adjacency matrices, making the model more interpretable. Lastly, this model is deployed onto an end-to-end Industrial Internet Platform, which achieves effective practical results.

Excitonic devices are an emerging class of technology that utilizes excitons as carriers for encoding, transmitting, and storing information. Van der Waals heterostructures based on transition metal dichalcogenides often exhibit a type II band alignment, which facilitates the generation of interlayer excitons. As a bonded pair of electrons and holes in the separation layer, interlayer excitons offer the chance to investigate exciton transport due to their intrinsic out-of-plane dipole moment and extended exciton lifetime. Furthermore, interlayer excitons can potentially analyze other encoding strategies for information processing beyond the conventional utilization of spin and charge. The review provided valuable insights and recommendations for researchers studying interlayer excitonic devices within van der Waals heterostructures based on transition metal dichalcogenides. Firstly, we provide an overview of the essential attributes of transition metal dichalcogenide materials, focusing on their fundamental properties, excitonic effects, and the distinctive features exhibited by interlayer excitons in van der Waals heterostructures. Subsequently, this discourse emphasizes the recent advancements in interlayer excitonic devices founded on van der Waals heterostructures, with specific attention is given to the utilization of valley electronics for information processing, employing the valley index. In conclusion, this paper examines the potential and current challenges associated with excitonic devices.

We report results from computational modeling of the relative stability of germanosilicate SCM-15 structure due to different distribution of germanium heteroatoms in the double four-member rings (D4Rs) of the framework and the orientation of the structure directing agent (SDA) molecules in the as-synthesized zeolite. The calculated relative energies of the bare zeolite framework suggest that structures with germanium ions clustered in the same D4Rs, e.g., with large number of Ge–O–Ge contacts, are the most stable. The simulations of various orientations of the SDA in the pores of the germanosilicate zeolite show different stability order—the most stable models are the structures with germanium spread among all D4Rs. Thus, for SCM-15 the stabilization due to the presence of the SDA and their orientation, is thermodynamic factor directing both the formation of specific framework type and Ge distribution in the framework during the synthesis. The relative stability of bare structures with different germanium distribution is of minor importance. This differs from SCM-14 germanosilicate, reported earlier, for which the stability order is preserved in presence of SDA. Thus, even for zeolites with the same chemical composition and SDA, the characteristics of their framework lead to different energetic preference for germanium distribution.

Based on its band alignment, p-type nickel oxide (NiO_x) is an excellent candidate material for hole transport layers in crystalline silicon heterojunction solar cells, as it has a small ΔE_V and large ΔE_C with crystalline silicon. Herein, to overcome the poor hole selectivity of stoichiometric NiO_x due to its low carrier concentration and conductivity, silver-doped nickel oxide (NiO_x:Ag) hole transport layers with high carrier concentrations were prepared by co-sputtering high-purity silver sheets and pure NiO_x targets. The improved electrical conductivity of NiO_x was attributed to the holes generated by the Ag⁺ substituents for Ni²⁺, and moreover, the introduction of Ag⁺ also increased the amount of Ni³⁺ present, both of which increased the carrier concentration in NiO_x. Ag⁺ doping also reduced the c-Si/NiO_x contact resistivity and improved the hole-selective contact with NiO_x. Furthermore, the problems of particle clusters and interfacial defects on the surfaces of NiO_x:Ag films were solved by UV-ozone oxidation and high-temperature annealing, which facilitated separation and transport of carriers at the c-Si/NiO_x interface. The constructed c-Si/NiO_x:Ag solar cell exhibited an increase in open-circuit voltage from 490 to 596 mV and achieved a conversion efficiency of 14.4%.

Heteroatom doping and defect engineering have been proposed as effective ways to modulate the energy band structure and improve the photocatalytic activity of g-C₃N₄. In this work, ultrathin defective g-C₃N₄ was successfully prepared using cold plasma. Plasma exfoliation reduces the thickness of g-C₃N₄ from 10 nm to 3 nm, while simultaneously introducing a large number of nitrogen defects and oxygen atoms into g-C₃N₄. The amount of doped O was regulated by varying the time and power of the plasma treatment. Due to N vacancies, O atoms formed strong bonds with C atoms, resulting in O doping in g-C₃N₄. The mechanism of plasma treatment involves oxygen etching and gas expansion. Photocatalytic experiments demonstrated that appropriate amount of O doping improved the photocatalytic degradation of rhodamine B compared with pure g-C₃N₄. The introduction of O optimized the energy band structure and photoelectric properties of g-C₃N₄. Active species trapping experiments revealed ·O₂^– as the main active species during the degradation.

Polymers of intrinsic microporosity shows great potential for dye adsorption and magnetic Fe₃O₄ are easy to be separated. In this work, hydrolyzed polymers of intrinsic microporosity-1/Fe₃O₄ composite adsorbents were prepared by phase inversion and hydrolysis process for cationic dye adsorption. The chemical structure and morphology of the composite adsorbents were systematically characterized by several characterization methods. Using methylene blue as the target dye, the influences of solution pH, contact time, initial dye concentration, and system temperature on the methylene blue adsorption process were investigated. The incorporation of Fe₃O₄ particle into hydrolyzed polymers of intrinsic microporosity-1 endow the adsorbent with high magnetic saturation (20.7 emu·g^–1) which allows the rapid separation of the adsorbent. Furthermore, the adsorption process was simulated by adsorption kinetics, isotherms and thermodynamics to gain insight onto the intrinsic adsorption mechanism. In addition, the composite adsorbents are able to selectively adsorb cationic dyes from mixed dyes solution. Hydrolyzed polymers of intrinsic microporosity/Fe₃O₄ shows only a slight decrease for methylene blue adsorption after 10 adsorption/regeneration cycles, demonstrating the outstanding regeneration performance. The high adsorption capacity, outstanding regeneration ability, together with simple preparation method, endow the composite adsorbents great potential for selective removal of cationic dyes in wastewater system.

Surface engineering and Cu valence regulation are essential factors in improving the C₂ selectivity during the electrochemical reduction of CO₂. Herein, we present a sea urchin-like CuO/Cu₂O catalyst derived from rhombic dodecahedra Cu₂O through one-step oxidation/etching method where the mixed Cu⁺/Cu⁰ states are formed via in situ reduction during electrocatalysis. The combined effects of the morphology and the mixed Cu⁺/Cu⁰ states on C–C coupling are evaluated by the Faradaic efficiency of C₂ and the C₂/C₁ ratio obtained in an H-cell. R-CuO/Cu₂O exhibited 49.5% Faradaic efficiency of C₂ with a C₂/C₁ ratio of 3.1 at −1.4 V vs. reversible hydrogen electrode, which are 1.5 and 3.2 times higher than those of R-Cu₂O, respectively. Using a flow-cell, 68.0% Faradaic efficiency of C₂ is achieved at a current density of 500 mA·cm⁻². The formation of the mixed Cu⁺/Cu⁰ states was confirmed by in situ Raman spectra. Additionally, the sea urchin-like structure provides more active sites and enables faster electron transfer. As a result, the excellent C₂ production on R-CuO/Cu₂O is primarily attributed to the synergistic effects of the sea urchin-like structure and the stable mixed Cu⁺/Cu⁰ states. Therefore, this work presents an integrated strategy for developing Cu-based electrocatalysts for C₂ production through electrochemical CO₂ reduction.

The electrocatalytic hydrogen evolution reaction is a crucial technique for green hydrogen production. However, finding affordable, stable, and efficient catalyst materials to replace noble metal catalysts remains a significant challenge. Recent experimental breakthroughs in the synthesis of two-dimensional bilayer borophene provide a theoretical framework for exploring their physical and chemical properties. In this study, we systematically considered nine types of bilayer borophenes as potential electrocatalysts for the hydrogen evolution reaction. Our first-principles calculations revealed that bilayer borophenes exhibit high stability and excellent conductivity, possessing a relatively large specific surface area with abundant active sites. Both surface boron atoms and the bridge sites between two boron atoms can serve as active sites, displaying high activity for the hydrogen evolution reaction. Notably, the Gibbs free energy change associated with adsorption for these bilayer borophenes can reach as low as ‒0.002 eV, and the Tafel reaction energy barriers are lower (0.70 eV) than those on Pt. Moreover, the hydrogen evolution reaction activity of these two-dimensional bilayer borophenes can be described by engineering their work function. Additionally, we considered the effect of pH on hydrogen evolution reaction activity, with significant activity observed in an acidic environment. These theoretical results reveal the excellent catalytic performance of two-dimensional bilayer borophenes and provide crucial guidance for the experimental exploration of multilayer boron for various energy applications.

Typically, the hydroxide agents, such as sodium hydroxide and potassium hydroxide, which have corrosive properties, are used in the carbon activation process. In this study, potassium oxalate (K₂C₂O₄), a less toxic and non-corrosive activating reagent, was used to synthesize activated carbon from the solid residue after autohydrolysis treatment. The effect of the autohydrolysis treatment and the ratio of the K₂C₂O₄/solid residue are presented in this study. Moreover, the comparison between the activated carbon from bamboo and biochar from the solid residue are also reported. The resulting activated carbon from the solid residue exhibited a high surface area of up to 1432 m²·g^–1 and a total pore volume of up to 0.88 cm³·g^–1. The autohydrolysis treatment enhanced the microporosity properties compared to those without pretreatment of the activated carbon. The microporosity of the activated carbon from the solid residue was dominated by the pore width at 0.7 nm, which is excellent for CO₂ storage. At 25 °C and 1.013 × 10⁵ Pa, the CO₂ captured reached up to 4.1 mmol·g^–1. On the other hand, the ratio between K₂C₂O₄ and the solid residue has not played a critical role in determining the porosity properties. The ratio of the K₂C₂O₄/solid residue of 2 could help the carbon material reach a highly microporous textural property that produces a high carbon capture capacity. Our finding proved the benefit of using the solid residue from the autohydrolysis treatment as a precursor material and offering a more friendly and sustainable activation carbon process.

A nitrogen-doped carbon microsphere sorbent with a hierarchical porous structure was synthesized via aggregation-hydrothermal carbonization. The Hg⁰ adsorption performance of the nitrogen-doped carbon microsphere sorbent was tested and compared with that of the coconut shell activated carbon prepared in the laboratory. The effect of H₂S on Hg⁰ adsorption was also investigated. The nitrogen-doped carbon microsphere sorbent exhibited superior mercury removal performance compared with that of coconut shell activated carbon. In the absence of H₂S at a low temperature (≤ 100 °C), the Hg⁰ removal efficiency of the nitrogen-doped carbon microsphere sorbent exceeded 90%. This value is significantly higher than that of coconut shell activated carbon, which is approximately 45%. H₂S significantly enhanced the Hg⁰ removal performance of the nitrogen-doped carbon microsphere sorbent at higher temperatures (100–180 °C). The hierarchical porous structure facilitated the diffusion and adsorption of H₂S and Hg⁰, while the nitrogen-containing active sites significantly improved the adsorption and dissociation capabilities of H₂S, contributing to the generation of more active sulfur species on the surface of the nitrogen-doped carbon microsphere sorbent. The formation of active sulfur species and HgS on the sorbent surface was further confirmed using X-ray photoelectron spectroscopy and Hg⁰ temperature-programmed desorption tests. Density functional theory was employed to elucidate the adsorption and transformation of Hg⁰ on the sorbent surface. H₂S adsorbed and dissociated on the sorbent surface, generating active sulfur species that reacted with gaseous Hg⁰ to form HgS.

Eucalyptus species are extensively cultivated trees commonly used for timber production, firewood, paper manufacturing, and essential nutrient extraction, while lacking consumption of the leaves increases soil acidity. The objective of this study was to recover bio-oil through microwave pyrolysis of eucalyptus camaldulensis leaves. The effects of microwave power (450, 550, 650, 750, and 850 W), pyrolysis temperature (500, 550, 600, 650, and 700 °C), and silicon carbide amount (10, 25, 40, 55, and 70 g) on the products yields and bio-oil constituents were investigated. The yields of bio-oil, gas, and residue varied within the ranges of 19.8–39.25, 33.75–46.7, and 26.0–33.5 wt %, respectively. The optimal bio-oil yield of 39.25 wt % was achieved at 650 W, 600 °C, and 40 g. The oxygenated derivatives, aromatic compounds, aliphatic hydrocarbons, and phenols constituted 40.24–74.25, 3.25–23.19, 0.3–9.77, and 1.58–7.75 area % of the bio-oils, respectively. Acetic acid (8.17–38.18 area %) was identified as a major bio-oil constituent, and hydrocarbons with carbon numbers C₁ and C₂ were found to be abundant. The experimental results demonstrate the potential of microwave pyrolysis as an eco-friendly and efficient way for converting eucalyptus waste into valuable bio-oil, contributing to the sustainable utilization of biomass resources.

The aluminum-water system is a promising propellant due to high energy and low signal characteristics, and the gel form is easier to store and utilize. In this work, hydrogels of water and aluminum particles were prepared using the low-molecular-weight gellant agarose. The various physical properties of gel systems, including the water loss rate, phase transition temperature, and centrifugal stability at different gellant and aluminum contents, were examined. Rheological properties were assessed through shear thinning tests, thixotropy tests, strain sweep analysis, and frequency sweep experiments. The microstructure of the gel was obtained through scanning electron microscopy images. The results show that the aluminum-hydrogel network structure is composed of micron-scale aluminum and agarose nanosheets, and the unique micro-nanostructure endows the gel with excellent mechanical strength and thermal stability, which improve with increasing gellant and aluminum contents. Notably, the gel with 2% agarose and 20% aluminum had the best performance; the storage modulus reached 90647 Pa, which was within the linear viscoelastic region, and the maximum withstand pressure was 111.2 kPa, which was 118.8% greater than that of the pure hydrogel. Additionally, the gel demonstrates remarkable shear thinning behavior and can undergo gel-sol transformation upon shearing or heating to exceeding 114 °C.

The fabrication of suitable MFI zeolites to effectively produce para-xylene through the alkylation between toluene and methanol is highly desired. Here, the two-dimensional pillared MFI zeolite was modified by silicalite-1, and its morphology and structure were systematically investigated by tuning the concentration of Si species during the secondary crystallization process. The MFI zeolites were characterized by X-ray diffraction, transmission electron microscopy, pyridine-infrared and N₂ adsorption-desorption isotherms. The characterization results showed that the external Brønsted acid sites of surface passivated P-MFI-x samples have been successfully shielded. Interestingly, the P-MFI-23 showed long lifetime and high selectivity of para-xylene (about 35%) based on the cooperation between opened interlamellar structure and passivated silicalite-1 layer. It was found that the accumulated hard coke in the interior of MFI zeolites not only blocked the channels of zeolites but also covered the acidic sites, resulting in the deactivation of catalyst. Furthermore, the highest selectivity of para-xylene (about 48%) can be achieved for P-MFI-30 under harsh reaction condition, which also exhibited excellent regeneration property in the alkylation reaction between toluene and methanol. The strategy described in present research may open a window for the design of other advanced materials.

Sodium-ion batteries (SIBs) have garnered significant interest in energy storage due to their similar working mechanism to lithium ion batteries and abundant reserves of sodium resource. Exploring facile synthesis of a carbon-based anode materials with capable electrochemical performance is key to promoting the practical application of SIBs. In this work, a combination of petroleum pitch and recyclable sodium chloride is selected as the carbon source and template to obtain hard carbon (HC) anode for SIBs. Carbonization times and temperatures are optimized by assessing the sodium ion storage behavior of different HC materials. The optimized HC exhibits a remarkable capacity of over 430 mAh·g^–1 after undergoing full activation through 500 cycles at a density of current of 0.1 A·g^–1. Furthermore, it demonstrates an initial discharge capacity of 276 mAh·g^–1 at a density of current of 0.5 A·g^–1. Meanwhile, the optimized HC shows a good capacity retention (170 mAh·g^–1 after 750 cycles) and a remarkable rate ability (166 mAh·g^–1 at 2 A·g^–1). The enhanced capacity is attributed to the suitable degree of graphitization and surface area, which improve the sodium ion transport and storage.