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.

Layered double hydroxides have demonstrated great potential for the oxygen evolution reaction, which is a crucial half-reaction of overall water splitting. However, it remains challenging to apply layered double hydroxides in other electrochemical reactions with high efficiency and stability. Herein, we report two-dimensional multifunctional layered double hydroxides derived from metal-organic framework sheet precursors supported by nanoporous gold with high porosity, which exhibit appealing performances toward oxygen/hydrogen evolution reactions, hydrazine oxidation reaction, and overall hydrazine splitting. The as-prepared catalyst only requires an overpotential of 233 mV to reach 10 mA·cm^–2 toward oxygen evolution reaction. The overall hydrazine splitting cell only needs a cell voltage of 0.984 V to deliver 10 mA·cm^–2, which is far more superior than that of the overall water splitting system (1.849 V). The appealing performances of the catalyst can be contributed to the synergistic effect between the metal components of the layered double hydroxides and the supporting effect of the nanoporous gold substrate, which could endow the sample with high surface area and excellent conductivity, resulting in superior activity and stability.

CO₂ capture is one of the key technologies for dealing with the global warming and implementing low-carbon development strategy. The emergence of ionic metal-organic frameworks (I-MOFs) has diversified the field of porous materials, which have been extensively applied for gas adsorption and separation. In this work, amino-functionalized imidazolium ionic liquid as organic monodentate ligand was used for one step synthesis microporous Cu based I-MOFs. Precise tuning of the adsorption properties was obtained by incorporating aromatic anions, such as phenoxy, benzene carboxyl, and benzene sulfonic acid group into the I-MOFs via a facile ion exchange method. The new I-MOFs showed high thermal stability and high capacity of 5.4 mmol·g^–1 under atmospheric conditions for selective adsorption of CO₂. The active sites of microporous Cu-MOF are the ion basic center and unsaturated metal, and electrostatic attraction and hydroxyl bonding between CO₂ and modified functional sulfonic groups are responsible for the adsorption. This work provides a feasible strategy for the design of I-MOF for functional gas capture.

To enhance the yields of benzene, toluene, and xylene in tetralin hydrocracking, the effect of the support acid properties of NiMo catalysts on hydrocracking performance of tetralin were investigated in this study. NaY zeolites were modified by hydrothermal treatment to form USY zeolites at different temperatures and adjust the type and amount of acid. In addition, H-Beta was loaded into the USY to further adjust the acidic properties of the catalysts. The result shows that when the total B acid content of the catalyst is maintained between 150 and 200 μmol·g^–1, the total acid amount is maintained between 1.7 and 1.9 mmol·g^–1, and the L/B (L and B acids) ratio is maintained between 1.5 and 2, the catalysts have favorable performances on tetralin hydrocracking. Under this condition, the catalysts have a yield of benzene, toluene, and xylene higher than 30 wt % and a selectivity for benzene, toluene, and xylene higher than 35%. The tetralin conversion is greater than 85 wt %. The AB6 catalyst obtains the best hydrocracking effect with the conversion of tetralin reaching 90.24 wt %, the yields of benzene, toluene, and xylene reaching 33.58 wt %, and the selectivity of benzene, toluene, and xylene reaching 37.21%, respectively.

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.

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.

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.

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.

Decalin is considered as an important compound of high-energy-density endothermic fuel, which is an ideal on-board coolant for thermal management of advanced aircraft. However, decalin contains two isomers with a tunable composition, and their effects on the pyrolysis performance, such as the heat sink and coking tendency have not been demonstrated. Herein, we investigated the pyrolysis of decalin isomers, i.e., cis-decalin, trans-decalin and their mixtures (denoted as mix-decalin), in order to clarify the effects of the cis-/trans-structures on the pyrolysis performance of decalin fuels. The pyrolysis results confirmed that conversion of the tested fuels (600–725 °C, 4 MPa) decreased in the order cis-decalin > mix-decalin > trans-decalin. Detailed analyses of the pyrolysis products were used to compare the product distributions from cis-decalin, mix-decalin and trans-decalin, and the yields of some typical components (such as cyclohexene, 1-methylcyclohexene, benzene and toluene) showed significant differences, which could be ascribed to deeper cracking of cis-decalin. Additionally, the heat sinks and coking tendencies of the decalins decreased in the order cis-decalin > mix-decalin > trans-decalin. This work demonstrates the relationship between the cis/trans structures and the pyrolysis performance of decalin, which provides a better understanding of the structure-activity relationships of endothermic hydrocarbon fuels.

Biomass-derived carbon materials for lithium-ion batteries emerge as one of the most promising anodes from sustainable perspective. However, improving the reversible capacity and cycling performance remains a long-standing challenge. By combining the benefits of K₂CO₃ activation and KMnO₄ hydrothermal treatment, this work proposes a two-step activation method to load MnO₂ charge transfer onto biomass-derived carbon (KAC@MnO₂). Comprehensive analysis reveals that KAC@MnO₂ has a micro-mesoporous coexistence structure and uniform surface distribution of MnO₂, thus providing an improved electrochemical performance. Specifically, KAC@MnO₂ exhibits an initial charge-discharge capacity of 847.3/1813.2 mAh·g^–1 at 0.2 A·g^–1, which is significantly higher than that of direct pyrolysis carbon and K₂CO₃ activated carbon, respectively. Furthermore, the KAC@MnO₂ maintains a reversible capacity of 652.6 mAh·g^–1 after 100 cycles. Even at a high current density of 1.0 A·g^–1, KAC@MnO₂ still exhibits excellent long-term cycling stability and maintains a stable reversible capacity of 306.7 mAh·g^–1 after 500 cycles. Compared with reported biochar anode materials, the KAC@MnO₂ prepared in this work shows superior reversible capacity and cycling performance. Additionally, the Li⁺ insertion and de-insertion mechanisms are verified by ex situ X-ray diffraction analysis during the charge-discharge process, helping us better understand the energy storage mechanism of KAC@MnO₂.

In this study, we synthesize a catalyst comprising cobalt nanoparticles supported on MXene by pyrolyzing a composite in a N₂ environment. Specifically, the composite comprises a bimetallic Zn/Co zeolitic imidazole framework grown in situ on the outer surface of MXene. The catalytic efficiency of the catalyst is tested for the self-coupling of 4-methoxybenzylamine to produce value-added imine, where atmospheric oxygen (1 atm) is used as the oxidant. Based on the results, the catalyst displayed impressive catalytic activity, achieving 95.4% yield of the desired imine at 383 K for 8 h. Furthermore, the catalyst showed recyclability and tolerance toward benzylamine substrates with various functional groups. The outstanding performance of the catalyst is primarily attributed to the synergetic catalytic effect between the cobalt nanoparticles and MXene support, while also benefiting from the three-dimensional porous structure. Additionally, a preliminary investigation of potential reaction mechanisms is conducted.

The cycloaddition reaction between epoxides and CO₂ is an effective method to utilize CO₂ resource. Covalent organic frameworks (COFs) provide a promising platform for the catalytic CO₂ transformations on account of their remarkable chemical and physical properties. Herein, a family of novel vinylene-linked ionic COFs named TE-COFs (TTE-COF, TME-COF, TPE-COF, TBE-COF) has been facilely synthesized from N-ethyl-2,4,6-trimethylpyridinium bromide and a series of triphenyl aromatic aldehydes involving different numbers of nitrogen atoms in the central aromatic ring. The resulting catalyst TTE-COF with excellent adsorption capacity (45.6 cm³·g^–1, 273 K) exhibited outstanding catalytic performance, remarkable recyclability and great substrate tolerance. Moreover, it was also observed that the introduction of nitrogen atom in the precursor led to a great improvement in the crystallinity and CO₂ adsorption capacity of TE-COFs, thus resulting to a progressively improved catalytic performance. This work not only illustrated the influence of monomer nitrogen content on the crystallinity and CO₂ adsorption capacity of TE-COFs but also provided a green heterogeneous candidate for catalyzing the cycloaddition between CO₂ and epoxides, which shed a light on improving the catalytic performance of the CO₂ cycloaddition reaction by designing the covalent organic frameworks structures.

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.

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.

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.

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.

In a dual-chamber photocatalytic fuel cell device, polyvinyl alcohol degradation and H₂ evolution were concurrently achieved. The setup involved commercial P25 as the photoanode and Ag@Fe₂O₃ nanoparticles as the cathode. Additionally, the feasibility of a Fenton-like reaction in the cathode, utilizing Fe²⁺ ions and pumped O₂, was demonstrated. Different cathode materials, polyvinyl alcohol types, and pH values’ effects were assessed on device performance. Quenching tests highlighted photoinduced holes (h⁺) and OH· radicals as pivotal contributions to polyvinyl alcohol degradation. Long-term stability of the device was established through cycling experiments.

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.

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.

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.

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.

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.

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.

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.

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%.

In this study, Mn-Na₂WO₄/γ-Al₂O₃ catalysts with varying ratios of Mn/W were prepared using the dry impregnation method. These catalysts were then tested for their suitability in the oxidative coupling of methane reaction. The X-ray photoelectron results revealed the presence of the tetrahedral WO₄^2– phase in all prepared catalysts. It is believed that the presence of this phase is associated with high catalyst activity, indicating the potential of the catalysts for the desired reaction. The activity results show that the catalyst with a high Mn/W ratio exhibited higher activity at 800 °C, whereas the catalyst with a low Mn/W ratio showed greater activity at 850 °C. This suggests that the Mn/W ratio influences the reaction temperature at which the catalyst is most active. Furthermore, the X-ray diffraction results of the treated catalysts revealed that the catalyst with a high Mn/W ratio exhibited more MnAl₂O₄ at 800 °C, whereas the catalyst with a low Mn/W ratio contained more MnWO₄ at 850 °C. The results suggest that the presence of MnAl₂O₄ sites may promote a more facile Mn²⁺ ↔ Mn³⁺ cycle at lower temperatures than the MnWO₄ site, potentially contributing to the enhanced catalyst activity in the oxidative coupling of methane reaction at 800 °C.