Electrochemical CO₂ reduction (CO₂RR) offers a compelling route for converting CO₂ into value-added chemicals using renewable electricity, yet its practical deployment is fundamentally constrained by sluggish kinetics, complex electrified interfaces, and limited control over product selectivity. Gold-based catalysts have long been regarded as benchmarks for CO-selective CO₂RR; however, growing evidence indicates that their catalytic behavior is not dictated by intrinsic adsorption energetics alone, but instead emerges from a tightly coupled interplay between surface structure, dynamic interface evolution, and the local reaction microenvironment. In this review, we critically examine recent advances in Au-based CO₂RR catalysts through the unifying lens of surface-interface control, encompassing morphology and defect engineering, alloy and cluster design, molecular surface modification, electrolyte cation regulation, and tandem or cascade catalytic architectures. Particular emphasis is placed on mechanistic insights derived from operando spectroscopy and kinetic analysis, which reveal dynamic phenomena, such as water-mediated proton transfer, CO-induced site blocking, surface reconstruction, and the breakdown of single-parameter activity descriptors. By integrating catalyst design with interfacial chemistry, mass transport, and solvation effects, this review establishes a unified mechanistic framework for understanding CO₂ electroreduction on gold-based catalysts and distills general principles for the rational design of efficient and selective electrochemical CO₂ conversion systems.

Metal-organic frameworks (MOFs) have emerged as a versatile platform for electrochemical CO₂ reduction (CO₂RR), offering a unique combination of molecular-level tunability and solid-state robustness. This review surveys recent advances in MOF-based and MOF-derived catalysts from the perspective of solid-state chemistry, with particular emphasis on how structural parameters govern catalytic pathways and performance. Rather than merely summarizing material systems, we critically examine how the engineering of metal nodes, from isolated single sites to cooperative bimetallic motifs, modulates the adsorption energetics of key reaction intermediates. We further discuss the synergistic roles of ligand functionalization, pore architecture, and defect chemistry in regulating the local electronic structure and microenvironment of active sites. By correlating coordination geometry, charge-transfer behavior, and intermediate binding with catalytic activity and product selectivity, this review establishes a structure-activity framework to guide the rational design of next-generation MOF-based electrocatalysts for CO₂RR.

Ammonia is a cornerstone of global agriculture and is expected to become a carbon-neutral energy carrier. The high-energy-consuming Haber-Bosch method and the widespread nitrate pollution in water bodies have presented severe energy and environmental challenges. Electrocatalytic nitrate reduction reaction (NO₃RR) is an attractive protocol that combines wastewater treatment with green ammonia synthesis. Transition metal phosphides (TMPs) demonstrate pronounced catalytic activity and selectivity in NO₃RR due to their controllable electronic structure and high conductivity. This review outlines the progress in the application of TMP catalysts in NO₃RR. The reaction mechanisms of introducing phosphorus to regulate the d-band center of the active metal for optimizing the reaction pathways are discussed. The key synthesis methods including gas-solid/solid-state reactions, liquid-phase synthesis and electrodeposition are showcased, along with their regulatory effects on the morphology of the catalysts. Based on the performance analysis of various TMP catalysts, such as Fe, Co, Ni, and Cu for NO₃RR, strategies for enhancing the ammonia yield rate and Faradaic efficiency through element doping and interface engineering are explored. Finally, the challenges in constructing stable and high-performance TMP catalysts and future development directions are depicted.

A comprehensive investigation of catalytic phenomena using a catalyst with well-defined structures represents a fundamental research strategy in catalytic chemistry. Carbon-based single-atom catalysts, particularly single-atom metal nitrogen-doped carbon (SA-M-NC) materials, have emerged as ideal model systems for mechanistic studies due to their isolated, adjustable, and uniform active sites, along with their outstanding performances across a wide range of catalytic reactions. Given that all metal atoms in SA-M-NC are immobilized and coordinatively saturated, even minor modifications to the coordination environment can lead to significant changes in catalytic behavior. Consequently, structure-activity relationship studies centered on the “coordination environment-performance” correlation have become a central focus in this field. This review summarizes the prevailing configurations dominated by planar four-coordination geometries, as well as a variety of emerging coordination structures, and offers perspectives on the future design and development of advanced coordination architectures in SA-M-NC materials.

This review summarizes recent advances in oxygen evolution reaction (OER) catalysts for anion exchange membrane water electrolysis (AEMWE). It begins by outlining the advantages of AEMWE for clean hydrogen production and the kinetic limitations imposed by the OER. The review systematically introduces OER reaction mechanisms, key performance parameters, and the latest developments in various catalyst materials. It focuses on the advantages, disadvantages, and performance optimization strategies of precious metal-based catalysts, iron-group metal-based catalysts, high-entropy materials, and metal-organic frameworks (MOFs), alongside their catalytic behavior in alkaline environments. The article further explores the underlying mechanisms of the catalytic process from a chemical principles perspective, covering aspects like interfacial water structure, hydrogen-bond networks, ionic double-layer effects, and the dynamic reconstruction of active sites. Finally, it summarizes the main challenges currently facing AEMWE technology. The review concludes with an outlook on future research directions, emphasizing the importance of interdisciplinary approaches combining theoretical computation, in-situ characterization, and machine learning to design high-performance, low-cost, and longlife catalysts. This is crucial for advancing AEMWE towards large-scale commercial application and supporting the development of a green hydrogen economy.

Developing transition metal-based catalysts with high activity and long-term stability has garnered extensive attention for hydrogen evolution reaction (HER). Here, a Co(OH)F nanorod catalyst with a novel CoP/Co(OH)F heterostructure is developed through a simple hydrothermal method and subsequent phosphorization. Notably, the CoP/Co(OH)F shows excellent HER performance, including a low overpotential of 83 mV at 10 mA/cm² and a Tafel slope of 43 mV/dec. Moreover, it also displays outstanding stability for 400 h at a current density of 50 mA/cm². Further analysis reveals that the construction of CoP and Co(OH)F heterojunction interface promotes the electron transfer and further optimizes the adsorption energy of reaction intermediates during HER process. This work provides a new insight to design and construct high-performance heterostructure catalysts for HER.

Improving the performance of Pt-based catalysts in the alkaline hydrogen evolution reaction (HER) still represents a key challenge in this research area. To construct strong metal-support interaction (MSI) is conducive to boosting the performance of Pt catalysts. Herein, the N-doped carbon nanotubes (NCNTs) and defective carbon nanotubes (DCNTs) were synthesized via thermal annealing at two calcination temperatures, and then served as the supports. Compared with the N groups, the defective sites more effectively trapped Pt nanoparticles (NPs) uniformly and firmly due to the stronger MSI. Moreover, Pt dispersion and coordination were regulated by varying the density of defective sites in CNTs. The as-synthesized Pt/DCNT-4.5 showed excellent activity for HER in alkaline media with an overpotential of 17 mV at 10 mA/cm², presenting a greatly enhanced mass activity, intrinsic activity and stability than the Pt/NCNT, and even the commercial Pt/C catalyst. The highly defective nature of the DCNT support endowed the Pt/DCNT-4.5 catalyst with strong metal-support connection that effectively hindered the agglomeration and detachment of Pt NPs, while optimizing its electronic structure. This work provides a novel approach for designing low-Pt, high-performance HER electrocatalysts.

Rational tuning electronic configuration of CoO is important for accelerating sluggish oxygen evolution reaction (OER) kinetics. This work reports a simultaneous incorporation of highly electronegative fluorine (F) and high-valence molybdenum (Mo) into CoO nanoneedles (denoted as FMo-CoO). The dual-doping strategy boosts Co³⁺ content and compressive strain, which strengthens Co—O bond covalency and enables a lattice-oxygen-mediated (LOM) pathway during OER catalysis. Concurrently, the nanoneedle morphology coupled with F/Mo co-doping synergistically enhances surface properties, granting FMo-CoO exceptional superhydrophilicity and superaerophobicity. As a result, FMo-CoO achieves outstanding OER performance in alkaline media, requiring only overpotential of 287 mV at 10 mA/cm². This work provides a novel method to boost the OER performance of CoO by anion and cation ions doping.

Developing ruthenium-based catalysts with high activity and long-term stability is crucial for sustaining efficient oxygen evolution reactions (OER) under acidic conditions. Here, we develop a ruthenium-titanium-tin oxide (RuO₂/TiSnO_x) electrocatalyst featuring a rationally engineered ternary heterostructure composed of RuO₂, TiO₂, and SnO₂ phases with well-defined interfaces. Such a unique architecture establishes a multidirectional electron transport network, which accelerates electron delivery to Ru active sites and mitigates local charge accumulation, thereby suppressing overoxidation and dissolution of Ru under acidic conditions. Structural and spectroscopic characterizations confirm the formation of coherent heterointerfaces, which reconstruct the coordination environment of Ru, thereby favoring optimal adsorption of OER intermediates. Benefiting from synergistic effects, the RuO₂/TiSnO_x catalyst achieves a remarkably low overpotential of 187 mV at 10 mA/cm² in 0.5 mol/L H₂SO₄ and maintains stable operation for 500 h, outperforming most previous Ru-based catalysts. This study demonstrates that ternary heterostructure engineering provides an effective pathway to balance activity and stability in Ru-based acidic OER catalysts, advancing the practical application in proton exchange membrane water electrolysis (PEMWE) systems for green hydrogen production.

Selective producing CH₄ by CO₂ electroreduction remains challenging, primarily hindered by the complexity of reduction products, sluggish protonation kinetics, and competitive hydrogen evolution reaction. Herein, we developed a silica-copper composite catalyst (CuO/SiO₂), where CuO nanoparticles are dispersed on the hydroxyl-functionalized SiO₂ nanosheet. The hydroxyl-functionalized SiO₂ support promotes the formation and transfer of interfacial reactive hydrogen species, lowers the energy barrier for the reduction of CO₂ to CH₄ by stabilizing *COOH, *CO, and *H intermediates. Meanwhile, it favors the hydrogenation of *CHO over C—C coupling between C1 intermediates, thereby shifting product selectivity from multi-carbon products towards CH₄. As a result, CuO/SiO₂ catalyst delivers high CH₄ selectivity over a broad current density range of 0.2–0.9 A/cm², with a peak Faradaic efficiency of 66.2% at 0.6 A/cm². This work demonstrates an effective interfacial engineering strategy for enhancing the selectivity of CO₂-to-CH₄ conversion.

Biomass conversion to building blocks powered by renewable electricity offers a promising route toward low-carbon plastics, as exemplified by the electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). However, this field is limited by a scalable electrocatalyst that can be operated at a large current. Here, we report a facile and scalable Cu-Co bimetal oxide (Cu-CoO_x) electrocatalyst for efficient HMF oxidation. Comprehensive studies reveal that Cu promotes hydroxyl adsorption to form Co(OH)₂ and converts to CoO_x(OH)_yvia electrooxidation. The Cu-CoO_x catalyst was evaluated in a continuous-flow reactor with 200 cm² of electrode area, achieving high Faradaic efficiency (92.49%) and selectivity (ca. 89%) toward FDCA at large operation currents (40–200 A). Moreover, this reactor was operated at 100 A for more than 100 h, reaching high single-pass conversion efficiency (96.5%) and FDCA selectivity (95.5%). This work provides a foundation for the development of stable and large-area electrodes to enable scalable FDCA electrosynthesis.

Covalent organic frameworks (COFs) have emerged as promising photocatalysts due to their designable pore structures, high surface areas, and tunable electronic properties. However, their practical applications are often hindered by inherent limitations, such as high exciton binding energy, poor charge carrier mobility, and sluggish interfacial reaction kinetics. Recently, local microenvironment regulation has proven to be an effective strategy to enhance the photocatalytic performance of COFs. This review comprehensively summarizes various regulation approaches, including element doping, polar functional group modulation, pore size and structure engineering, structure regulation, molecular structure fabrication, linkage regulation, post-synthetic ionic functionalization, chemical bond regulation, and layer-stacking strategy. These methods enable precise control over the electronic structure, pore polarity, and active-site microenvironment of COFs, thereby significantly improving the photogenerated charge separation, reactant adsorption, and catalytic conversion efficiency. This review highlights the successful application of these strategies in photocatalytic hydrogen evolution, CO₂ reduction, and H₂O₂ production. It concludes with perspectives on future challenges in green synthesis, multi-scale microenvironment engineering, mechanistic understanding, and device integration for sustainable solar-to-chemical energy conversion.

Covalent organic frameworks (COFs) based on pyrene (Py) building blocks have emerged as a promising class of photocatalysts for solar-to-chemical conversion. This review comprehensively summarizes recent advances in the design and application of Py-COFs for two critical reactions: photocatalytic hydrogen evolution and hydrogen peroxide synthesis. We primarily highlight the various functionalized Py monomers for constructing Py-COF photocatalysts. The structural modulation of Py-COFs at multiple levels is followed to enhance their photocatalytic performance. The molecular engineering strategies, such as donor-acceptor construction, heteroatom doping, and linkage modulation, are employed to precisely tailor the optoelectronic properties, band structures, charge separation efficiency, and surface reaction pathways. The synergistic effects of framework-level structural innovations (e.g., dimensionality control, pore engineering), metal doping, and heterojunction construction are discussed for their roles in optimizing mass transport, active site exposure, and interfacial charge dynamics of the solar-to-chemical reaction. A systematic analysis of structure-performance relationships reveals that synergistic integration of multiple design principles is key to overcoming inherent limitations of organic semiconductors. Finally, current challenges and future perspectives are outlined, providing a roadmap for the development of high-performance, stable, and scalable Py-COF photocatalysts to meet the growing demands for sustainable energy and green chemical synthesis.

Carbon-supported transition metal single-atom catalysts (TM-SACs) demonstrate exceptional promise for the electrochemical oxygen reduction reaction (ORR). Here, we carry out density functional theory (DFT) calculations and reveal a linear correlation between the adsorption free energy of the key intermediate OH (ΔG_OH) and the TM-OH bond strength. The TM-OH bond strength is governed by the symmetry-dependent contributions of different d orbitals to the bonding and antibonding interactions at the active site. The local in-plane coordination environment modulates the energy levels of the d_xy and $d_{x^2-y^2}$ orbitals, resulting in the occupancy variation of the out-of-plane d orbitals (d_xz, d_yz, and $d_{z^2}$). Therefore, we introduce a descriptor ($\theta_{\rm{OH}}=\theta_{d_{xz}}+\theta_{d_{yz}}+|1-\theta_{d_{z^2}}|$, $\theta_{\rm{d_{xz}}}$, $\theta_{\rm{d_{yz}}}$ and $\theta_{d_{z^2}}$ indicating the occupancy of d_xz, d_yz, and $d_{z^2}$ orbitals in the coordinated TM) to predict the catalytic performance of TM-Z_x SACs (TM=3d transition metals, Z=N, C, O, x=3, 4, 5) towards ORR. Furthermore, we develop a generalized descriptor φ, which only depends on the geometric and elemental characteristics of the TM, coordinating atoms (Z) and adsorbates. The descriptor can capture both the electronic properties and catalytic activity of TM-Z_x-C SACs without the need for additional calculations. Our findings provide an efficient and convenient strategy for optimizing catalytic performance through tailored geometric and electronic configurations.

Chiral crystalline porous materials demonstrate significant potential in enantiomeric separation, asymmetric catalysis, circularly polarized luminescence (CPL), and chiral sensing. However, constructing stable porous molecular crystals (PMCs) with well-defined chirality and permanent porosity remains challenging. Herein, we report the successful preparation of a pair of homochiral porous molecular crystals (PMCs), denoted as (R)-/(S)-BINAM-PMC, via ionic self-assembly of axially chiral 1,1′-binaphthyl-2,2′-diamine (BINAM) as a basic building block with 4,4′-biphenyldisulfonic acid (BPDS). The ionic pairs formed between sulfonate anions and ammonium cations assemble into one-dimensional (1D) chains through electrostatic interactions, which further extend into two-dimensional (2D) layered structures and ultimately stack into a three-dimensional (3D) porous framework with 1D channels. The material maintains structural and porous integrity after guest removal, demonstrating excellent stability and permanent porosity. Furthermore, circular dichroism (CD) spectroscopy confirms its distinct chiral nature. This work provides valuable insights for the design and fabrication of stable chiral crystalline porous materials.

Developing green and efficient methods to acquire lignocellulose-based chemicals with high added value is beneficial for facilitating green chemistry and sustainable development. The goal of this study is to demonstrate that bio-based cresol, a noteworthy high-value chemical, is able to be directionally prepared from lignocellulosic biomass. This new controllable transformation was materialized by uniting catalytic pyrolysis of lignocellulose to toluene intermediate and catalytic hydroxylation of toluene intermediate to bio-based cresol. This work also developed a novel highly active magnetic catalyst [NiFe₂O₄@Biochar(HTR)], which was synthesized via hydrothermal-reduction (HTR) method using ethylene glycol reductant. The NiFe₂O₄@Biochar(HTR) catalyst exhibited high cresol selectivity (80.2%) and high cresol yield (50.7%) in the synthesis process of cresol. It was found that introducing biochar support into Ni-Fe composite metal oxide catalyst enhanced hydroxyl radical formation and bio-based cresol synthesis. Based on catalyst characterizations and hydroxyl radical analysis, presumable reaction mechanism for bio-based cresol synthesis was proposed.

In this work, Bi₂WO₆ nanosheets were grown on the TiO₂ surface via a solvothermal method to construct a Bi₂WO₆/TiO₂ material with S-scheme charge modulation heterojunctional structure. The heterojunctional composites significantly improve the separation and movement of charge carriers produced by increasing photon absorption, broadening the visible light harvesting range, and maintaining the redox potential of charge carriers. We performed a systematic analysis on the crystal structure and morphological characteristics of the material and the interface electronic transfer mechanism as well. The optimal tetracycline (TC) degradation rate of Bi₂WO₆/TiO₂ was 72.2% within 40 min illuminated by a light source of λ>365 nm and at a Bi₂WO₆/TiO₂ molar ratio of 0.1, which was 31.3 times higher than that of TiO₂ and 3.9 times higher than that of Bi₂WO₆. Through the use of liquid chromatograph mass spectrometer (LC-MS) and ecological structure activity relationship (ECOSAR), additional evaluations brought to light: there are two potential ways, in which degradation may occur. In addition, the biological toxicity of the generated intermediate products was checked through ECOSAR analysis. Finally, the S-scheme heterojunction charge transfer mechanism is proposed in detail. We hope that this work will further highlight the way of modulation of the excited charges in Bi₂WO₆/TiO₂ nanocomposite to accelerate photocatalysis.

A novel Zn-based luminescent coordination polymer [Zn(phen)(H₂O)]₂[L]·2H₂O (1), [H₄L=(E)-5,5′-(diazene-1,2-diyl) diisophthalic acid] was synthesized via a solvothermal reaction, which has a three-dimensional supramolecular structure. Compound 1 exhibits good chemical and thermal stability, and can effectively detect nitroaromatic explosives (NACs) via a fluorescence quenching effect. Especially for 2,4,6-trinitrophenol, compound 1 has demonstrated very high sensitivity (K_SV=1.9×10⁴ L/mol), low detection limit (LOD=9.6×10⁻⁶ mol/L) and good anti-interference ability. Additionally, Compound 1 also exhibits good selective recognition of Fe³⁺ with excellent anti-interference performance and reusability. Through UV-visible spectroscopy and density functional theory calculations, the fluorescence quenching mechanisms of compound 1 for various analytes are discussed in detail. Based on the above excellent properties of compound 1, it has great application potential in water quality monitoring.

Antibiotics have gained significant attention as emerging marine pollutants, with their trace-level detection in high-salinity environments being a key analytical challenge. This study developed a two-stage desalination technique that integrates ultrasound-assisted liquid-liquid extraction (US-LLE) with self-desalting droplet spray ionization (SD-DSI) for rapid mass spectrometric analysis of antibiotics. Key influencing factors, including extraction and redissolution solvent types and volumes, extraction time, and dispensing volume, were systematically optimized. Under optimal conditions, the US-LLE-SD-DSI method successfully determined multiple classes of antibiotics in simulated seawater. Clarithromycin and azithromycin exhibited linear ranges of 50–1000 ng/mL, with detection limits of 5.9 and 14.9 ng/mL, respectively, and relative standard deviations below 18.5%. Moreover, the signal intensity for high-salinity samples (3.5%, mass fraction) was enhanced by two orders of magnitude compared to untreated samples (0.35%, mass fraction). Applicability studies demonstrated that the method is effective not only for high-salinity samples but also for salt-free/low-salinity and hard water samples. The established approach provides a streamlined analytical solution for the rapid and sensitive determination of antibiotics in high-salinity seawater.

Cu/zeolite catalysts have attracted considerable attention for cold-start applications; however, their efficiency in propylene adsorption remains limited. To address this challenge, Cu/ZSM-5 catalysts with enhanced metal-support interactions were successfully constructed via a seed-assisted, template-mediated synthesis method, leading to improved propylene capture and oxidation efficiency. The catalysts were systematically characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), N₂ adsorption-desorption, scanning electron microscope (SEM), transmission electron microscope (TEM), NH₃-TPD, X-ray photoelectron spectroscope (XPS), and in situ infrared spectroscopy to investigate the influence of acid site density and metal-support interactions on propylene adsorption behavior. The results demonstrated that Cu@ZSM-5 catalysts synthesized with different structure-directing agents exhibited distinct acidity profiles and varying strengths of metal-support interaction. Among them, the Cu@ZSM-5-130 sample prepared using the TPAOH template showed a high specific surface area (474 m²/g) and a more optimal acidity balance. It was found that an excessive density of strong acid sites can be detrimental to propylene adsorption and oxidation. The intimately associated Cu species within the zeolite matrix facilitated selective adsorption of hydrocarbons, particularly propylene. In situ infrared spectroscopy further revealed a temperature-dependent oxidation pathway of propylene over the Cu@ZSM-5-TPAOH-130 catalyst, starting with epoxide formation at low temperatures, progressing to partial oxidation products (e.g., acrolein) at intermediate temperatures, and ultimately yielding complete oxidation products, such as CO₂ and H₂O at higher temperatures.

Developing a single platform capable of detecting chemically diverse pollutants in water remains challenging. Herein, we report a water-stable indium-organic framework, JLU-MOF234, constructed from 5-(3-carboxyphenyl)pyridine-2-carboxylic acid, which exhibits strong intrinsic fluorescence and excellent hydrolytic stability. Owing to its rigid coordination architecture and electron-rich conjugated ligand, JLU-MOF234 functions as a highly sensitive, multiresponsive fluorescent sensor capable of detecting Fe³⁺ ions, dichromate anions (Cr₂O₇²⁻), and nitroaromatic explosives in aqueous media. The framework demonstrates pronounced fluorescence quenching toward all three classes of pollutants, with high selectivity and low detection limits. This study highlights JLU-MOF234 as a versatile “all-in-one” luminescent platform for comprehensive environmental monitoring of chemically diverse contaminants.

Solvent-responsive photonic films with programmable deformation are attractive for smart indicators and reconfigurable devices. Here, we present a Janus poly(vinylidene fluoride-cohexafluoropropylene) (PVDF-HFP) inverse opal film composed of a nanoporous upper layer and a dense lower layer, enabling directional bending, solvent-induced plastic deformation with residual-stress-driven reversible configuration change. Exposure to 1,2-dichloroethane induces asymmetric infiltration of the nanostructured pores, generating capillary pressure sufficient to plastically deform the porous layer and produce a characteristic two-step bending behavior. The bending amplitude and accompanying photonic bandgap shift (580–710 nm) are tunable through pore size, solvent volume, and application position. Mechanical and structural analyses support a capillarity-driven plastic deformation mechanism linking nanoscale architecture to macroscopic actuation. The resulting photonic Janus film offers a simple, visually interpretable platform for solvent-triggered shape morphing and exposure indication.

Herein, we report the synthesis of a new anionic metal-organic framework (MOF), [(CH₃)₂NH₂][In(CDIP)]-DMF(1, H₄CDIP=5,5′-carbonyldiisophthalic acid). Compound 1 is constructed from [In(COO)₄]⁻ secondary building units and features a high density of carbonyl functional groups uniformly distributed along the pore surfaces. Benefiting from its anionic framework and functionalized pores, compound 1 exhibits exceptional adsorption performance toward cationic dyes. It achieves a Methylene blue (MLB) removal efficiency of 99.4% within 3 min and an ultrahigh adsorption capacity of 722 mg/g, surpassing most reported indium-based MOFs. Furthermore, compound 1 shows substantial adsorption capacities for larger carcinogenic dyes, including Basic Red 9 (BR9, 119 mg/g) and Basic Violet 14 (BV14, 148 mg/g). Efficient and selective adsorption of these dyes is also realized in mixed-charge dye systems. Kinetic and isotherm analyses reveal that the adsorption process follows a pseudo-second-order kinetic model and fits well with the Langmuir isotherm, indicating monolayer chemisorption. Notably, after three adsorption-desorption cycles, the dye removal efficiency remains above 83%, demonstrating good recyclability. These results highlight compound 1 as a promising adsorbent for the selective removal and separation of cationic dyes from wastewater.

The direct and selective C4—H functionalization of indoles remains a significant synthetic challenge. Addressing this, we disclose a highly efficient Rh(III)-catalyzed C4—H alkenylation of indoles employing gem-difluoromethylene alkynes. This directing group-assisted protocol delivers valuable difluorinated indole derivatives in excellent yields (up to 88%), with a broad substrate scope and exceptional functional group tolerance, providing a practical and versatile route for appealing indole diversification.

The development of effective acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors remains a crucial objective in the treatment of neurodegenerative diseases, including Alzheimer’s disease (AD). In this study, a novel synthetic approach was established to prepare a series of diaryl-substituted tacrine derivatives. Initially, brominated aminobenzonitrile was subjected to Suzuki-Miyaura cross-coupling reactions with various aryl boronic acids to yielding diaryl-substituted aminobenzonitriles at yields of 60%–72%. These intermediates were then cyclized with cyclohexanone and cycloheptanone under Friedländer conditions using BF₃·OEt₂ as a catalyst, affording six- and seven-membered diaryl tacrine analogues in yields of 52%–68%. All synthesized compounds were characterized by NMR, IR, and elemental analysis. The inhibitory activities of these compounds (7–16) against AChE and BChE were evaluated, and several analogs demonstrated potent dual-enzyme inhibition at nanomolar concentrations. Notably, compounds 8 and 13 exhibited half maximal inhibitory concentration (IC₅₀) values of 6.848 and 8.545 nmol/L for BChE, respectively, indicating strong potential as selective cholinesterase inhibitors. The structure-activity relationship (SAR) analysis revealed the influence of aryl substituents on the potency and selectivity of enzyme inhibition. Compared to previously reported tacrine derivatives, the newly synthesized analogs exhibited superior inhibitory profiles, indicating their potential as lead compounds for further development in AD therapeutics.

Molecular surface area and volume are widely used to describe molecular size and are closely related to intermolecular interactions and thermodynamic properties. Conventional geometric models rely on empirical atomic radii, whereas electronic-structure-based definitions provide a more intrinsic description of molecular boundaries but remain computationally demanding. In this work, we define molecular surface area and volume using an isopotential condition of the Kohn-Sham (KS) one-electron potential and construct a machine learning model to accelerate their evaluation. Reference data were generated from three-dimensional KS potential grids and followed by geometric integration. SchNet was then trained to learn the relationship between molecular structure and the corresponding KS-defined size descriptors. The model achieves high predictive accuracy, with R² values exceeding 0.9900 for surface area and 0.9800 for volume on the test set. The predicted descriptors exhibit strong linear correlations with van der Waals surface area and volume, and display clear relationships with experimental boiling points. These results indicate that the proposed size descriptors retain electronic-structure information while being efficiently predictable from molecular geometry. This work demonstrates that electronic-structure-based molecular size definitions can be combined with machine learning to provide accurate and computationally scalable descriptors for molecular modeling and property prediction.

This work revealed for the first time that SnO@SnO₂ heterojunction (SnO_x, 1<x<2) could act as a novel and powerful electrochemiluminescence (ECL) co-reactant. Heterojunction-containing SnO@SnO₂ nanostructures (ca. 20 nm) capped with mercaptosuccinic acid (MSA) were uniformly produced by MSA-etching tin nanoparticles, and could be spontaneously self-assembled into large-sized (ca. 200 nm), well-dispersed, uniform, and spherical nanoparticles (SnO@SnO₂-MSA SANs). The synthesized SnO@SnO₂-MSA SANs could act as a highly efficient co-reactant for the Ru(bpy)₃²⁺ ECL system, outperforming the conventional co-reactant tri-n-propylamine (TPrA). It was revealed that the high co-reactant activity of SnO@SnO₂ did not originate from SnO or SnO₂ alone, but from the heterojunction of SnO@SnO₂ (i.e., SnO_x, 1<x<2). The SnO_x heterojunction acted as a strong co-reactant, initiating highly energetic electron-transfer with the electrogenerated Ru(bpy)₃³⁺ and emitting strong ECL. Utilizing the abundant negative surface charges of SnO@SnO₂-MSA SANs, Ru(bpy)₃²⁺ complexes were successfully loaded via electrostatic adsorption to construct self-enhanced ECL nanocomposites, i.e., SnO@SnO₂-MSA SANs@Ru(bpy)₃²⁺. The composites exhibited highly efficient anodic ECL emission peaking at 618 nm without requiring any exogenous species. The nanoscale integration of Ru(bpy)₃²⁺ luminophores and SnO@SnO₂-MSA SAN co-reactants shortens the electron-transfer pathway and thus improves the interfacial ECL reaction efficiency.