Lattice oxygen (OL) of metal oxides plays a critical role in catalytic reactions. In this study, we investigated two representative cubic metal oxides, cobalt tetroxide (Co3O4) and cuprous oxide (Cu2O), to propose a "block" mechanism involving OL in peroxymonosulfate (PMS) activation during the Fenton-like reaction through density functional theory simulation. That is, PMS molecules are preferentially adsorbed onto the surface with lower density of OL. To elucidate this mechanism, model catalysts with OL-enriched (11 1) facets in an octahedral morphology and materials with OL-deficient (100) facets in cubic morphology were synthesized. During the bisphenol A degradation experiments, the catalytic activity across all classes of metal oxides exhibits a strong linear correlation with the exposure of the (100) facet. Remarkably, the reaction rate constant of Co3O4 increased by over 16-fold upon transitioning from octahedral to cubic morphology. Motivated by the structural influence of different catalysts on PMS activation, we systematically evaluated both the intrinsic material architecture including work function (WF) and texture coefficient (TC) and its impact on PMS adsorption (Eads). A descriptor of chi comprised with above three parameters was built with the equation of & sum;ni=1[WF*TC*Eabs]alpha ii . This chi can describe the structure-activity relationship accurately, that exhibits a strong linear correlation with the normalized reaction rate constant. This work establishes a fundamental mechanistic understanding for designing efficient metal oxides in Fenton-like water treatment technologies.

Developing efficient solid waste-based catalysts for Fenton-like reactions is of great significance in wastewater treatment. Herein, a series of iron-copper bimetallic sulfides with multi-prismatic microstructures were facilely synthesized using wasted batteries as the metal precursors. With carbamazepine (CBZ) as the model pollutant and peroxymonosulfate (PMS) as the oxidant, the optimized Fe/Cu@S-1:1 catalyst can degrade CBZ to below the limit of quantification within 30 min and exhibit the wide pH range tolerance. The excellent catalytic activity is ascribed to the synergistic interaction between Fe and Cu sites, the abundance of surface Cu(I) and Fe(II) active sites, and the presence of highly reductive sulfur species that help maintain the metals with low-valent states during PMS activation. According to the quenching experiments, the main reactive oxidation species (ROSs) in Fe/Cu@S-1:1/PMS system are determined to be center dot OH, O2 center dot-, and 1O2. This study provides a novel strategy for designing high performance iron-copper bimetallic sulfide catalysts for Fenton-like reactions, and giving new insights into the resource utilization of wasted batteries for advanced wastewater treatment.

Traditional methods for treating Cr(VI)-containing wastewater often encounter issues such as high energy consumption, susceptibility to secondary pollution and limited treatment efficiency. In contrast, photocatalytic technology harnesses solar energy to efficiently reduce Cr(VI) to less toxic Cr(III) under mild conditions, offering advantages including operational simplicity and environmental friendliness, thereby providing a superior alternative. This study proposes a dual MOF precursor strategy to synthesise Cd-ZIF@NH2-MIL-68 composite materials, which undergo further sulphurisation to successfully construct a CdS/In2S3 type-II heterojunction photocatalyst with a hollow structure. This material exhibits a larger specific surface area, increased exposure of active sites and abundant heterojunction interfaces. This heterojunction achieves an ultrafast, 99.26% removal of Cr(VI) within only 18 min under LED illumination, exhibiting outstanding stability with 88.10% activity retention after five cycles. Systematic characterization, photoelectrochemical tests and density functional theory (DFT) calculations collectively confirm that the successful band engineering in CdS/In2S3 induces the formation of a type-II heterojunction, thereby significantly facilitating the efficient separation and migration of photogenerated charges. The combination of radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy identifies photogenerated electrons (e-) and superoxide radicals (·O2-) as the predominant reactive species. This work provides new insights for designing highly efficient MOFs-derived heterojunction photocatalysts for the rapid remediation of Cr(VI) pollution.

Semiconductor photocatalysis offers a promising approach to addressing global energy shortages and environmental pollution. Among the strategies developed, Z-scheme heterojunction photocatalysts have attracted extensive research interest in the field due to their ability to mimic the charge transfer pathway of natural photosynthetic systems. Compared with conventional Type-II heterojunctions, Z-scheme heterojunctions achieve selective recombination of low-energy carriers at the interface while preserving strongly reductive conduction band electrons and strongly oxidative valence band holes, thereby offering the potential to combine strong redox driving force with efficient charge separation, although the mechanistic evidence supporting this combination varies considerably in rigor across the systems reviewed here. This review systematically examines recent advances in Z-scheme heterojunction photocatalysts, covering the fundamental principles of semiconductor photocatalysis and the Z-scheme charge transfer mechanism, and classifying the systems into liquid-phase mediator, all-solid-state, and direct Z-scheme types. Subsequently, the design strategies of Z-scheme heterojunctions are systematically summarized from five aspects: band structure regulation, interface engineering, defect and doping control, microstructure design, and conductive mediator construction. The review then focuses on the research progress of Z-scheme heterojunctions in three representative applications: photocatalytic degradation of organic pollutants, photocatalytic water splitting for hydrogen production, and photocatalytic CO2 reduction. Finally, the current challenges and future research directions are summarized and discussed.

With the increasing environmental issues caused by sulfur compound emissions from fossil fuels, the development of green and efficient desulfurization technologies has become a research hotspot. Deep eutectic solvents (DESs), as emerging low-cost, customizable green solvents, show great potential in fuel desulfurization. This article provides an in-depth analysis of the desulfurization mechanism of DESs, including hydrogen bonding, enhanced pi-pi and CH-pi interactions, and synergistic effects of metal ions 12. In addition, oxidation-extraction coupling strategies and process enhancement techniques such as ultrasonic-assisted extraction and microchannel mass transfer further improve desulfurization efficiency. In addition, oxidation-extraction coupling strategies and process enhancement techniques (such as ultrasonic-assisted extraction and microchannel mass transfer) further improve desulfurization efficiency. Overall, DES has broad application prospects in fuel extraction desulfurization and is expected to serve as an alternative or complementary method to hydrodesulfurization technology.

A metal-free Cl/N co-doped defect-rich carbon electrocatalyst (MF-ClNC) was synthesized by salt-assisted two-step pyrolysis. Doping and defect sites synergistically modulate the electronic structure and boost the oxygen reduction reaction (ORR) process. MF-ClNC exhibits exceptional ORR performance in both alkaline electrolyte (half-wave potential 0.91 V) and natural seawater (0.78 V), exceeding commercial Pt/C and most reported catalysts. Our work highlights the potential of coupling doping and defects in carbon catalysts for electrochemical applications.

Oxide-derived copper (OD-Cu) is a promising catalyst for the efficient production of C2+ products in the electrocatalytic CO2 reduction reaction. However, the reconstruction processes for the formation of OD-Cu are poorly understood, and the effects of catalyst precursors on performance are not yet clear, which hinder the rational construction of efficient catalysts for the production of C2+ products. In this work, we propose a strategy of "framework-dissolution" to introduce inert elements to construct different framework structures for Cu-O geometrical coordination modulation. In situ X-ray diffraction and Raman characterizations reveal the effect of different Cu-O geometric coordination on the OD-Cu reconstruction process and the regulation mechanism of the crystal facets. The results demonstrate that OD-Cu exhibits different (200)/(111) facet ratios, with the OD-Cu-t (200) facet dominating. The catalytic performance of OD-Cu-t dominated by Cu (200) reaches 75.1% Faradaic efficiency (FEC2+) with a partial current density of -187.8 mA cm(-2). Theoretical calculations indicate that the OD-Cu-t derived from tetrahedra Cu-O geometric coordination is dominated by the (200) facet, which is favorable to promote the production of C2+ in CO2RR. This work not only fundamentally reveals the structural transformation of electrocatalysts with different Cu-O geometric coordination during the reaction process, but also contributes to the rational design of high-efficiency and low-cost catalysts.

Photoinduced [2+2] cycloaddition of biomass-derived cycloolefin is a promising approach to synthesize high-energy bio-fuels, however, the conversion efficiency and selectivity are still low. Herein, we provide an acid-promoted photocycloaddition approach to synthesize a new kind of spiral fuel from biomass-derived cyclohexanone (CHOE) and camphene (CPE). Brønsted acids show higher catalytic activity than Lewis acids, and acetic acid (HOAc) possesses the best catalytic performance, with CHOE conversion up to 99.1%. Meanwhile, the HOAc-catalytic effect has been confirmed for [2+2] photocycloaddition of other biomass-derived ketenes and olefins. The catalytic mechanism and dynamics had been investigated, and showed that HOAc can bond with C=O groups of CHOE to form H-CHOE complex, which leads to higher light adsorption and longer triplet lifetime. Meanwhile, H-CHOE complex reduces the energy gap between CHOE LUMO and CPE HOMO, shortens the distance of ring-forming atoms, and then decreases the energy barrier (from 103.3 kcal/mol to 95.8 kcal/mol) of rate-limiting step. After hydrodeoxygenation, the targeted bio-spiral fuel shows high density of 0.992 g/cm3, high neat heat of combustion of 41.89 MJ/L, low kinetic viscosity of 5.69 mm2/s at 20°C, which is very promising to serve as high-performance aerospace fuel.

Bearings are an essential part of rotating machinery, but they frequently fail, particularly in situations requiring high-strength load bearing and fast rotation speed. This research suggests a unique strategy based on acoustic signals to solve the issues of low accuracy and limited resilience in the current bearing failure detection methods. A lightweight fault diagnosis network, MS-GhostNet V3, is designed to enhance the performance and efficiency of bearing fault detection. Firstly, the acoustic signals produced by rotating machinery are collected using a linear microphone array, capturing the spatial distribution and phase characteristics of the acoustic signal. To improve fault characteristic expressiveness, the time-frequency domain feature map of the acoustic signal is obtained using the short-time Fourier transform. Then the MS-GhostNet V3 network is used to realize bearing fault diagnosis. MS-GhostNet V3 is composed of multi-scale convolution fusion module (MCFM), ghost bottleneck module (GBNM) and classifier. To obtain multi-scale information, the multi-scale convolution parallel structure creates the MCFM. The GBNM, integrating the ghost module with the spatial and channel synergistic attention module, facilitates a more comprehensive representation of fault characteristics across both spatial and channel dimensions. Consequently, this enhances defect identification precision. According to experimental results, the suggested approach yields accuracies of 96.19% and 96.88% on both private and publicly available datasets. These outcomes satisfy the requirements for real-time defect detection and lightweight operation. And compared to classical methods, it exhibits superior fault diagnosis performance, with enhanced accuracy and robustness under noise interference. The code is available at: https://github.com/xgli411/MS-GhostNet-V3.

Photocatalysis is an important means of realizing the efficient use of solar energy and alleviating energy consumption and environmental pollution. This work used a simple solvothermal synthesis method to prepare a series of zinc sulfide/sulfur-doped polyimide (ZnS/SPI) direct Z-type heterostructured photocatalysts. ZnS/SPI heterostructured photocatalysts have better photogenerated electron-hole pairs separation and wider visible light absorption region. The effect of ZnS on the properties of ZnS/SPI composites, such as morphology, structure, and optoelectronic properties, was systematically investigated by a series of characterization tests. These results showed that the photocatalytic activity of the ZnS/SPI composite was significantly improved compared with SPI. The 10ZnS/SPI composite exhibited the highest photocatalytic hydrogen production rate under full irradiation (216.9 µmol/g/h), which was about 2.8 times higher than that of SPI (76.6 µmol/g/h). Moreover, it has a high stability over a long period in the photocatalytic process. The enhanced photocatalytic performance of the ZnS/SPI heterojunction is mainly due to the close contact between the ZnS nanoparticles and the SPI interface, which improves the charge separation and reduces the complexation rate of electron-hole. This work shows that the formation of ZnS/SPI composites Z-type heterojunction can effectively enhance the activity of polymer photocatalysts.

Nitrogen doped carbon materials have great potential in the peroxymonosulfate based advanced oxidation processes due to their high efficiency. However, because of the limitation of prepared method, the doped N species are usually uncontrollable. In this work, a series of metal-free N-doped carbon materials are synthesized by chemical vapor deposition (CVD) with a CaO template and through regulating the deposition temperature we achieve the gradient control of the edged-N species. Taken phenol as the pollutant probe, the catalytic performances of N-doped carbon material are investigated, and 700 degrees C is determined to be the optimal deposition temperature for carbon material with a reaction rate constant of 0.335 min-1. After the analysis of kinetics and the N species, we demonstrate that the content of pyrrolic N has an exponential relationship with the activity. Radicals quenching experiments, electron paramagnetic resonance and electrochemical test are also employed to verify that O2 center dot-, 1O2, and direct electron transfer are the dominated reactive oxidation species rather than typic hydroxyl and sulfate radicals. Overall,this doped strategy through CVD give a new insight of controlling doped species in carbon materials preparation.

In this study, a series of Fe-based materials are facilely synthesized using MIL-88A and melamine as precursors. Changing the mass ratio of melamine and MIL-88A could tune the coating layers of generated zero-valent iron (Fe-0) particles from Fe3C to Fe3N facilely. Compared to Fe/Fe3N@NC sample, Fe/Fe3C@NC exhibits better catalytic activity and stability to degrade carbamazepine (CBZ) with peroxymonosulfate (PMS) as oxidant. Free radical quenching tests, open-circuit potential (OCP) test and electron paramagnetic resonance spectra (EPR) prove that hydroxyl radicals ((OH)-O-center dot) and superoxide radical (O-2(center dot-)) are dominant reactive oxygen species (ROSs) with Fe/Fe3C@NC sample. For Fe/Fe3N@NC sample, the main ROSs are changed into sulfate radicals (SO4 center dot-) and high valent iron-oxo (Fe (IV)=O) species. In addition, the better conductivity of Fe3C is beneficial for the electron transfer from Fe-0 to the Fe3C, thus could keep the activity of the surface sites and obtain better stability. DFT calculation reveals the better adsorption and activation ability of Fe3C than Fe3N. Moreover, PMS can also be adsorbed on the Fe sites of Fe3N with shorter Fe-O bonds and longer S-O bonds than on Fe3C, the Fe (IV)=O is thus present in the Fe/Fe3N@NC/PMS system. This study provides a novel strategy for the development of highly active Fe-based materials for Fenton-like reactions and thus could promote their real application.

Solar-driven conversion of renewable biomass resources into high-density hydrocarbon fuels can effectively realize biomass valorization and renewable energy conversion. In this work, an efficient self-sensitized [2 + 2] photocycloaddition process is explored to develop highly strained fuel with high yield using norbornene and biomass-derived cyclohexenone as feedstocks. The enhancement mechanism is revealed by phosphorescent measurement and theoretical calculation, and a reasonable reaction path for self-sensitized [2 + 2] co-cycloaddition is proposed. When using methanol as solvent, the apparent activation energy of co-cycloaddition is 21.37 W/mol, which is lower than that of self-cycloaddition (31.57 W/mol). Importantly, the jet-fuel-range highly strained fuel has high density (0.986 g/cm3) and high volumetric net heat of combustion (41.14 MJ/L), which are 5.34% and 4.39% higher than those of JP-10, respectively. This work proposes a green and effective pathway for the preparation of high-performance hydrocarbon fuel with polycyclic-asymmetric structure.

Homojunction is a viable alternative strategy to realize excellent charge separation for enhancing photoelectrocatalytic performance. However, the feasible regulation of the homojunction interface remains challenging. Herein, a ZnO n -p homojunction with the piezotronic effect is constructed via an in -situ solvothermal method for enhancing photoelectrocatalytic activity. ZnO nanorods are transformed from n -type to p -type ZnO nanoparticles with zinc vacancies, leading to the n -p homojunction. The optimal NPZ-36 exhibits a superior photocurrent density of 1.56 mA/cm 2 at 1.23 V vs. RHE and a high incident photon to current conversion efficiency of 75 % at 360 nm. Impressively, with the merits of inherent piezoelectric and photocatalytic properties of wurtzite ZnO, the piezoelectric -enhanced photoelectrochemical activity originates from the simultaneous promotion of bulk charge transfer and interfacial charge separation in ZnO n -p homojunction. The photocurrent density of NPZ-36 -900 can reach to 2.02 mA/cm 2 under the stirring rate of 900 rpm, which is 2.1 times higher than that of pure ZnO photoanode.

The periodical distribution of N and C atoms in the carbon nitride skeleton results in intrinsically insuf-ficient light absorption and serious carrier recombination. Herein, an efficient two-step cystine-mediated strategy was developed to alter the structure symmetry of C3N4 via the introduction of alkyl groups and nitrogen vacancies. The experimental analysis and theoretical calculation confirm that the formation of alkyl groups and nitrogen vacancies can modulate band structure and activate n -1t* electron transition. Especially, the charge density in CN-25CYS is redistributed with spatial separation of oxidation and reduction sites, suppressing photogenerated charge recombination effectively. Therefore, the distorted carbon nitride (CN-25CYS) exhibits 9.6-times and 15.6-times higher photoreaction rates in hydrogen pro-duction and RhB degradation than the pristine one (CN-0CYS), respectively.(c) 2023 Elsevier Inc. All rights reserved.

Direct air capture (DAC) can be used to decrease the CO2 concentration in the atmosphere, but this requires substantial energy consumption. If residual waste carbon (in the form of bicarbonate solution) from DAC can be directly reused, it might present a novel method for overcoming the aforementioned challenges. Electrochemical CN coupling methods for synthesizing urea have garnered considerable attention for waste carbon utilization, but the carbon source is high-purity CO2. No research has been conducted regarding the application of bicarbonate solution as the carbon source. This study proposes a proof-of-concept electrochemical CN coupling process for synthesizing urea using bicarbonate solution from DAC as the carbon source and nitrate from wastewater as the nitrogen source. These results confirmed the feasibility of synthesizing urea using a three-electrode system employing TF and CuInS2/TF as the working electrodes via potentiostatic electrolysis. Under the optimal conditions (initial pH 5.0 and applied potential of -1.3 V vs. Ag/AgCl), the urea yield after 2 h of electrolysis reached 3017.2 μg h-1 mgcat.-1 and an average Faradaic efficiency of 19.6 %. The in-situ attenuated total reflection surface-enhanced infrared absorption spectroscopy indicated a gradual increase in the intensity of the -CONH bond signal on the surface of the CuInS2/TF electrode as the reaction progressed. This implied that this bond may be a key chemical group in this process. The density functional theory calculations demonstrated that *CONH was a pivotal intermediate during CN coupling, and a two-step CN coupling reaction path was proposed. *NH + *CO primarily transformed into *CONH, followed by the conversion reaction of *CONH + *NO to *NOCONH2. This study offers a groundbreaking approach for waste carbon utilization from DAC and holds the potential to furnish technical underpinnings for advancing electrochemical CN coupling methods.

Hydrogen production from electrochemical water splitting has attracted great attention due to its supply to green energy. However, commercial alkaline water electrolysis is energy intensive due to inert and large overpotentials of anodic oxygen evolution reaction (OER). Electro-oxidation of organics is an attractive alternative to the OER. With electro-oxidation of special organic substrates on an active anode, decreased cell voltage of H-2 evolution can be achieved along with the production of value-added products. In this review, we summarize the latest progress on coupled H-2 production with organic electro-oxidation systems. Different organic compounds containing oxygen (alcoholic hydroxyl, aldehydes, ketone), nitrogen, sulfides, and olefin/alkane groups have been selectively oxidized into high value-added products on the anodes, thereby promoting H(2 )evolution on the cathodes. Some complicated coupling reactions, such as the formation of C-C and C-N, are also introduced in the coupling systems. In addition, the challenges and prospects for the future development of this research field are highlighted.

以葡萄糖为碳源、NaNO3为模板和造孔剂,通过高温炭化法以及NH3高温后处理合成了多级孔氮掺杂碳材料NC-X-T[X为NaNO3与葡萄糖的质量比,T为温度(℃)].采用N2吸附-脱附、XRD、XPS、SEM、TEM对NC-X-T的比表面积、孔径分布、晶体结构、化学组成以及形貌进行了表征与测试.以NC-X-T为催化剂、过硫酸氢钾(PMS)为氧化剂,在不同条件下进行了苯酚的降解.结果表明,造孔和掺氮过程的协同可极大提升NC-X-T 的催化性能.0.005 g NC-0.5-800 及质量浓度 1.0 g/L PMS 在 40 min 内可将 100 mL 5.3×10-4 mol/L 苯酚完全降解,反应速率常数高达0.397 min-1,优于大多数金属及非金属催化剂.利用XPS对降解过程中NC-X-T的稳定性进行了研究,证实碳材料的氧化是其失活的主要原因,经过高温无氧处理可以恢复其部分催化活性.

Given a volume-fixed oil-tank, the advanced fuels with high energy density will increase the payload and range of the aircraft. Herein, we synthesized the high-energy-density liquid fuel via catalytic dimerization of norbornene by the acidic zeolites. Importantly, we reveal the relationship between the structural properties (i.e., B/L acid site ratio and porous structure) of acidic zeolites and the conversion and selectivity of dimerization, and demonstrate the mechanism and kinetics of isomerization-dimerization two-step process. Among the investigated catalysts, H beta-25 exhibits the best activity with high norbornene conversion and acceptable dimers selectivity, which is attributed to the synergy effect of appropriate B/L acid site ratio and suitable pore size. After hydrogenation, the obtained fuel has high density (0.978 g/cm(3)) and high volumetric neat heat of combustion (41.49 MJ/L), which are much higher than those of widely used JP-10 fuel. This work provides a promising route to produce high-energy-density fuel for practical application.