二氧化碳在铜氧化膜电极上的光电化学还原

本文研究了CO_2在铜阳极氧化膜电极上的光电化学还原行为,在还原电量小于0.1C时,CH_4 的产率较高;还原电量大于2.0C时,主要还原产物为CH_3OH,还对CH_4的产率随外加电位、还原电量和铜阳极氧化膜制备条件的变化关系进行了研究,并对其还原机理作了初步探讨。

CO_2在p-SiC膜电极上的光电化学还原

近年来,CO_2的光电化学还原引起人们极大的兴趣,已有利用SiC粉末进行CO_2光催化还原的报道。本研究首次利用p-SiC膜光阴极还原CO_2,得到较高的CH_3OH产率。1 实验 在导电玻璃上采用水银光敏化CVD法制得微晶p-SiC膜,电极表面用4.

原位电化学-光还原法制备Pd/BiF3薄膜及其光催化性能

通过电化学-光还原法基于Bi板合成了Pd/BiF3薄膜,探究了不同质量分数的Pd对BiF3薄膜光催化性能的影响。利用X射线衍射仪、扫描电子显微镜、X射线光电子能谱、紫外-可见漫反射光谱对Pd/BiF3薄膜进行了表征分析。以模型污染物即罗丹明B(RhB)为光催化降解对象,考察了Pd/BiF3薄膜的光催化性能。表征结果显示,贵金属Pd均匀分布于BiF3薄膜表面上,当Pd的质量分数为2.0%时,Pd/BiF3薄膜表现出最佳的光催化降解RhB的性能,且光吸收带边发生明显的红移,带隙值由3.70 eV减小为3.03 eV。活性物种捕获实验表明,当Pd的质量分数为2.0%时,在Pd/BiF3薄膜光催化降解RhB的过程中,活性物种发挥的作用由大到小的顺序为羟基自由基(·OH)、超氧自由基(·O2^-)、空穴(h+),并提出了Pd/BiF3薄膜光催化性能的增强机制。

Photoelectrochemical nitrogen reduction:A step toward achieving sustainable ammonia synthesis

Industrial NH3 production mainly employs the well‐known Haber‐Bosch(H‐B)process,which is associated with significant energy consumption and carbon emissions.Photoelectrochemical nitro‐gen reduction reaction(PEC‐NRR)under ambient conditions is considered a promising alternative to the H‐B process and has been attracting increasing attention owing to its associated energy effi‐ciency and environmentally friendly characteristics.The performance of a PEC‐NRR system,such as the NH_(3) yield,selectivity,and stability,is essentially determined by its key component,the photo‐cathode.In this review,the latest progress in the development of photocathode materials employed in PEC‐NRR is evaluated.The fundamental mechanisms and essential features required for the PEC‐NRR are introduced,followed by a discussion of various types of photocathode materials,such as oxides,sulfides,selenides,black silicon,and black phosphorus.In particular,the PEC‐NRR reac‐tion mechanisms associated with these photocathode materials are reviewed in detail.Finally,the present challenges and future opportunities related to the further development of PEC‐NRR are also discussed.This review aims to improve the understanding of PEC‐NRR photocathode materials while also shedding light on the new concepts and significant innovations in this field.

Efficient development of Type-Ⅱ TiO_2 heterojunction using electrochemical approach for an enhanced photoelectrochemical water splitting performance

Type‐II‐heterojunction TiO2nanorod arrays(NAs)are achieved by a combination of reduced and pristine TiO2NAs through a simple electrochemical reduction.The heterojunction‐structured TiO2NAs exhibit an enhanced photo‐efficiency,with respect to those of pristine TiO2NAs and completely reduced black TiO2.The improved efficiency can be attributed to a synergistic effect of two contributions of the partially reduced TiO2NAs.The light absorption is significantly increased,from theUV to the visible spectrum.Moreover,the type II structure leads to enhanced separation and transport of the electrons and charges.The proposed electrochemical approach could be applied to various semiconductors for a control of the band structure and improved photoelectrochemical performance.

Functionalized CVD monolayer graphene for label-free impedimetric biosensing

Recent advances in large area graphene growth have led to many applications in different areas. In the present study, chemical vapor deposited （CVD） monolayer graphene supported on glass substrate electrochemical biosensing applications was examined as electrode material for We report a facile strategy for covalent functionalization of CVD monolayer graphene by electrochemical reduction of carboxyphenyl diazonium salt prepared in situ in acidic aqueous solution. The carboxyphenyl-modified graphene is characterized using Raman spectroscopy, X-ray photoelectron spectroscopy （XPS）, and atomic force microscopy （AFM）, as well as electrochemical impedance spectroscopy （hIS）. We also show that the number of grafted carboxyphenyl groups on the graphene surface can be controlled by the number of cyclic voltammetry （CV） scans used for electrografting. We further present the fabrication and characterization of an immunosensor based on immobilization of ovalbumin antibody on the graphene surface after the activation of the grafted carboxylic groups via EDC/NHS chemistry. The binding between the surface-immobilized antibodies and ovalbumin was then monitored using Faradaic EIS in [Fe（CN）6]^3-/4- solution. The percentage change of charge transfer resistance （Rct） after binding exhibited a linear dependence for ovalbumin concentrations ranging from 1.0 pg·mL^-1 to 100 ng·mL^-1, with a detection limit of 0.9 pg·mL^-1. Our results indicate good sensitivity of the developed functionalized CVD graphene platform, paving the way for using CVD monolayer graphene in a variety of electrochemical biosensing devices.

MoS2-wrapped silicon nanowires for photoelectro- chemical water reduction

Integration of molybdenum disulfide （MoS2） onto high surface area photocathod is highly desired to minimize the overpotential for the solar-powered hydrogen evolution reaction （HER）. Semiconductor nanowires （NWs） are beneficial use in photoelectrochemistry because of their large electrochemically availab surface area and inherent ability to decouple light absorption and the transpo of minority carriers. Here, silicon （Si） NW arrays were employed as a mod photocathode system for MoS2 wrapping, and their solar-driven HER activil was evaluated. The photocathode is made up of a well-defined MoSJTiO2/Si coaxial NW heterostructure, which yielded photocurrent density up to 15 mA/cm2 （at 0 V vs. the reversible hydrogen electrode （RHE）） with goo stability under the operating conditions employed. This work reveals the earth-abundant electrocatalysts coupled with high surface area NW electrod~ can provide performance comparable to noble metal catalysts for photocathod hydrogen evolution.

Actinide-uranium single-atom catalysis for electrochemical nitrogen fixation

Actinide-based catalysts have been regarded as promising candidates for N_(2) fixation owing to their unique 5f orbital with flexible oxidation states.Herein,we report for the first time the dispersion of uranium(U)single atoms on TiO_(2) nanosheets via oxygen vacancy confinement for N_(2) electroreduction.The single-atom U catalyst exhibited a high NH_(3) yield of 40.57μg h^(-1) mg^(-1),with a reasonably high Faraday efficiency of 25.77%,ranking first among the reported nitrogen-free catalysts.Isotope-labeling operando synchrotron infrared spectroscopy verifies that the key*N_(2)H_(y) intermediate species was derived from the N_(2) gas of the feed.By using operando X-ray absorption spectroscopy,we found enhanced metal-support interaction between U single atoms and TiO_(2) lattice with more U-O_(latt) coordination under working conditions.Theoretical simulations suggest that the evolved 1O_(ads)-U-4O_(latt) moieties act as a critical electronfeedback center,lowering the thermodynamic energy barrier for the N_(2) dissociation and the first hydrogenation step.This work provides the possibility of tailoring the interaction between metal active sites and supports for designing high-performance actinide-based single-atom catalysts.

Pyrene-based covalent triazine framework towards high-performance sensing and photocatalysis applications

Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.