Sb2O3/BiVO4/WO3异质结构建及光电催化合成过氧化氢

采用溶剂热法-旋涂法构建了Sb₂O₃/BiVO₄/WO₃半导体异质结,并采用X射线衍射、扫描电子显微镜、X射线光电子能谱等手段表征了其物化性质。在1.23 V(vs RHE)电位下,BiVO₄/WO₃的光电流密度相对于BiVO₄提高了2倍。进一步复合Sb₂O₃之后,虽然Sb₂O₃/BiVO₄/WO₃薄膜的光电流密度有所下降,但其光电催化产H₂O₂的法拉第效率和产生速率得到明显提升。在1.89V(vs RHE)电位下,3c-Sb₂O₃/BiVO₄/WO₃薄膜产H₂O₂的法拉第效率提高到约19%;1c-Sb₂O     

Se掺杂WO3·0.5H2O/g-C3N4光电催化剂的析氢反应性能

以二氰二胺、硒粉和钨酸钠为前驱体,采用一锅法成功制备出Se掺杂WO₃·0.5H₂O/g-C₃N₄(Se/WCN)催化剂。并采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和X射线光电子能谱(XPS)对样品的物相结构、形貌及化学组成进行表征。与原始的WO₃和g-C₃N₄相比,Se/WCN催化剂的起始电位降到了-0.75 V(vs RHE),电流密度高达70 mA·cm^-2,表现出更高的电催化活性。而光照后,Se/WCN的催化性能进一步提升,起始电位从-0.75 V(vs RHE)降至-0.65 V(vs RHE),电荷转移电阻由371.4Ω减小到310.0Ω。     

硅基光电极光电催化制氢

硅（Si）半导体材料作光电极用于光电催化（PEC）分解水制氢被认为是解决新能源问题比较有希望的措施之一．但目前Si基光电极也面临着光利用率低、不稳定、表面反应动力学缓慢等瓶颈．本文总结了目前Si基光电极材料的发展现状,从表面微纳米结构的设计、保护层的选择、助催化剂的改性三个提高光电极效率的途径,对Si基光电极材料的性能进行了介绍,并对其在该领域的发展前景进行展望．     

In Situ Transformation of Prussian-Blue Analogue-Derived Bimetallic Carbide Nanocubes by Water Oxidation: Applications for Energy Storage and Conversion

Using bimetallic Prussian blue analogue (PBA) as a precursor is effective for preparing electrocatalysts for the oxygen evolution reaction (OER); however, the role of these PBA-derived catalysts in the OER is still ambiguous. Herein, by simply controlling synthesis temperature, a bimetallic PBA-derived O,N-codoped Ni–Fe carbide, can be well tuned to optimize structure and OER performance. Importantly, by a series of ex situ and in situ investigations, real active species of NiFeO_xH_y are in situ formed on the surface during the OER, which reveals a “pre-catalyst” role of O,N-codoped Ni–Fe carbides. Furthermore, it has been successfully applied to highly efficient Zn–air batteries and outplays its RuO₂ counterpart. When applied to photoelectrocatalytic water oxidation as the co-catalyst, it improves the performance of the BiVO₄ photoanode by enhancing hole collecting and transporting ability. We believe this research not only provides a highly efficient and low-cost electrocatalyst for the OER, but also unveils the “pre-catalyst” role of PBA-derived materials in energy-storage and conversion devices.     

Solar Fuels: Photoelectrosynthesis of CO from CO2 at p‐Type Si using Fe Porphyrin Electrocatalysts

Photoelectrocatalytic conversion of CO₂ to CO can be driven at a boron‐doped, hydrogen terminated, p‐type silicon electrode using a meso‐tetraphenylporphyrin Fe^III chloride in the presence of CF₃CH₂OH as a proton source and 0.1 M [NBu₄][BF₄]/MeCN/5 % DMF (v/v) as the electrolyte. Under illumination with polychromatic light, the photoelectrocatalysis operates with a photovoltage of about 650 mV positive of that for the dark reaction. Carbon monoxide is produced with a current efficiency >90 % and with a high selectivity over H₂ formation. Photoelectrochemical current densities of 3 mA cm^?2 at ?1.1 V versus SCE are typical, and 175 turnovers have been attained over a 6 h period. Cyclic voltammetric data are consistent with a turnover frequency of ${k{{{\rm Si}\hfill \atop {\rm obs}\hfill}}}$ =0.24×10⁴ s^?1 for the photoelectrocatalysis at p‐type Si at ?1.2 V versus SCE this compares with ${k{{{\rm C}\hfill \atop {\rm obs}\hfill}}}$ =1.03×10⁴ s^?1 for the electrocatalysis in the dark on vitreous carbon at a potential of ?1.85 V versus SCE.     

Visible light–driven photoelectrocatalytic semiconductor heterojunction anodes for water treatment applications

Research interest in photoelectrocatalysis or photoelectrochemical oxidation processes for water treatment is on the increase. This is because this method has the ability to abate a wide range of recalcitrant organic pollutants from wastewater. The application of visible or solar light, which has the potential to reduce cost, increase safety, and increase sustainability, is a recent direction in this novel electrochemical technology for water treatment. This review focuses on the use of semiconductor heterojunctions as a way of tuning the photoanode towards visible light activation. The classifications, preparations and various applications of semiconductor heterojunction for the removal of organic pollutants from water in the past two years are presented with concluding remarks and future perspective.     

TiO2膜电极光电催化降解苯甲酸的机理研究

利用自制纳米TiO2薄膜作电极, 对苯甲酸光电催化降解过程进行了系统研究. 同时利用扫描电镜(SEM)、X射线衍射图谱(XRD)和光电流-电压响应谱分析光催化剂的微观性质和光电性能. 选取较高的pH 10.5, 以利于苯甲酸降解中间产物的检测(GC/MS). 通过对比光电催化与单一的TiO2光催化体系中苯甲酸的降解动力学、总有机碳(TOC)的去除率、降解产物的生成(GC/MS)及活性自由基物种的产生(ESR), 提出光电催化降解苯甲酸的具体反应路径和氧化机理. 羟基化的苯甲酸在羟基自由基与活性氧自由基的共同作用下, 经由含六个碳原子的二酸(顺式己二烯二酸), 被进一步氧化成小分子酸和CO2.     

焦化含酚废水深度处理过程中间产物对苯二酚的测定

对苯二酚是含酚废水深度氧化降解过程中的中间产物之一[1,2],为了掌握酚氧化降解过程的变化规律及其氧化动力学的规律,建立一种快速、准确的中间产物分析方法是非常重要的。对于酚在深度氧化降解过程中生成微量的、且处于混合体系中的对苯二酚的分析测试,目前除用高效液相色谱外[3,4],尚未见其它测试方法的报道。虽然通过GC,LGC等精密分析仪器能实现混合物中多组分的同时测定,但设备价格昂贵,难以在环境监测中普遍推广。因此,本文针对酚深度氧化降解过程中生成的微量降解中间产物--对苯二酚,提出了应用分光光度分析法,并对其测试条件及影响因素进行了探讨。此法的特点是在混合液中不必事先进行分离即可直接进行测定。这对于含酚废水在氧化降解过程中的监测和控制有重要意义。     

过氧化氢合成方法研究进展*

汇总了近年来H₂O₂的合成方法的主要研究进展,着重介绍了开发的在更温和的反应条件下实现H₂O₂合成的新方法,包括它们的基本原理、优越性和局限性等。推荐将此部分内容在基础无机化学教材中进行更新和补充,这不仅可以丰富元素化学教学内容、拓宽本科生认识范围、增强其环保意识,还可以起到激发学生探索科学、提高创新思维和能力的作用。     

光电催化降解模拟工业染色废水的研究

印染废水毒性大、组分比较复杂、可生化性差,大部分有机物质多具有致癌、致畸、致突变的作用[1-5],常规的处理方法对印染废水的处理效果并不理想[6].