水热法制备Pr掺杂Bi2WO6三维花状微球的光催化性能

通过水热法制备稀土Pr掺杂Bi₂WO₆三维花状微球,利用XRD、SEM、N₂吸附-脱附、紫外-可见吸收光谱和光致发光光谱对所制备的光催化材料进行表征。通过降解亚甲基蓝评价样品的光催化活性。结果表明,1.0% Pr-Bi₂WO₆样品的可见光催化活性最佳,降解率达到95%。Pr掺杂提高了催化剂的可见光吸收性能并且能够束缚光生电子使得电子空穴对有效分离从而获得强氧化物质。对其光催化降解做出了合理的解释。     

SiO2@AgCl:Ag纳米复合材料:一种可见光催化降解罗丹明B的高效等离子体光催化剂

采用多元醇沉淀以及光化学还原法制备了SiO₂担载AgCl:Ag等离子体纳米粒子。通过表征发现SiO₂@AgCl:Ag粒子呈立方-四足角状。同时,由于表面Ag簇的等离子共振效应,该催化剂在可见光区有很强的光吸收,可用于在高效降解稳定的有机染料,例如,罗丹明B。合成的SiO₂@AgCl:Ag复合催化剂可在2 min内将罗丹明B分子完全降解。自由基捕获实验进一步探究发现O₂·^-和·OH是参与降解反应的主要氧化活性物种。以上SiO₂@AgCl:Ag的这些特性使其在水净化和环境治理方面有着潜在的应用。     

磁载光催化剂Fe3O4/C/TiO2的制备及对三氯苯酚的降解

以FeCl3为铁源,葡萄糖为碳源,钛酸四丁酯为钛源,采用水热法制备了磁载光催化剂Fe3O4/C/TiO2,用TEM、EDX、VSM、XRD和IR对Fe3O4/C/TiO2的粒径、形貌和物相等进行了表征。研究了该催化剂对三氯苯酚的降解性能,探讨了其重复使用的可能性,用荧光光谱法推测了可能的反应机理。结果表明该材料结合了光催化与可再生的优点,1 g·L-1 Fe3O4/C/TiO2在18 W紫外灯下,50 min内可将三氯苯酚降解97.9%以上,6次循环使用后降解率仍保持在95.1%,降解过程中有羟基自由基生成。     

Photocatalytic Activity of High Aspect Ratio TiO2 Nanorods

In this article, TiO₂ nanorods (aspect ratio >20) were prepared through a polyol process and doped with metal ions (Cu²⁺, Ni²⁺, Fe³⁺, and Cr³⁺). Compared with TiO₂ nanoparticles, the TiO₂ nanorods displayed relatively higher photocatalytic activity for the degradation of copper sulfophthalocyanine. Moreover, the photocatalytic activity was greatly enhanced when the metal ions were doped in the TiO₂ nanorods.     

硫掺杂橄榄状BiVO4上可见光降解亚甲基蓝和甲醛水溶液性能

在无和有S源(Na₂S或硫脲)存在的条件下,采用十二胺辅助的醇-水热法制备了多孔单斜晶相结构的BiVO_4-δ和不同含量S掺杂的BiVO_4-δ光催化剂.利用多种手段表征了催化材料的物化性质,评价了它们在可见光照射下催化降解亚甲基蓝或甲醛的反应活性.结果表明,所制光催化剂为单斜白钨矿晶相结构,具有多孔橄榄状形貌,比表面积为8.4-12.5m²/g,带隙能为2.40-2.48eV.在S掺杂BiVO_4-δ表面同时含有Bi⁵⁺,Bi⁴⁺,V⁵⁺和V⁴⁺物种.S掺杂对BiVO_4-δ光催化剂的活性影响很大.在可见光下照射下,BiVO_4-δS_0.08光催化剂对亚甲基蓝和甲醛降解反应显示出最高的光催化活性,这与其较高的表面氧物种浓度和较低的带隙能相关.     

Decatungstate Incorporated Metal-organic Framework for Degradation of Rhodamine B under Sunlight Irradiation

A new decatungstate incorporated metal-organic framework {[Co2（bpdo）5（H2O）n- W10O32]}n·nbpdo·2nH2O（1, bpdo = 4,4＇-bis（pyridine-N-oxide） has been synthesized through a one-step hydrothermal reaction and characterized by elemental analyses, IR, solid UV-vis absorption spectra, and single-crystal X-ray diffraction. The structural analysis indicates that 1 displays a one-dimensional ladder structure with [W10O32]4- as guest incorporated by electrostatic interaction. The photocatalytic property of the framework toward a rhodamine B （RhB） solution was also investigated. The results indicated that compound 1 possesses high photocatalytic activity in heterogeneous system under sunlight irradiated.     

氧化亚铜微/纳米结构的形貌可控制备及光催化和防污性能

利用简便易行的液相法,采用葡萄糖为还原剂,通过调整加料方式、反应温度、NaOH用量等条件,实现具有{110}截面八面体、八面体和短足形等形貌的Cu₂O微/纳米结构的可控制备,运用透射电子显微镜、扫描电子显微镜、紫外可见分光光度计等对产物进行组成、结构、形貌和光响应的表征,对Cu₂O的形貌结构和生长机理进行研究。对比和优化了具有不同形貌的Cu₂O微/纳米结构对甲基橙染料的光催化性能。将不同形貌的微/纳米Cu₂O作为防污剂复配的自抛光防污涂料,涂层磨蚀率、接触角与实海挂板实验证明该涂料具有良好的防污性能。     

When C–H bond functionalization meets visible-light photoredox catalysis

In recent years, visible-light-mediated C–H bond functionalization has become an emerging field at the forefront of organic synthesis. It is of considerable interest to academic and industrial chemists owing to the atom/step economical features as well as the overall sustainability. In this Letter, we mainly discussed the recent typical examples in sp² and sp³ C–H bond functionalization by means of visible-light photoredox catalysis.     

太阳能光催化分解水制氢※

利用太阳能光催化分解水制氢是解决能源环境问题并实现太阳能有效转化和储存最有前途的技术之一, 这一“圣杯”式反应经过几十年不懈努力取得了诸多重要研究进展. 本文将综述光催化分解水制氢体系的基本概念、活性测试方法与注意事项、光催化材料种类等; 并从光催化分解水制氢的光吸收、光生电荷分离和表面催化反应等基本过程和关键科学问题的角度总结其重要研究进展, 最后对于太阳能光催化分解水制氢的挑战和潜在的发展方向进行分析和展望. 希望通过本综述的简要介绍能让刚从事光催化分解水制氢研究的青年科技人员清晰地了解掌握该领域的一些基本概念、操作规范、研究总体进展和现状等.     

Utilization of photocatalysts in decarboxylative coupling of carboxylic N-hydroxyphthalimide (NHPI) esters

Recently, the visible-light photoredox decarboxylative couplings of N-(acyloxy)phthalimides (NHPI esters) and its derivatives have become an efficient chemical transformation. Under visible light, the NHPI esters undergo a single-electron transfer (SET) process to afford the corresponding carbon or nitrogen radicals that participate in many chemical transformations. The photoredox decarboxylative couplings have been applied to achieve construction of an array of carbon–carbon and carbon–heteroatom bonds as well as the synthesis of carbocycles and heterocycles. This review categorises photocatalysts, discusses the application and catalysis mechanisms of NHPI esters, and details recent progress in this field.