College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, PR China.
College of Water Sciences, Beijing Normal University, Beijing, 100875, PR China.
Chemosphere. 2022 Jan;286(Pt 1):131558. doi: 10.1016/j.chemosphere.2021.131558. Epub 2021 Jul 13.
Visible light induced photocatalysis converted solar energy to chemical energy in the form of hydrogen. g-CN modified by thermal oxidation etching, doped S, and nonprecious metal cocatalyst CoS (CoS@SCN) were used for photocatalytic hydrogen production. And then the charge transfer behavior and mechanism of various alcohol sacrificial agents on hydrogen evolution was analyzed by optical characterization, impedance analysis, Mott-Schottky, and photocurrent tests. The relationship between the structure and catalytic performance was also explored using characterization methods. The results showed that CoS significantly improved the light absorption of g-CN, and carrier migration and separation. And when the sacrificial agent was triethanolamine, the nanocomposite CoS@SCN exhibited best catalytic performance with the highest hydrogen activity of 223.6 μmol g h, the minimum volume in-phase charge transfer resistance with 55.19 Ω and the maximum photocurrent and photocurrent density with 5.5 μA cm and 0.63 mA cm. The more negatively charged surface of organic alcohols were, the easier they were to react with holes, thus enhanced charge transfer and hydrogen production efficiency. This report provides guidance for the selection of hydrogen producing sacrificial agents and preparation of highly charge-efficient catalysts. And it also provides a theoretical basis for hydrogen production from wastewater and environmental remediation.
可见光诱导光催化将太阳能转化为氢气的化学能。通过热氧化刻蚀、掺杂 S 和非贵金属助催化剂 CoS（CoS@SCN）对 g-CN 进行改性，用于光催化制氢。然后通过光学特性、阻抗分析、Mott-Schottky 和光电流测试分析了各种醇牺牲剂在析氢反应中的电荷转移行为和机理。还采用了表征方法探讨了结构与催化性能之间的关系。结果表明，CoS 显著提高了 g-CN 的光吸收、载流子迁移和分离能力。当牺牲剂为三乙醇胺时，纳米复合材料 CoS@SCN 表现出最佳的催化性能，具有最高的氢气活性 223.6 μmol·g·h、最小的同相电荷转移电阻 55.19 Ω 和最大的光电流和光电流密度 5.5 μA·cm 和 0.63 mA·cm。有机醇的表面带负电荷越多，与空穴反应越容易，从而增强了电荷转移和产氢效率。本报告为选择产氢牺牲剂和制备高电荷效率催化剂提供了指导，也为废水和环境修复中的制氢提供了理论依据。
