Sustainable and efficient hydrogen evolution over a noble metal-free WP double modified ZnxCd1-xS photocatalyst driven by visible-light
Sustainable and efficient hydrogen evolution over a noble metal-free WP double modified ZnxCd1-xS photocatalyst driven by visible-light
复制标题
可见光驱动下无贵金属WP双改性ZnxCd1-xS光催化剂可持续高效析氢
DOI：
10.1039/c9dt01421g
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发表时间：
2019-08-07
影响因子：
4
通讯作者：
Yuan, Hong
中科院分区：
文献类型：
--
作者：
Yan, Xian;Jin, Zhillang;Yuan, Hong
在能源获取方面，光催化裂解水制氢的研究已经成为我们从理论研究向实际应用过渡的枢纽。半导体的电荷分离和表面氧化还原反应是影响其产氢活性的关键因素。在这项研究中，我们使用了一种n型半导体WP作为助催化剂来修改的ZnxCd 1-xS的固溶体，并发现它在可见光照射下具有良好的光催化活性。紫外漫反射光谱表明复合催化剂的吸收带发生了红移，对可见光有较强的吸收。在匹配能带结构的作用下，复合催化剂的荧光寿命缩短（2.33 ns），电子注入速率加快（K-et = 0.58 × 10（9）s（-1））。在此条件下，复合催化剂的产氢活性提高最终表现为产氢速率的提高，最高可达15028.6 μ mol g（-1）h（-1）。此外，通过在四个测试循环之后的第五个循环中添加新鲜乳酸催化剂而产生的氢气的产率大大提高。显然，WP的加入使复合催化剂成为一种高效、稳定的光催化剂，是一种非贵金属助催化剂。最后，通过一系列表征实验（SEM、TEM、XPS、BET、Mott-Schottky等），提出了WP/ZnxCd_（1-x）S高效产氢的可能机理。这为设计有效的助催化剂改性半导体以提高光催化活性提供了新的认识。
In terms of energy acquisition, research on the photocatalytic cracking of water to produce hydrogen has become a hub for us to make a transition from theoretical research to practical applications. Charge separations and surface redox reactions of semiconductors are key factors that affect hydrogen production activity. In this study, we used an n-type semiconductor WP as a cocatalyst to modify the solid solution of ZnxCd1-xS and found it to have excellent photocatalytic activity under visible light irradiation. Ultraviolet diffuse reflectance spectroscopy showed the red shift of the absorption band of the composite catalyst and the strong absorption of visible light. Under the action of the matching energy band structure, the fluorescence lifetime of the composite catalyst is shortened (2.33 ns) and the electron injection rate is accelerated (K-et = 0.58 x 10(9) s(-1)). Under these favorable conditions, the increased hydrogen production activity of the composite catalyst is finally reflected in the enhanced hydrogen production rate, which reached up to 15 028.6 mu mol g(-1) h(-1). In addition, the yield of hydrogen produced by adding a fresh lactic acid catalyst in the fifth cycle after four cycles of testing was greatly improved. Obviously, the addition of WP turns the composite catalyst into a photocatalyst with high efficiency, stability and is a non-noble metal cocatalyst. Finally, through a series of characterization experiments (SEM, TEM, XPS, BET, Mott-Schottky et al.), we proposed the possible mechanism of WP/ZnxCd1-xS that efficiently promotes hydrogen production. This provides new understanding for designing an effective cocatalyst modified semiconductor to improve photocatalytic activity.