Ag-Pd alloy decorated ZnIn 2 S 4 microspheres with optimal Schottky barrier height for boosting visible-light-driven hydrogen evolution
Ag-Pd alloy decorated ZnIn 2 S 4 microspheres with optimal Schottky barrier height for boosting visible-light-driven hydrogen evolution
复制标题
Ag-Pd 合金装饰的 ZnIn2 S4 微球具有最佳肖特基势垒高度，可促进可见光驱动的析氢
DOI：
10.1016/j.jmst.2021.12.003
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发表时间：
2022-01-19
影响因子：
10.9
通讯作者：
Zou, Zhigang
中科院分区：
文献类型：
--
作者：
Liu, Chao;Zhang, Yulong;Zou, Zhigang
锌铟硫化物（ZnIn 2S 4）在光催化应用中存在载流子复合速率快和捕光能力不足两个主要缺点。本文采用化学还原法将联合收割机包裹的Ag-Pd合金纳米颗粒（NPs）与球形ZnIn 2S 4（ZIS）复合。通过优化Ag：Pd摩尔比和总负载量，最佳的Ag 0.2 5 Pd 0.75 ZIS样品在可见光下具有最大的放氢速率（12 5.4 μ mol/h），高于ZIS、Ag-ZIS和Pd-ZIS。与Pd负载（肖特基效应）相比，Ag NPs负载通过其等离子体效应对PHE反应的贡献可以忽略不计。Ag0.25Pd0.75-ZIS样品在400 nm和420 nm处的表观量子产率（AQY）分别达到18.3%和15.8%。Ag0.25Pd0.75-ZIS样品光催化析氢活性的提高主要是由于光催化协同效应。首先，通过负载Ag-Pd合金的等离子体杂化可以显著提高ZIS的光捕获能力。其次，Ag-Pd合金与ZIS界面之间形成的最佳肖特基势垒高度有利于延长电子-空穴对寿命，促进载流子分离，从而提高PHE效率。密度泛函理论（DFT）分析表明，H * 在Pd 0.75 Ag 0.2 5合金上的吸附能非常接近于零，理论上具有最高的析氢活性，这与实验结果相一致。结合理论计算和实验结果，提出并验证了合理的光催化机理。(c)2022由Elsevier Ltd代表Journal of Materials Science & Technology编辑部出版。
Rapid charge carrier recombination rate and insufficient light harvesting capacity are two dominating drawbacks encountered in zinc indium sulfide (ZnIn 2 S 4 ) for photocatalytic applications. Herein, a chemical reduction method was performed to combine bimetallic Ag-Pd alloy nanoparticles (NPs) with spherical-like ZnIn 2 S 4 (ZIS). By optimizing Ag:Pd molar ratio and overall loading amount, the optimal Ag 0.25 Pd 0.75 -ZIS sample exhibited a maximum H 2 evolution rate (125.4 mu mol/h) under visible light, which was higher than that of ZIS, Ag-ZIS and Pd-ZIS. The loading of Ag NPs contribution to PHE reaction by its plasmonic effect was negligible compared to that of Pd loading (Schottky effect). The apparent quantum yield (AQY) values over Ag 0.25 Pd 0.75 -ZIS sample could reach up to 18.3% at 400 nm and 15.8% at 420 nm. The enhanced activity for photocatalytic hydrogen evolution (PHE) over Ag 0.25 Pd 0.75 -ZIS sample was mainly due to the bimetallic synergistic effect that presented as follows. Firstly, the plasmon hybridization by loading Ag-Pd bimetallic alloy can significantly increase light harvesting capacity of ZIS. Secondly, the optimal Schottky barrier height formed between Ag-Pd alloy and ZIS interface was beneficial for prolonging electron-hole pair lifetimes, promoting charge carrier separation and thus facilitating PHE efficiency. Density functional theory (DFT) analysis indicated that the adsorption energy of H * over Pd 0.75 Ag 0.25 alloy was very close to zero and thus theoretically possessed the highest activity for H 2 evolution, which is in line with experimental results. Combined theoretical calculation with experimental results, a reasonable photocatalytic mechanism was proposed and verified. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.