Effect of Dual-Cocatalyst Surface Modification on Photodegradation Activity, Pathway, and Mechanisms with Highly Efficient Ag/BaTiO3/MnOx
Effect of Dual-Cocatalyst Surface Modification on Photodegradation Activity, Pathway, and Mechanisms with Highly Efficient Ag/BaTiO3/MnOx
复制标题
双助催化剂表面修饰对高效Ag/BaTiO 3 /MnO x 光降解活性、途径和机制的影响
DOI：
10.1021/acs.langmuir.9b02714
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发表时间：
2020-01-21
期刊：
影响因子：
3.9
通讯作者：
Pu, Yongping
中科院分区：
文献类型：
--
作者：
Cui, Yongfei;Sun, Huanhuan;Pu, Yongping
助催化剂表面负载被认为是提高太阳能转化效率的有效策略。然而，表面改性与助催化剂的光降解途径和潜在的机制的影响仍然不清楚。在这里，我们已经使用铁电BaTiO 3作为衬底，和还原助催化剂Ag和氧化助催化剂MnOx已成功地装载到BaTiO 3同时通过一步光沉积方法证明了X射线光电子能谱（XPS），扫描电子显微镜（SEM），和高分辨率透射电子显微镜（HRTEM）。首次系统研究了双助催化剂表面负载量对罗丹明B光降解的影响。首先，双助催化剂改性的BaTiO 3的光催化性能优于单助催化剂负载的BaTiO 3，Ag/BaTiO 3/MnOx的光降解速率分别是Ag/BaTiO 3和BaTiO 3/MnOx的3倍和12倍。信贷之间的协同效应的还原和氧化的助催化剂，促进电荷载流子的分离和迁移的瞬态光电流，电化学阻抗，和光致发光（PL）光谱调查验证。其次，除了增强的光降解活性，光降解途径被发现被改变，以及当使用Ag/BaTiO 3/MnOx。高效液相色谱（HPLC）分析表明，在Ag/BaTiO 3/MnOx体系中，一个高选择性的分步脱乙基过程占主导地位，而在Ag/BaTiO 3体系中则相反.这是由于染料分子的吸附模式不同造成的。自由基捕获实验表明空穴在降解过程中起主要作用，循环实验证明Ag/BaTiO 3/MnOx具有良好的稳定性。我们的研究结果可能会增加另一层理解深度助催化剂表面改性在光降解应用。
Cocatalyst surface-loading has been regarded as an effective strategy to promote solar-energy-conversion efficiency. However, the potential influence of surface modification with cocatalysts on the photodegradation pathway and the underlying mechanisms is still unclear. Herein, we have used ferroelectric BaTiO3 as the substrate, and both the reduction cocatalyst Ag and the oxidation cocatalyst MnOx have been successfully loaded onto BaTiO3 simultaneously by a one-step photodeposition method as evidenced by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The influence of dual-cocatalyst surface-loading on photodegradation of rhodamine B has been systematically investigated for the first time. First, the dual-cocatalyst-modified BaTiO3 outperformed over the single-cocatalyst-loaded BaTiO3, and the photodegradation rate of Ag/BaTiO3/MnOx is about 3 times and 12 times as high as that of Ag/BaTiO3 and BaTiO3/MnOx, respectively. The credit is given to the synergistic effect between the reduction and oxidation cocatalysts, prompting charge carrier separation and migration as verified by the transient photocurrent, electrochemical impedance, and photoluminescence (PL) spectrum investigation. Second, in addition to the boosted photodegradation activity, the photodegradation pathway is found to be altered as well when using Ag/BaTiO3/MnOx. High-performance liquid chromatography (HPLC) analysis indicated that a highly selective stepwise deethylation process predominates over chromophore cleavage in the Ag/BaTiO3/MnOx system, while it is reverse for the Ag/BaTiO3 system. This phenomenon is attributed to the different dye molecule adsorption modes. Furthermore, the radical trapping experiment shows that holes play a major role in the degradation process, and the recycle test proves the excellent stability of Ag/BaTiO3/MnOx. Our findings may add another layer of understanding depth to cocatalyst surface modification in photodegradation applications.