Photoassisted Hydrothermal Synthesis of IrOx-TiO2 for Enhanced Water Oxidation
Photoassisted Hydrothermal Synthesis of IrOx-TiO2 for Enhanced Water Oxidation
复制标题
光辅助水热合成 IrOx-TiO2 用于增强水氧化
DOI：
10.1021/acssuschemeng.9b04590
复制
发表时间：
2019-11-04
影响因子：
8.4
通讯作者：
Liu, Shengzhong
中科院分区：
文献类型：
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作者：
Li, Ping;Kong, Lingqiao;Liu, Shengzhong
水氧化被认为是水分解的瓶颈，特别是通过光催化过程，因此仍然需要大大改进的催化剂体系，其不仅具有合适的载体分离性能，而且具有穿过催化剂-溶液界面的低载体迁移阻力。在此，报道了光辅助水热法来合成亲水性半导体纳米颗粒的样品，即，TiO 2和IrOx-TiO 2，与参比样品相比显示出优异的亲水性。X射线光电子能谱（XPS）中的O是线证明了TiO 2表面存在大量的表面羟基和吸附水。负载的Ir物种主要以金属态存在，含有少量IrO 2。通过表面OH基团和负载IrOx的协同作用，IrOx-TiO 2 -150-L样品在LED-365光照下表现出最佳的光催化水氧化性能，达到56.67 μ mol/g. h。此外，样品对可见光（LED-425）表现出光电流响应。电化学阻抗谱和时间分辨光致发光谱结果表明，IrOx-TiO 2-L样品具有较低的载流子固液界面迁移阻力和较弱的体载流子复合比，具有良好的光催化水氧化活性。
Water oxidation is regarded as a bottleneck in water splitting, especially via the photocatalytic process, and thus there is still a need for a greatly improved catalyst system that not only has suitable carrier separation performance but also has low carrier migration resistance across the catalyst-solution interface. Herein, a photoassisted hydrothermal method is reported to synthesize samples of hydrophilic semiconductor nanoparticles, i.e., TiO2 and IrOx-TiO2, which show excellent hydrophilic behavior in comparison to reference samples. The O is line in X-ray photoelectron spectroscopy measurement proves that many surface OH groups and adsorbed water exist on the surface of the TiO2. The loaded Ir species mainly exists in the metal state with a small amount of IrO2. Through the synergistic effect of surface OH groups and the loaded IrOx, the IrOx-TiO2-150-L sample gives the best photocatalytic water oxidation performance of 56.67 mu mol/g.h under LED-365 illumination. Moreover, the sample exhibits a photocurrent response to visible light (LED-425). The electrochemical impedance spectroscopy and time-resolved photoluminescence results confirm that the samples of IrOx-TiO2-L possess low carrier solid-liquid interface migration resistances and weak bulk carrier recombination ratios, and thus excellent photocatalytic water oxidation activity is obtained.