Co3O4 Nanoparticles as Robust Water Oxidation Catalysts Towards Remarkably Enhanced Photostability of a Ta3N5 Photoanode
Co3O4 Nanoparticles as Robust Water Oxidation Catalysts Towards Remarkably Enhanced Photostability of a Ta3N5 Photoanode
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Co3O4 纳米颗粒作为强大的水氧化催化剂可显着增强 Ta3N5 光阳极的光稳定性
DOI：
10.1002/adfm.201102966
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发表时间：
2012-07-24
影响因子：
19
通讯作者：
Zou, Zhigang
中科院分区：
文献类型：
--
作者：
Liao, Maijia;Feng, Jianyong;Zou, Zhigang
尽管Ta3N5吸收了大部分可见光谱，但随着时间的推移，在水光电解中遇到的光电流迅速下降仍然是Ta3N5光电极实际应用的严重障碍。本研究通过采用Co3O4纳米颗粒水氧化催化剂（WOC）和碱性电解质，显著提高了Ta3N5电极的光稳定性。与Co(OH)x/Ta3N5和IrO2/Ta3N5光阳极相比，Co3O4/Ta3N5光阳极表现出迄今为止最好的抗光腐蚀耐久性。具体来说，在1.2 V与RHE（可逆氢电极）照射2 h后，大约75%的初始稳定光电流仍然存在。同时，在1个太阳和1.5 G模拟阳光下，在1.2 V vs. RHE下，Co3O4/Ta3N5光阳极上获得了3.1 mA cm−2的光电流密度。在电镜观察和光电化学测量的基础上讨论了相对高稳定性的原因，并通过X射线光电子能谱分析监测了表面氮含量。
Despite the fact that Ta3N5 absorbs a major fraction of the visible spectrum, the rapid decrease of photocurrent encountered in water photoelectrolysis over time remains a serious hurdle for the practical application of Ta3N5 photoelectrodes. Here, by employing a Co3O4 nanoparticle water oxidation catalyst (WOC) as well as an alkaline electrolyte, the photostability of Ta3N5 electrode is significantly improved. Co3O4/Ta3N5 photoanode exhibits the best durability against photocorrosion to date, when compared with Co(OH)x/Ta3N5 and IrO2/Ta3N5 photoanodes. Specifically, about 75% of the initial stable photocurrent remains after 2 h irradiation at 1.2 V vs. RHE (reversible hydrogen electrode). Meanwhile, a photocurrent density of 3.1 mA cm−2 has been achieved on Co3O4/Ta3N5 photoanode at 1.2 V vs. RHE with backside illumination under 1 sun AM 1.5 G simulated sunlight. The reason for the relatively high stability is discussed on the basis of electron microscopic observations and photoelectrochemical measurements, and the surface nitrogen content is monitored by X‐ray photoelectron spectroscopic analysis.