Abstract Tungsten oxide exhibits a favourable band gap for photo-electrochemical applications like water splitting and photo oxidation of water pollutants but suffers from its fast recombination of photo generated electrons and holes due to poor electrical conductivity and its hydrogen evolution level being below the conduction band minimum. In this work, we have incorporated cobalt ferrite nanocrystals as co-catalyst in a hydrothermally synthesized tungsten oxide (WO3) photoanode with an aim to arrest the fast recombination process. Characterization of the nanocomposite containing 5 mol% cobalt ferrite by multiple te chniques confirmed formation of monoclinic WO3nanoplate like structures containing stoichiometric CoFe2O4phase whereas optical absorption spectroscopy gave its optical band gap as 2.1 eV. Electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis and linear sweep voltammetry (LSV) were conducted under illuminated (1.5AM G solar simulated light) and dark conditions that revealed a reduction in the onset potential of pristine tungsten oxide photoanode by ~0.25 V as a result of incorporation of 5 mol% cobalt ferrite nanocrystals owing to an efficient electron transfer before recombination. The photocurrent obtained from the composite photoanode was also found to be 10 times higher than that from bare tungsten oxide photoanode suggesting its potential use as anode material for photoelectrochemical water splitting.

中文翻译：

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铁氧体钴助催化剂对氧化钨纳米片的带隙工程用于太阳能水氧化

摘要 氧化钨在光电化学应用中表现出良好的带隙，如水分解和水污染物的光氧化，但由于导电性差，其析氢水平低于导带最小值，因此其光生电子和空穴的快速复合受到影响。 . 在这项工作中，我们在水热合成的氧化钨 (WO3) 光阳极中加入了钴铁氧体纳米晶体作为助催化剂，目的是阻止快速复合过程。通过多种技术对含有 5 mol% 铁氧体钴的纳米复合材料的表征证实形成了含有化学计量 CoFe2O4 相的单斜晶 WO3 纳米片状结构，而光吸收光谱给出了其光学带隙为 2.1 eV。电化学阻抗谱（EIS），Mott-Schottky 分析和线性扫描伏安法 (LSV) 在光照（1.5AM G 太阳模拟光）和黑暗条件下进行，结果显示原始氧化钨光阳极的起始电位降低了约 0.25 V，这是因为掺入了 5 mol% 钴铁氧体纳米晶体由于重组前的有效电子转移。还发现从复合光阳极获得的光电流是从裸氧化钨光阳极获得的光电流的 10 倍，这表明它有可能用作光电化学水分解的阳极材料。由于复合前的有效电子转移，引入了 5 mol% 的铁氧体钴纳米晶体，因此电压为 25 V。还发现从复合光阳极获得的光电流是从裸氧化钨光阳极获得的光电流的 10 倍，这表明它有可能用作光电化学水分解的阳极材料。由于复合前的有效电子转移，引入了 5 mol% 的铁氧体钴纳米晶体，因此电压为 25 V。还发现从复合光阳极获得的光电流是从裸氧化钨光阳极获得的光电流的 10 倍，这表明它有可能用作光电化学水分解的阳极材料。