A Ni(OH)2-modified Ti-doped α-Fe2O3 photoanode for improved photoelectrochemical oxidation of urea: the role of Ni(OH)2 as a cocatalyst.
A Ni(OH)2-modified Ti-doped α-Fe2O3 photoanode for improved photoelectrochemical oxidation of urea: the role of Ni(OH)2 as a cocatalyst.
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DOI：
10.1039/c5cp03310a
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
Dandan Xu;Zewen Fu;Dejun Wang;Yanhong Lin;Yanjun Sun;D. Meng;Teng feng Xie
中科院分区：
文献类型：
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作者：
Dandan Xu;Zewen Fu;Dejun Wang;Yanhong Lin;Yanjun Sun;D. Meng;Teng feng Xie
对于基于光催化剂的PEC系统，在半导体（例如太阳能活性材料）上负载适当的助催化剂可以由于抑制光生电荷复合而显著改善PEC活性。但是关于助催化剂在光生载流子的空间分离中的作用的直接信息很少。本工作采用表面光电压谱（SPS）、瞬态光电压（TPV）、光电化学阻抗谱（PEIS）和瞬态光电流测量相结合的方法，研究了Ni（OH）2作为助催化剂对Ni（OH）2改性的Ti掺杂α-Fe 2 O3光电转换性能的真实的作用。结果表明，Ni（OH）2作为空穴存储层，增强了光生载流子的分离，增加了空穴的寿命，这有助于增强光电流。此外，Ni（OH）2是尿素氧化的良好助催化剂，其抑制过电位，导致起始电位负移。
For semiconductor-based PEC systems, loading an appropriate cocatalyst on a semiconductor (such as a solar-active material) can significantly improve the PEC activity due to the suppression of photogenerated charge recombination. But there is little direct information about the role of a cocatalyst in the spatial separation of photogenerated charge carriers. In our work, a combination of surface photovoltage spectroscopy (SPS), transient photovoltage (TPV) technique, photoelectrochemical impedance spectroscopy (PEIS) and transient photocurrent measurements was used to study the real role of Ni(OH)2 as a cocatalyst for the enhanced PEC performance of Ni(OH)2-modified Ti-doped α-Fe2O3. It was found that Ni(OH)2 as a hole storage layer enhances the separation of photogenerated charge carriers and increases the lifetime of holes, which contributed to the enhanced photocurrent. In addition, Ni(OH)2 is a good cocatalyst for urea oxidation which suppresses the over-potential, resulting in a negative shift of the onset potential.