title: 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.
abstract: 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.
authors: College of Chemistry, Jilin University, Changchun 130012, People's Republic of China. xietf@jlu.edu.cn.
authors: Dandan
authors: D
authors: Xu
authors: Zewen
authors: Z
authors: Fu
authors: Dejun
authors: D
authors: Wang
authors: Yanhong
authors: Y
authors: Lin
authors: Yanjun
authors: Y
authors: Sun
authors: Dedong
authors: D
authors: Meng
authors: Teng
authors: T
authors: Feng Xie