Comparative Study of p-type CuBi2O4 Films and CuBi2O4 Nanopillars Photocathode for High Performance Photoelectrochemical Water Splitting

Abstract

Traditional thin films and nanostructure are the most reasonable candidates to build the next generation of photoelectrochemical water splitting system with outstanding optical and electrical properties. Especially the use of nanostructure arrays as photoelectrodes might complement the traditional semiconductor photoelectrodes in providing close transfer distance of photoinduced carriers and the increase in the surface reaction sites than thin films. Both of the reasons reduce the probability of carriers recombination and thus enhancing the photoelectrochemical performances. In this work, we demonstrated highly efficient water splitting performance of CuBi2O4 nanopillars compared to thin film CuBi2O4 photocathode. The CuBi2O4 nanopillars were fabricated by electrodeposition on anodized aluminum oxide (AAO) template. The CuBi2O4 nanopillars photocathode gave a notable improvement in photocurrent, from -0.50 to -1.50 mA cm-2 at -0.45 V vs. Ag/AgCl by the external quantum yield more than 3 times at wavelength 420 nm. Finally, the result of the study appealed that the photoelectrode based on CuBi2O4 nanostructure arrays is an encouraging system for showing efficient water splitting system under visible light.