Cos as Co-Catalyst for Enhancing the Tio2 Photoelectrochemical Water Splitting

Abstract

Titanium dioxide is a semiconductor that widely applied because it is environmentally friendly and has good catalytic activity. However, the wide band gap of TiO2 limits its application in photocatalytic activities. Cobalt sulfide (CoS) is extensively used as a photocatode in photoelectochemistry because it has good electrochemical activity, low cost and non-toxic. The formation of p-n junction between TiO2 and CoS can reduce the band gap of the former, and the load transfer of photoelectrochemical activity can be increased. TiO2/CoS is a promising photocatalyst in enhancing photoelectrochemical performance. In this work, a TiO2/CoS thin film was synthesized through hydrothermal method to study the effect of CoS on TiO2 and improve the photoelectrochemical performance. Characterization were performed using X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and UV reflectance. Results showed that as-synthesized TiO2/CoS was a mixed phase of TiO2 (anatase, rutile) and CoS with agglomerate-shaped small particles. The band gap of TiO2 was reduced after CoS was loaded at 2.75 eV. The density of as-synthesized sample was 1.2572 mA at 1 V compared with Ag/AgCl under light irradiation.