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

摘要

Titanium dioxide is a semiconductor that widely applied because it is environmentally friendly and has good catalytic activity. However, the wide band gap of TiO_2 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 TiO_2 and CoS can reduce the band gap of the former, and the load transfer of photoelectrochemical activity can be increased. TiO_2/CoS is a promising photocatalyst in enhancing photoelectrochemical performance. In this work, a TiO_2/CoS thin film was synthesized through hydrothermal method to study the effect of CoS on TiO_2 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 TiO_2/CoS was a mixed phase of TiO_2 (anatase, rutile) and CoS with agglomerate-shaped small particles. The band gap of TiO_2 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.