In-situ carbon-coated TiO2 boosting the visible-light photocatalytic hydrogen evolution

Abstract

A straightforward hydrolysis–carbonization strategy for synthesizing carbon-coated TiO2 photocatalyst is developed. During the calcination process, boric acid functions as a template to maintain the size of TiO2 nanoparticles, expose more active surfaces, and further improve photocatalytic activity. And butyl alcohol generated from the hydrolysis of butyl titanate is carbonized and covered on the surface of TiO2 nanoparticles, forming in-situ carbon-coated TiO2 photocatalyst. Under the irradiation of Xenon lamp, the catalyst TiO2-500-W shows excellent photocatalytic hydrogen evolution ability (434.91 μmol h−1 g−1) and recycling stability. The band gap of carbon-coated TiO2-500-W is 2.82 eV so that it can even promote the hydrogen evolution under visible-light irradiation. Experiments and DFT calculations reveal that the presence of carbon sheet on TiO2 can reduce the band gap, generate valence band tail, and decrease the work-function, which facilitate the improvement of photocatalytic activity for H2 evolution.