Synergistic effects of carbon doping and coating of TiO2 with exceptional photocurrent enhancement for high performance H2 production from water splitting

Abstract

The “one pot” simultaneous carbon coating and doping of TiO2 materials by the hydrolysis of TiCl4 in fructose is reported. The synergistic effect of carbon doping and coating of TiO2 to significantly boost textural, optical and electronic properties and photocurrent of TiO2 for high performance visible light H2 production from water splitting has been comprehensively investigated. Carbon doping can significantly increase the thermal stability, thus inhibiting the phase transformation of the Titania material from anatase to rutile while carbon coating can suppress the grain aggregation of TiO2. The synergy of carbon doping and coating can not only ensure an enhanced narrowing effect of the electronic band gap of TiO2 thus extending the absorption of photocatalysts to the visible regions, but also promote dramatically the separation of electron-hole pairs. Owing to these synergistic effects, the carbon coated and doped TiO2 shows much superior photocatalytic activity for both degradation of organics and photocatalytic/photoelectrochemical (PEC) water splitting under simulated sunlight illumination. The photocatalytic activity of obtained materials can reach 5, 4 and 2 times higher than that of pristine TiO2, carbon doped TiO2 and carbon coated TiO2, respectively in the degradation of organic pollutants. The carbon coated and doped TiO2 materials exhibited more than 37 times and hundreds of times photocurrent enhancement under simulated sunlight and visible light, respectively compared to that of pristine TiO2. The present work providing new comprehensive understanding on carbon coating and doping effect could be very helpful for the development of advanced TiO2 materials for a large series of applications.