Preparation and characterization of Nano-graphite/TiO2 composite photoelectrode for photoelectrocatalytic degradation of hazardous pollutant.

Abstract Nano-graphite(Nano-G)/TiO 2 composite photoelectrode was fabricated via sol-gel reaction, followed by the hot-press approach. The morphology, structure and light absorption capability of composite was characterized by various characterizations. The photoelectrochemical property and photoelectrocatalytic(PEC) activity of photoelectrode were also investigated. Results revealed that anatase TiO 2 nanoparticles with an average diameter of 10 nm were dispersed uniformly on the thickness of 2–3 nm Nano-G, and Ti O C bond was formed. The absorption edge of Nano-G/TiO 2 photoelectrode was red-shifted towards low energy region and the enhanced visible light absorption was obtained. The charge transfer resistance of Nano-G/TiO 2 photoelectrode was significantly decreased after the addition of Nano-G. And its transient photoinduced current was 10.5 times the value achieved using TiO 2 electrode. Nano-G/TiO 2 photoelectrode displayed greatly enhanced PEC activity of 99.2% towards the degradation of phenol, which was much higher than the 29.1% and 58.3% degradation seen on TiO 2 and Nano-G electrode, respectively. The highly efficient and stable PEC activity of Nano-G/TiO 2 photoelectrode was attributed to the synergy effect between photocatalysis and electrocatalysis, as well as enhanced light absorption ability and higher separation efficiency of photogenerated charge carriers. Moreover, contribution of series of reactive species to the PEC degradation of Nano-G/TiO 2 photoelectrode was determined.