Ti3+ self-doped TiO2 photoelectrodes for photoelectrochemical water splitting and photoelectrocatalytic pollutant degradation

Abstract

To improve the harvesting of visible light and reduce the recombination of photogenerated electrons and holes, Ti3+ self-doped TiO2 nanoparticles were synthesized and assembled into photoanodes with high visible light photoelectrochemical properties. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectra, electron resonance spectroscopy and energy dispersive X-ray spectra were used to characterize the structure, crystallinity, morphology and other properties of the obtained nanoparticles. UV–visible diffuse reflectance spectra showed that the Ti3+ self-doped TiO2 nanoparticles had a strong absorption between 400 and 800nm. Moreover, when hydrothermal treatment time was prolonged to 22h, the heterogeneous junction was formed between the anatase and rutile TiO2, where the anatase particles exposed highly active {001} facets. Under visible light irradiation, the Ti3+ self-doped TiO2 electrode exhibited an excellent photoelectrocatalytic degradation of rhodamine B (RhB) and water splitting performance. Intriguingly, by selecting an appropriate hydrothermal time, the high photoconversion efficiency of 1.16% was achieved.