TiO2–graphene composites with exposed {001} facets produced by a one-pot solvothermal approach for high performance photocatalyst

Abstract

TiO₂–graphene (TOG) composites with exposed TiO₂ {001} facets were prepared by a solvothermal approach without any addition of surfactants or capping agents, only using titanium isopropoxide and graphene oxide ethanol suspension as the precursors. Graphene was covered uniformly and densely with anatase TiO₂ nanoparticles, exposing the {001} facets. The X-ray photoelectron spectroscopy, photoluminescence spectroscopy and photocurrent measurements show the presence of electron transfer between TiO₂ and graphene. The electron transfer between TiO₂ and graphene will greatly retard the recombination of photoinduced charge carriers and prolong electron lifetime, which will contribute to the enhancement of photocatalytic performance. Accordingly, the TOG composites show high photocatalytic activity of methyl orange under UV light, likely due to the effective separation of photoinduced charge, exposure of highly reactive {001} facets and great adsorptivity of dyes.