Ce-/S-codoped TiO2/Sulfonated graphene for photocatalytic degradation of organic dyes

Abstract

TiO₂ is an abundant and environmentally benign material, but has a wide band gap, which greatly confines its applications in photocatalysis. Doping and modifying the material composition are both generally used to change and control the photocatalytic activity of semiconductors. Herein, we describe a method and resulting activity of depositing Ce-/S-codoped TiO₂ nanoparticles (NPs) on water-soluble sulfonated graphene (SGE) sheets, which guarantees a direct contact and satisfactory electron transfer between the semiconductor and graphene. The Ce/S–TiO₂ NPs are homogeneously fixed on the surface of SGE sheets with an average particle size of ∼7 nm. The resulting composite showed noticeable activity in photodegrading methyl orange (κ = 0.425 h⁻¹). This improved performance can be attributed to the synergistic effects of Ce- and S-codoping toward TiO₂ and the composite action between TiO₂ NPs and SGE. This type of novel composite is expected to stimulate the development of doped and graphene-involved photocatalysts for addressing environmental problems.