Graphitic carbon nitride nanosheets decorated with TiO2 mesocrystals for visible-light photodegradation of rhodamine B

Abstract

TiO2 mesocrystals (M-TiO2) can promote the adsorption of organic pollutants and provide effective conduction pathways for the photogenerated charge carriers. However, the pristine M-TiO2 had no visible-light absorption due to its wide band gap. In this paper, the hollow-box-structured mesoscopic TiO2/g-C3N4 (M-T-CN) composites with visible-light response were prepared by liquid phase deposition (LPD) and topological transformation. The results showed that the sample of M-T-CN-300 can degrade 99.1% Rhodamine B (RhB) solution within 15 min under illumination. The reaction rate constant of M-T-CN-300 was nearly 3 times and 34 times that of pristine g-C3N4 and M-TiO2, respectively. Photoluminescence (PL) analysis confirmed that the coupling of M-TiO2 and g-C3N4 can reduce the recombination of photogenerated charge carriers. The enhanced photocatalytic performance in M-T-CN composite material was mainly attributed to the synergistic effect of M-TiO2 and g-C3N4, which can effectively promote the separation of charge carriers and achieve the visible-light absorption.