Visible-light-response g-C3N4@N,S-TiO2 nanocomposites for superior photocatalysis and photoelectrochemical performance

Abstract Herein, visible-light-response composites based on porous g-C3N4 nanosheets decorated with N,S co-doped TiO2 nanoparticles were constructed for photocatalytic degradation of organic pollutants and photoelectric performance. A feasible route was designed to fabricate porous g-C3N4 nanosheets with higher specific surface area and more abundant active sites. Then, visible-light-response mesoporous nitrogen and sulfur co-doped TiO2 nanoparticles were used for compounding with g-C3N4 to form the heterojunctions catalyst. Sample of g-C3N4@N,S-TiO2 with the mole ratio of 1:1 exhibited the highest photocatalytic activity in degrading of rhodamine B, which was almost 11.2 and 10.0 times as that of the pure N,S-TiO2 and g-C3N4. It was demonstrated that superoxide radicals act as the main oxidative species. Moreover, the photocurrents and EIS results verify that the molar ratio of N,S-TiO2 and CNs with an optimal value could greatly enhance the charge separation and electron transfer efficiency. The corresponding schematic diagrams have been provided to better understand the possible formation process and charge transfer mechanism. In brief, this work could provide novel insights to broadly synthesize porous g-C3N4 based composites with superior photocatalysis and photoelectrochemical performance.