g-C3N4 quantum dots-modified mesoporous TiO2–SiO2 for enhanced photocatalysis

The utilization of TiO2-based photocatalysts for an efficient removal of dye pollutants is limited due to their low surface area, high recombination rate of the photo-generated electrons and holes and an insufficient absorption of sunlight with only 3–4% use of solar energy. Based on this background, we have successfully fabricated a carbon nitride quantum dots (CNQDs)-modified mesoporous TiO2–SiO2 (Me-TSCN) via a simple calcination method since the mesoporous structure is expected to induce a great increase in the specific surface area by carbon nitride quantum dots, being favorable for the adsorption of the reactant molecules and the mass transfer of the reaction products. Furthermore, such CNQD modification facilitates the separation of photo-generated electrons and holes. As a result, the composite's modification with structural design could significantly improve the photocatalytic activity of TiO2-based catalysts, achieving outstanding photocatalytic activity in the degradation of dye pollutants such as rhodamine B.