Synthesis and photocatalytic performance of g-C3N4/MeTMC-COP composite photocatalyst

Abstract

Covalent organic polymers have excellent application prospects in photocatalysis due to their excellent visible light absorption and structural designability. However, their fast recombination efficiency and complex preparation process limit their applications. Because of the above problems, this paper used urea to prepare g-C₃N₄ by high-temperature thermal polymerization and prepared g-C₃N₄ composite photocatalyst loaded with MeTMC-COP (g-C₃N₄/MeTMC-COP) by hydrothermal method. The photocatalytic hydrogen generation and photocatalytic degradation capabilities of composite photocatalysts with various mass ratios were investigated by characterizing the catalyst and using the organic dye Rhodamine B (RhB) as the pollutant. According to the research, the specific surface area of the g-C₃N₄/MeTMC-COP composite may reach 40.95 m² g^-1 when the mass ratio of g-C₃N₄ and MeTMC-COP is 3:1 (25.22 m² g^-1). It can offer more active sites for the photocatalytic process, and because the fluorescence peak intensity is the lowest, it has the lowest photogenerated electron-hole recombination efficiency. In comparison to g-C₃N₄, 3:1 g-C₃N₄/MeTMC-COP can breakdown rhodamine B up to 100% after 75 min of light irradiation; its photocatalytic hydrogen generation efficiency is 1.62 times that of g-C₃N₄, and the hydrogen evolution rate is 11.8 μmol g^-1 h^-1.

Keywords: covalent organic polymer; graphitic carbon nitride; hydrogen production; photocatalysis; photodegradation.