Microtubular Nanoporous g-C3N4@Ag as an Efficient Photocarrier Transfer Agent and Visible Light-Harvesting for Photodegradation of Methylene Blue

Abstract

Microtubular nanoporous graphitic carbon nitride@silver (MN-g-C3N4@Ag) was synthesized in order to investigate the efficiency of a photocarrier transfer agent and visible light-harvesting to improve the applicability of photocatalytic reactions in solving the environmental pollution problem. The content of AgNPs was optimized, and MN-g-C3N4 with 5% of Ag shows the best performance. The results indicated that Ag nanoparticles were homogeneously distributed onto the MN-g-C3N4 surface, which leads to the absorption and harvesting of more visible light on the catalyst. The statistical analysis of the experimental data showed that the kinetic model and the adsorption isotherms for the surface adsorption process are consistent with the Langmuir isotherm [Qmax = 272.0 (mg g–1)] and the pseudo-second-order kinetics [Qe.cal = 280.0 (mg g–1)]. Also, the kinetic rate constant of photocatalytic degradation for the MN-g-C3N4@Ag photocatalyst is 7.5 times higher than that of MN-g-C3N4 and 59.0 times higher than that of bulk g-C3N4. Also, the mechanism of photocatalytic degradation showed that holes and •O2– are the main species for photocatalytic degradation of MB through surface adsorption. As a result, the MN-g-C3N4@Ag nanocomposite can use silver metal as both a Schottky barrier and plasmonic effects generator and MN-g-C3N4 itself as a porous photocatalyst with unique charge transfers in the axial direction. Which can synergistically be prolonged lifetime and photocarrier diffusion length, proving that MN-g-C3N4@Ag can efficiently be operated in environmental pollutant remediation.