One-Pot Synthesis of Highly Dispersed VO2 on g-C3N4 Nanomeshes for Advanced Oxidation

Advanced oxidation catalyzed by metal oxides is a promising approach for degrading organic pollutants in wastewater. A critical strategy to enhance the performance of these catalysts is optimizing the dispersion of their active components through innovative synthesis methods. In this study, we report a one-pot synthesis of g-C3N4nanomeshes supported with highly dispersed VO2catalysts (V-g-C3N4) for the advanced oxidation of methylene blue (MB). The characterization results reveal that the involvement of VCl3in the pyrolysis of melamine facilitates the formation of g-C3N4nanomeshes with abundant amino groups (NH/NH2). The strong interaction between vanadia species and amino groups prevents VO2particles from agglomerating, resulting in a significantly higher vanadia dispersion than V-g-C3N4-im synthesized via the traditional impregnation method. V-g-C3N4exhibits a sophisticated microstructure and surface structure, which leads to a rate constant 2.3-fold higher than V-g-C3N4-im in the catalytic degradation of methylene blue using H2O2as the oxidant. X-ray photoelectron spectroscopy, trapping experiments, and electron paramagnetic resonance measurements reveal that the rapid adsorption and fast diffusion of MB over g-C3N4nanomeshes, together with the efficient H2O2activation into ·OH radicals via the V4+/V5+redox cycle, synergistically contribute to the superior MB removal efficiency of V-g-C3N4. Moreover, V-g-C3N4demonstrates no significant decrease in activity even after the fourth cycle, indicating its excellent stability during the pollutant removal process.