3D Interwoven SiC/g-C3N4 Structure for Superior Charge Separation and CO2 Photoreduction Performance

Abstract

To address the limitations of carbon nitride in photocatalysis, we propose constructing a three-dimensional interwoven SiC/g-C₃N₄ composite structure. Utilizing the strong microwave-thermal conversion characteristics of SiC whiskers, localized “hot spots” are generated, which induce rapid thermal gradients, promoting rapid polymerization of urea and in situ formation of the interwoven network. This unique structure strengthens the interaction between these two components, creates multiple electron transport pathways, enhances CO₂ adsorption, and effectively improves charge separation while reducing photogenerated carrier recombination. The CO generation rate of the composite catalysts under simulated sunlight approaches 17.78 μmol g^–1h^–1 with 93.28% selectivity, three times more than pure g-C₃N₄. These findings offer innovative strategies for designing multiscale structures to enhance CO₂ photocatalytic reduction. They also contribute to the development of sustainable catalysts for energy and environmental applications.