Copper sulfide-incorporated layered porous sulfur-doped graphitic carbon nitride nanosheets for an efficient catalytic reduction of 4-nitrophenol

Abstract

Metal sulfide-incorporated graphitic carbon nitride-based semiconductor catalysts have attracted considerable attention in the field of clean energy and environmental remediation because of their low cost, eco-friendliness, high efficiency, and ease of use. Herein, we demonstrate a facile one-pot synthesis of CuS nanoparticles in situ grown on the layered porous sulfur-doped graphitic carbon nitride nanosheets (CuS/S-g-C₃N₄), which act as a catalyst for the reduction of 4-nitrophenol. 4-Nitrophenol was reduced (converted into 4-aminophenol) by about 89.92% and 99.98% with S-g-C₃N₄ and CuS/S-g-C₃N₄ composites, respectively, within 3 min. The results demonstrate that the CuS/S-g-C₃N₄ nanohybrid composite showed superior catalytic performance compared to bare S-g-C₃N₄ due to the enhancement caused by increasing the affinity of accessible surface-active edge sites and interfacial contact allowing an effective modification of the electronic structure, high structural porosity, and richness in sulfur vacancy. Further, the fast electron transfer 4-NP reduction mechanism on CuS/S-g-C₃N₄ was explicated and discussed. Additionally, the CuS/S-g-C₃N₄ nanocomposite revealed good stability towards catalytic reduction even after repeated usage. Thus, the present study affords an in situ synthesis of CuS on the S-g-C₃N₄ nanocomposite for improving the catalytic conversion of the nitro group to the amine group.