Non-metallic X (X = C, N, S, and P) co-doped copper oxide derived from Mangifera indica leaf extract: Synthesis, characterization, density functional theory simulation of structure, and photoactivities

In this study, visible light-driven non-metallic element doped copper oxide (CuO) was green synthesized using Mangifera indica leaf extract. The influences of calcination conditions such as temperature and time on the optical properties of the synthesized material are studied. The extract acts as a capping, reducing agent for the subsequent formation of non-metal doped copper oxide nanostructure and as the non-metal element source for the doping of the material. The characterization results reveal that the obtained materials take spherical shape with a size in the range of 20 and 80 nm along with the successful doping of various non-metallic heteroatoms such as carbon, sulfur, and phosphorus, in addition, the obtained materials have a low band gap energy of 1.77 eV. The electrochemical properties of the post-calcinated samples also validate the ability to hinder the recombination of charge carriers as well as the photoactivity of the materials. Density functional theory (DFT) simulation was utilized to validate the intercalation of primary heteroatom, namely, carbon into the lattice of copper oxide. The sample calcinated at a favorable temperature and time achieving an H2O2 production rate of 280.99 mM/g under visible light illumination and a removal of tetracycline efficiency of similar to 80% under sunlight. Simultaneously, the photocatalytic mechanism is proposed based on the obtained band structure of the CuO. The obtained results reveal the potential application of the green synthesized CuO nanostructure as energy carrier production as well as environmental remediation.