Facile fabrication of 2D-2D g-C3N4/Sb heterojunction with enhanced photocatalytic degradation activity of methylene blue

A novel and efficient photocatalyst g-C3N4/Sb was constructed by impregnating graphitic carbon nitride with 2D antimonene in this study. XRD, SEM, FT-IR and XPS results all confirmed the successful construction of g-C3N4/Sb heterojunction. Inhibited recombination of photogenerated electron–hole pairs and enhanced photocatalytic activity are observed for the composited sample. Under light irradiation, the composite shows a three-fold increased degradation rate for methylene blue. The reaction efficiency retains about 92.4% after three test cycles, suggesting great stability of the catalyst. Meanwhile, photoelectrochemical test results show that the overpotential for oxygen evolution reaction is lowered to 322 mV and the photocurrent response is elevated by six times for g-C3N4/Sb compared to pristine g-C3N4. It is concluded that the junction between 2D antimonene and g-C3N4 provides a channel for the high-speed transfer of photogenerated carriers, which helps to improve photocatalytic performance. This work provides a new way to construct the two-dimensional heterojunction based on g-C3N4 for improved catalytic performance.