Construction of Co-doped NiS/S-g-C3N4 heterojunction for boosting degradation of dye and inactivation of pathogens in visible light

Constructing well-defined heterojunction especially the one-dimensional/two-dimensional (1D/2D) is promising but still challenging for enhanced photocatalytic activity. In this work, I constructed a sequence of novel 1D/2D heterojunction nanocomposites (NCs) by the coupling of S-g-C3N4 nanosheets (NSs) with different quantities (1, 2, 3, 4 and 8 wt%) of 1D Co-doped NiS nanorods (NRs). A unique 1D/2D heterojunction designed between CNS and S-g-C3N4 produces abundant catalytic active sites and a vast number of heterojunctions for photocatalytic methylene blue (MB) degradation. The as-fabricated samples were evaluated by leading-edge techniques such as XRD, SEM, EDX, TEM, FTIR, XPS, UV-vis, BET, PL and transient photocurrent. Our results explored that the intimate interface contact between CNS NRs and S-g-C3N4 was probed via surface loading of CNS NRs on S-gC(3)N(4) NSs, enhancing the generation, separation and transportation of photogenerated electron/hole pairs and preventing the recombination of photoinduced charge carriers. When employed as photocatalysts to degrade MB under visible light illumination, 3CNS-10-SCN displayed the maximum removal rate (99%), substantially boosted than that of NiS NRs (35%), 3% CNS NRs (56%) and S-g-C3N4 (32%). Meanwhile, the photo-corrosion of S-gC(3)N(4) was suppressed by synchronized coupling with CNS NRs and doping with Co, which was proved by a structural stability experiment with six repeated runs. Such extraordinary improvement in photocatalytic performance and stability was mainly credited to active separation and transportation of photoinduced electronhole pairs at the 3CNS-10-SCN heterojunction. Antibacterial activity of 1D/2D 3CNS-10-SCN NCs against 4 bacterial species was estimated by illumination of Vis-light.