A highly efficient (Mo, N) codoped ZnIn₂S₄/g-C₃N₄ Z-scheme photocatalyst for the degradation of methylene blue

Fabricating a Z-scheme heterostructure is an effective strategy for the highly efficient photocatalyst. However, the conscious modulation of Z-scheme charge transfer is still a great challenge. Herein, Mo, N (co) doped ZnIn₂S₄/g-C₃N₄ nanosheets are successfully synthesized by a sol–gel method. The systematic investigations show that the heterostructure construction and codoping can extend the optical absorption edge and provide more active sites. More importantly, the separation and transfer of photoinduced electron-hole pairs are greatly improved between (Mo, N) codoped ZnIn₂S₄ and g-C₃N₄ by the photoelectrochemical and PL spectra results, and forming a Z-scheme charge transfer mechanism in the (Mo, N) codoped ZnIn₂S₄/g-C₃N₄. Under the intense synergy among the internal electric field of heterostructure and (Mo, N) codoping, the optimized (0.35% Mo, 2.4 % N) codoped ZnIn₂S₄/g-C₃N₄ Z-scheme photocatalyst exhibits an outstanding photocatalytic activity and cyclic stability for methylene blue degradation with the visible light illumination, The degradation rate of (Mo, N) codoped ZnIn₂S₄/g-C₃N₄ reaches to 97% after 120 min irradiation, which is 1.3 and 2.6 times higher that of ZnIn₂S₄/g-C₃N₄ and ZnIn₂S₄, respectively. These codoping atoms modulation strategy of Z-scheme charge transfer presents a facile and promising pathway to enhance photocatalytic activity.