Morphology Adjustment of Pure and Doped g-C3N4 by Mercapto Group-Induced Assembly Towards Enhanced Photocatalysis

Graphitic carbon nitride (g-C3N4) nano-materials with different morphologies were prepared in this study by two-steps through controlling the mercapto group-induced assembly. Mercaptopropyl trimethoxysilane (MPS)-decorated SiO2 nanospheres were employed as hard templates to produce g-C3N4 in the first step. Different morphologies of g-C3N4, such as hollow spheres, nanotubes and quasi-belts, were created in the second step by controlling the concentration of etching agents, reaction time, and process. During the etching process, the mercapto groups in MPS can induce the assembly of g-C3N4 and play a crucial role of tuning the morphologies of g-C3N4, which is the key point for morphology adjustment. To enhance photolysis activity, cobalt-, boron-, and carbon-doped g-C3N4 were further prepared to tune the band gap and absorption in visible light. The morphologies of doped samples changed after doping. In addition, carbon self-doped g-C3N4 exhibited the best photo-redox activity due to increased visible light absorbance, electrical conductivity, and narrow band gap.