Solar-light-driven rapid water disinfection by ultrathin magnesium titanate/carbon nitride hybrid photocatalyst : Band structure analysis and role of reactive oxygen species

Novel and cost-effective Z-scheme 2D/2D MgTi₂O₅/g-C₃N₄ hybrid was synthesized by in situ growth of MgTi₂O₅ on the g-C₃N₄ nanosheets. The photocatalytic activity of as-prepared hybrid was investigated using bacteria disinfection. The results indicated that the composite exhibited enhanced E. coli inactivation under visible light (VL) irradiation, with the complete inactivation of 7 log10 cfu/mL of cells reduction within 3 h, while the pristine g-C₃N₄ and MgTi₂O₅ almost showed no cell reduction under the same condition. The destruction of bacterial cell was investigated by fluorescence microscopic images and transmission electron microscopy analysis. The optimum photoactivity could be attributed to 1) the short charge transport distance and large interface contact area of the 2D/2D structure, 2) the efficient charge separation and spatially separated reductive and oxidative active sites originated from Z-scheme system. This work could shed lights on the design and fabrication of 2D/2D Z-scheme system for VL driven water disinfection.