Rational Construction ZnO@C₃N₄ Composite with Enhanced Photocorrosion-Resistance for Simultaneous Removal of RhB-MO Mixed Pollutants

A series of ZnO@C(3)N(4 )composites with excellent photocorrosion-resistant and photocatalytic activity were prepared by using one-pot calcination synthesis for the removal of organic pollutants from wastewater. Compared with ZnO and C3N4, ZnO@C3N4 presented the excellent photocatalytic performance for RhB, MO, DBP and RhB-MO mixed systems under UV conditions. The degradation rate constants of 70ZnO@30 C3N4 for RhB and DBP were 7.66 and 4.71 times higher than those of ZnO, respectively. For RhB-MO mixed systems, the rate constant was 4.65 times higher than that of RhB alone. XRD and FTIR analyses indicated a strong phase interaction between two components of ZnO@C3N4 composites. XPS results confirmed the formation of ZnO/C3N4 heterojunction. In addition, the mechanisms underlying the highly efficient catalytic performance of ZnO@C3N4 composites in the degradation of organic pollutants were also analyzed. It can be attributed to the fact that a tight contact at the interface and well-matched band edge position between ZnO and C3N4 can effectively separate and transfer photoinduced carriers for organic pollutant degradation, rather than react with ZnO itself. This study clearly demonstrates a simple way to fabricate ZnO@C3N4 with photocorrosion-resistant and to apply them for the removal of multi-component organic pollutants from wastewater by photocatalysis.