Solar driven photocatalytic disinfection by Z-scheme heterojunction of In2O3/g-C3N4: Performance, mechanism and application

To realize an efficient solar disinfection, Z-scheme In2O3/g-C3N4 heterojunctions were prepared and its performances were investigated. The In2O3/g-C3N4 exhibits a wide light response range and a low carrier recombination rate. Due to the transfer of electron (e(-)) and hole (h(+)) between In2O3 and g-C3N4, the generations of superoxide (O-2(center dot-)) and hydroxyl radicals (HO center dot) were enhanced. O2 center dot - HO center dot and h(+) played important roles for disinfection. Approximately 10(6) CFU/mL E. coli were inactivated within 90 min. In addition to cell membrane lysis, DNA was degraded. In2O3/g-C3N4 still revealed high sterilization efficiencies under natural sunlight or for actual wastewater treatment. Although humic acid and inorganic anions (Cl- < NO3- < SO42- < H2PO4- < HCO3-) inhibited the disinfection, detection limit (DL, about 5.8-log removal) can be achieved. Furthermore, DL still could be achieved and the In2O3/g-C3N4 structure remained intact after 5 cycles. This study provides novel guidance for solar-driven water purification.