A Z-scheme heterojunction of ZnO/CDots/C3N4 for strengthened photoresponsive bacteria-killing and acceleration of wound healing

The abuse of antibiotics is leading to the emergence of resistant bacteria. In this work, a drug-free composite of ZnO/CDots/g-C3N4 with Z-scheme heterojunction was developed, which was employed to kill bacteria effectively within a very short time under the irradiation of visible light due to the enhanced photocatalytic and photothermal effects. In this system, the CDots acted as a bridge between g-C3N4 and ZnO, effectively inhibiting the recombination of photo-generated electrons with holes and consequently enhancing the photocatalytic properties. In addition, CDots endowed the system with excellent photothermal effects. As a result, the antibacterial efficacy of ZnO/CDots/g-C3N4 composite against S. aureus and E. coli reached up to 99.97 % and 99.99 % respectively, after 15 min of visible light irradiation, due to the synergistic action of photo-inspired radical oxygen species and hyperthermia. The Zn ions released from the composite promoted the growth of fibroblasts, which accelerated the wound healing process. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.