Photothermal synergistic effect of Ti3C2Tx/ZnIn2S4 Schottky junction for efficient inactivation of antibiotic-resistant bacteria and genes: Mechanism discussion and practical application

Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) in wastewater pose a significant threat to public health. Photothermal synergistic catalysis has the great potential to effectively mitigate ARB and ARG pollution. Herein, we design a Ti3C2Tx/ZnIn2S4 (Ti3C2Tx/ZIS) Schottky junction with photothermal effect by exploiting the contact potential difference between Ti3C2Tx and ZnIn2S4. The experimental results and DFT calculations demonstrate that the Schottky barrier inhibits electron backflow, thereby enhancing the photody-namic properties of Ti3C2Tx/ZIS. The photothermal heating effect, induced by the localized surface plasmon resonance (LSPR) of Ti3C2Tx, further enhances ROS production via facilitating charge transfer. Profiting from the photothermal synergistic effect, Ti3C2Tx/ZIS can completely inactivate ARB within 25 min and degrade 5-log ARG within 120 min under vis-NIR light irradiation. The Ti3C2Tx/ZIS demonstrated its potential for practical wastewater treatment in a flow-through reactor process, achieving 4-log bacteria inactivation and 99.7% ARG removal from secondary effluent after continuous operation for 8 h.

Automated summary

By designing a Ti3C2Tx/ZnIn2S4 Schottky junction with photothermal effect, the pollution of antibiotic-resistant bacteria and antibiotic-resistant genes can be effectively mitigated. The Schottky barrier inhibits electron backflow and enhances the photodynamic properties of Ti3C2Tx/ZIS. The localized surface plasmon resonance induced photothermal heating effect further enhances ROS production. The Ti3C2Tx/ZIS can completely inactivate antibiotic-resistant bacteria and degrade antibiotic-resistant genes under visible-near infrared light irradiation. Continuous operation in a flow-through reactor demonstrates the potential of Ti3C2Tx/ZIS for practical wastewater treatment.