Photothermal–Photocatalytic Ternary Heterostructure for Solar Light-Driven Highly Efficient Degradation of Antimicrobial Agents and Inactivation of Superbugs

A significant proportion of antimicrobial agents, such as different antibiotics discharged into the environment via human and animal waste, poses significant problems for ecological balance and human health. Moreover, widespread overuse and misuse of antibiotics have led to antibiotic-resistant bacteria (superbugs), which is one of the biggest global health problems in the 21st century. Since the utilization of solar energy, which is an abundant and natural resource for the photocatalytic system, we report the design of a photothermal–photocatalytic dual-functional light absorber-based ternary heterostructure using plasmonic gold nanoparticle (AuNP)-anchored WO3 nanoplatelet (WO3 NPL)-decorated reduced graphene oxide (r-GO) (AuNP/WO3 NPL/r-GO), which exhibits strong absorption between 400 and 900 nm regions and has the capability for the sunlight-driven 100% degradation of doxycycline antibiotics. Herein, we show that due to the excellent photothermal performance of AuNP and r-GO in the heterostructure, the local temperature increased under 785 NIR nm light irradiation, which boosted the photocatalytic degradation reaction kinetics for doxycycline antibiotics via enhancing the transfer of "hot carriers" and the formation of reactive oxygen species (ROS). Furthermore, experimental data indicate that by integrating photothermal–photocatalytic materials, sunlight can be used for 100% doxycycline antibiotic degradation after 80 min of light irradiation. Moreover, we demonstrate that the ternary heterostructure can be used for sunlight-based 100% inactivation of carbapenem-resistant Enterobacteriaceae Escherichia coli (CRE E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) superbugs by just exposing them to light for 60 min. This study sheds light on the construction of photothermally assisted photocatalytic ternary heterostructures for high-efficiency sunlight-driven degradation of antibiotics and superbugs.