Robust and reusable near-infrared photocatalyst derived from SnO2 quantum dots-decorated MXene for rapid water disinfection

The lack of universal access to microbiologically safe water is a serious global concern. Photocatalytic water disinfection has demonstrated significant promise due to its accessibility and high energy efficiency. This study introduces tin dioxide (SnO 2 ) quantum dots (QDs)-decorated Ti 3 C 2 T x (SnO 2 QDs/Ti 3 C 2 T x ), which achieves broad-spectrum microbial inactivation, with a reduction of > 6-log within 5 min under 808 nm near-infrared (NIR) light irradiation. This performance is attributed to the reactive oxygen species that are generated following the introduction of the SnO 2 QDs to Ti 3 C 2 T x , which reduces the charge-transfer resistance and thus facilitates charge separation. To explore the application potential of the proposed photocatalytic system, a SnO 2 QDs/Ti 3 C 2 T x -loaded hydrogel is developed. This hydrogel exhibits durable, broad-spectrum antimicrobial efficacy, and applicability for practical water disinfection under 808 nm NIR light. This study describes a simple and rapid approach to water disinfection, thus potentially promoting global access to safe water.