Designing multi-functional MoS2/rGO piezocatalysts based on bacteria-catalyst topological interactions and electron pump effects for efficient water disinfection

Abstract

In catalytic technology, the capability of nanocatalysts to generate reactive species (ROS) and the rapid contact between ROS and target pollutants are critical for the catalytic reaction. Herein, we proposed an effective strategy to construct multi-functional MoS2/rGO piezocatalysts based on bacteria-catalyst topological interactions and electron pump effects, which possessed high carrier separation ability and adhesion to bacteria, ensuring the effective utilization of ROS. Attributed to the unique 3D heterogeneous structure and interface electronic structure, MoS2/rGO could completely inactivate 6.21 log10 cfu mL−1 of E. coli K-12 within 30 min under ultrasonic conditions, significantly faster than pure MoS2. It was demonstrated experimentally and theoretically that the introduction of rGO led to the generation of a large amount of ROS by enhancing the piezoelectric properties and conductivity of MoS2/rGO, while the topological interactions between MoS2/rGO and bacteria facilitated effective bacteria capture, improving the utilization of ROS. Additionally, Kelvin Probe Force Microscopy texting confirmed that rGO acts as an electron pump, effectively attracting electrons from bacterial cells, which disrupted bacterial metabolic processes, increased oxidative stress, and further enhanced the bactericidal effect. The mechanisms of topological interactions and electron pump effects elucidated in this work offer new insights into the design and understanding of efficient bactericidal materials in water purification applications.