Mo monoatomic doping of ReS2 quantum dots with size control for piezoelectric synergistic photocatalysis

Abstract

Water purification systems based on transition metal dichalcogenides face significant challenges, including lack of reactivity under dark conditions, scarcity of catalytically active sites, and rapid recombination of photo-generated charge carriers. Simultaneously increasing the number of active sites and improving charge separation efficiency has proven difficult. In this study, we present a novel approach combining molybdenum (Mo) monoatomic doping and size engineering to produce a series of Mo-ReS₂ quantum dots (MR QDs) with controllable dimensions. High-resolution structural characterization, first-principle calculations, and piezo force microscopy reveal that Mo monoatomic doping enhances the lattice asymmetry, thereby improving the piezoelectric properties. The resulting piezoelectric polarization and the generated built-in electric field significantly improve charge separation efficiency, leading to optimized photocatalytic performance. Additionally, the doping strategy increases the number of active sites and improves the adsorption of intermediate radicals, substantially boosting photo-sterilization efficiency. Our results demonstrate the elimination of 99.95% of Escherichia coli and 100.00% of Staphylococcus aureus within 30 min. Furthermore, we developed a self-purification system simulating water drainage, utilizing low-frequency water streams to trigger the piezoelectric behavior of MR QDs, achieving piezoelectric synergistic photodegradation. This innovative approach provides a more environmentally friendly and economical method for water self-purification, paving the way for advanced water treatment technologies.

Graphical Abstract