Single-Atom Engineering and Phase-Transition Optimization in MoS2 for Enhanced Schottky Junction Piezocatalysis

Molybdenum disulfide (MoS₂) has attracted considerable attention as a piezocatalyst due to its distinctive piezoelectric properties and potential for environmental remediation. However, its practical application is limited by the metastability of the 1T phase and inconsistent doping, which result in nonuniform Schottky barrier heights and inefficient charge transfer, ultimately restricting catalytic performance and long-term stability. In this study, we developed a high-performance piezocatalyst by designing a hybrid-phase MoS₂ Schottky junction, comprising both 1T and 2H phases, and incorporating cobalt single atoms (Co-T/H MoS₂). The introduction of Co single atoms enhances the piezoelectric properties through local structural distortions induced by Co-S covalent bonding. This incorporation also promotes the formation of the 1T phase in MoS₂, increasing the density of Schottky junctions, which effectively reduces electron backflow and improves charge separation. Furthermore, the piezoelectric polarization of 2H MoS₂ lowers the Schottky barrier, facilitating electron transfer to the 1T phase. The resulting Co-T/H MoS₂ achieves a reaction rate of 1.08 min^-1 for ciprofloxacin (CIP) degradation, which is 15.9 times higher than the 0.068 min^-1 rate observed for bare 2H MoS₂. This superior degradation efficiency is attributed to the high density of Schottky junctions, which enhance oxygen activation and promote the generation of superoxide radicals (•O₂^-), crucial for CIP removal. These findings provide valuable insights into piezocatalytic mechanisms and underscore the potential of designing efficient piezocatalysts for practical environmental applications.