Dual Regulation of Piezocatalysis in Metal-Doped MoS₂: Linking Piezoelectric Coefficient and Electronic Structure

Doping is a recognized strategy to enhance the piezocatalytic performance of MoS₂, but how to simultaneously regulate piezoelectric and electronic properties for efficient charge separation and utilization remains unclear. Here, we systematically compared transition-metal (Mn, Fe, Co, Ni, Cu) and rare-earth (La, Ce) dopants in MoS₂ to elucidate their dual regulatory roles in piezocatalysis. Doped MoS₂ samples were synthesized via a solvothermal method and comprehensively characterized to reveal morphological evolution, phase modulation, and lattice distortion. Piezoresponse force microscopy confirmed enhanced piezoelectric responses in all doped samples; however, the catalytic activity, reflected by MTX degradation, did not follow the same order, indicating that piezoelectric coefficient (d₃₃) enhancement alone does not ensure superior performance. Density functional theory calculations revealed that dopants modulate the Mo d-band center, thereby tuning the adsorption energetics and charge utilization. Among the dopants, Co achieved the best balance of the piezoelectric response, d-band center position, and 1T-phase stabilization, leading to superior catalytic activity. This comparative study establishes a clear structure-property-activity relationship and provides guidance for rational dopant screening in the design of high-performance piezocatalysts.