Mo-doped CdS: optimized electronic structure boosts carrier separation

Abstract

CdS-based photocatalytic materials exhibit considerable potential for the degradation of organic pollutants and energy conversion; however, the propensity for photogenerated charge carriers to recombine poses a significant limitation to the enhancement of their photocatalytic efficiency. This study investigates the modification of CdS through Mo doping, with the objective of optimizing its electronic structure and photocatalytic activity. Comprehensive characterization of the crystal structure and morphology of Molybdenum-Doped CdS was conducted using XRD, XPS, and SEM. The results indicated successful incorporation of Mo into the CdS lattice, resulting in the formation of smaller nanospherical structures that significantly increased the specific surface area and active sites. Photocatalytic experiments demonstrated that Mo-CdS/8 exhibited the highest catalytic activity in the degradation of TC, achieving a removal efficiency of 98.8%, which was 1.5 times greater than that of undoped CdS. Additionally, photoelectric current response testing and EIS analyses further revealed that Mo doping effectively enhanced the separation efficiency of photogenerated charge carriers and reduced the likelihood of carrier recombination. DFT calculations indicated that Mo doping introduced impurity energy levels into the band structure, thereby broadening the spectral response range of the material. This study substantiated that appropriate Mo doping not only enhanced the photocatalytic degradation efficiency of CdS but also significantly mitigated the generation of toxic byproducts, thereby presenting substantial practical application potential. These findings provided a crucial theoretical foundation and practical references for the modification and design of CdS-based photocatalytic materials.