Rational strategy for the construction of Z-scheme based MoS2/Co3O4 coupled SrTiO3 nanocomposite for dye degradation: An experimental and theoretical insights

Z-scheme Co3O4/MoS2/SrTiO3 (CMS) highly efficient ternary photocatalyst was prepared by facile wet impregnation method. The Density Functional Theory (DFT) calculations and various properties like microstructure, optical, functional, elemental, surface, and compositional formation of the prepared samples were studied. In the effect of Co3O4/MoS2 (CM) into the SrTiO3 (ST) sample, the photocatalytic performances were ultimately enhanced due to successful heterojunction formation of synergistic effects, improved light absorption ability, suitable band positions, and increased charge separation efficiency with the Z-scheme charge transfer process. In addition, the optical bandgap was tuned from 3.25 eV to 2.86 eV, which could effectively improve the photocatalytic performance under UV–vis. light. The synthesized CMS photocatalyst achieved the topmost degradation efficiency of 95 % over methylene blue (MB) dye in 100 min under UV–vis. light irradiation. The degradation rate constant was estimated at 0.0275 min−1, which is 4.9 folds higher than other synthesized photocatalysts. The different reactive species for degradation activity were determined by scavenger experiments. The stability and reusability of the CMS photocatalyst were identified after 4 consecutive runs of the recycle experiment. This work brings forth a new insight into designing ternary photocatalysts with rapid e− transfer by a Z-scheme photocatalytic mechanism for efficient organic dye degradation.