Construction of S-scheme MnO2@CdS heterojunction with core–shell structure as H2-production photocatalyst

Artificial photosynthesis is deemed as an efficient protocol for transforming abundant solar energy into valuable fuel. In this paper, the well-defined one-dimensional (1D) core–shell MnO2@CdS hybrids were constructed by employing MnO2 nanotubes and CdS nanoparticles as nano-building blocks via a chemical co-precipitation route. The rationally designed core–shell structure provided an intimate heterojunction interface between the CdS shell and MnO2 core. All the MnO2@CdS core–shell nanocomposites possess higher H2 evolution rate through visible light irradiation contrary to pristine CdS, and the optimal MnO2@CdS hybrid exhibits the utmost H2 evolution rate of 3.94 mmol·g−1·h−1, which is 2.8-fold higher compared with that of CdS. Appertaining to XPS and Mott-Schottky (M-S) analysis, such enhanced photocatalytic H2 generation of MnO2@CdS heterojunction was ascribed to an S-scheme mechanism, which suppressed the charge recombination along with a fast detachment of electron–hole pairs (e−–h+) and significantly improved the severance of carriers, thus improved H2 evolution performance. These findings envision a new insight into the development of S-scheme heterostructure for photocatalytic H2 generation.