High-temperature sulfurized synthesis of MnxCd1−xS/S-kaolin composites for efficient solar-light driven H2 evolution

To extend the application of kaolin in solar-light induced water splitting, MnS-CdS solid solution modified S-doped kaolin (MnxCd1−xS/S-kaolin) composites were in-situ prepared via the high-temperature sulfurization. Compared with kaolin and S-doped kaolin, MnS and CdS greatly enhanced H2 evolution rate, especially MnxCd1−xS. H2 evolution rate was affected by Mn/Cd molar ratio, Mn0.5Cd0.5S content, and sulfurized temperature. The optimal 4-Mn0.5Cd0.5S/S-kaolin with a Mn/Cd molar ratio of 1:1 and a nominal Mn0.5Cd0.5S content of 28% treated at 823 K could obtain the highest H2 evolution rate (4955.27 μmol g−1 h−1), which was 49.33 and 25.28 folds higher than kaolin and S-doped kaolin, respectively. H2 evolution capacity of 4-Mn0.5Cd0.5S/S-kaolin decreased from 24,476.79 to 24,262.35 μmol g−1 after five cycles. It’s ascribed to the tight interface among S-doped kaolin, MnS and CdS for the efficient transfer and migration of photo-excited charges, and the sufficient active sites formed in S-doped kaolin and S-defected Mn0.5Cd0.5S were suitable for the efficient photon utilization and visible-light harvesting. [Display omitted] •MnxCd1−xS/kaolin was prepared via high-temperature sulfurization.•H2 evolution rate of optimal Mn0.5Cd0.5S/kaolin was 4955.27 μmol g−1 h−1.•The tight junction interface favored the transfer and separation of charge carriers.