The overall water splitting of CdS/Ti3+-SrTiO3 core–shell heterojunction via OER enhancement of MnOx nanoparticles

The OER process would be a mainly factor for restricting overall water splitting, so the matching of HER/OER would be an important issue. Herein, the MnOx/CdS/Ti3+-SrTiO3 core–shell heterojunction is fabricated via a continuous hydrothermal-annealing-chemical-photodeposition method. Evaluated by the photocatalytic performance, the MnOx/CdS/Ti3+-SrTiO3 exhibits an enhanced HER performance of about ~ 10 folds than that of pure SrTiO3 nanosphere, and achieves a decent overall water splitting performance of about ~ 176.07(H2)/86.03(O2) μmol/g∙h, which can be mainly ascribed to the well matched HER/OER process and formation of heterojunction. There, the new potential induced by Ti3+/Ov can increase the solar efficiency and accelerate the photo-generated electrons diffusion, the Ti3+ ions can reduced water splitting activation barrier to enhance the H+ reduction, the MnOx with mixed chemical valance Mn3+/Mn4+ ions can activate the hole­related species and promote the H2O2 decomposition, and the core–shell CdS/Ti3+-SrTiO3 heterojunction with appropriate potential gradient can improve the charge carrier separation and transport. Additionally, the core–shell structure can inhibit the photocorrosion to maintain good photocatalytic stability.