Construction of Quantum Well surface from an Nb Surface doped Core-shell La-SrTiO3 Nanocubes for Photocatalytic Hydrogen Production

Perovskite oxide semiconductors represent as one of the most promising photocatalysts for water splitting for hydrogen production; however, they still suffer from low light harvesting efficiency and low quantum yield. Here, an interfacial super-assembly towards nanoscale quantum well core-shell structure is demonstrated as a conceptual novel strategy for the design of high-performance perovskite oxide photocatalyst. A quantum well core-shell structure composed of La-doped SrTiO 3 core and Nb-doped SrTiO 3 surface is synthesized. Experimental and theoretical simulation demonstrate that the Nb-doped shell with a thickness of ~ 1 nm enables a lower conduction band potential and the formation of quantum confinement effect on the surface, in which the excited electron can be excited from the La-doped SrTiO 3 core to the Nb-doped surface and confined on the 2D Nb-doped surface for highly efficient electron-hole pair separation. The quantum well SrTiO 3 (QW-SrTiO 3 ) nanocubes exhibit a strong visible light absorption and remarkably prevent the recombination of photogenerated electron-hole pair through the surface quantum confinement effect. Using graphene (GR) as the electron acceptor, the quantum well SrTiO 3 nanocubes display the highest photocatalytic H 2 production rate of 14.69 mmol h − 1 g − 1 , which is 78 times higher than that of pristine SrTiO 3 nanocubes. Furthermore, QW-SrTiO 3 /GR hybrid also shows excellent stability for hydrogen evolution. The quantum well designed on the SrTiO 3 nanoparticles provides an insight for creating novel photocatalysts to tackle environmental and sustainable energy issues.