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. Herein, a 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 SrTiO3 core and Nb-doped SrTiO3 surface is synthesized. Experimental and theoretical simulation demonstrate that the Nb-doped shell with a thickness of similar to 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 SrTiO3 core to the Nb-doped surface and confined on the 2D Nb-doped surface for highly efficient electron-hole pair separation. The quantum well SrTiO3 (QW-SrTiO3) 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 SrTiO3 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 SrTiO3 nanocubes. Furthermore, QW-SrTiO3/GR hybrid also shows excellent stability for hydrogen evolution. The quantum well designed on the SrTiO3 nanoparticles provides an insight for creating novel photocatalysts to tackle environmental and sustainable energy issues.

Automated summary

This research proposes a novel nanoscale quantum well core-shell structure for the design of high-performance perovskite oxide photocatalysts. The structure utilizes a Nb-doped quantum well on SrTiO3 nanoparticles to achieve efficient separation of photogenerated electron-hole pairs, showing strong visible light absorption and prevention of recombination of electron-hole pairs.