Well-controlled SrTiO3@Mo2C core-shell nanofiber photocatalyst: Boosted photo-generated charge carriers transportation and enhanced catalytic performance for water reduction

In artificial photocatalysis for hydrogen (H-2) generation from water reduction, low apparent quantum efficiency (AQE) always confines the photocatalytic conversion efficiency. Here, we demonstrate a new strategy for the design and synthesis of one-dimensional (1D) SrTiO3@Mo2C core-shell nanostructure for highly enhanced photocatalytic H-2 generation activity. The thin nanolayer of Mo2C improves the interfacial conductivity, facilitates transport of photo-generated charge carriers as well as prolongs charge carriers' lifetime, that minimizing the recombination of photo-generated electrons and holes. Thus SrTiO3@Mo2C hybrid achieves drastically enhanced photocatalytic H-2 generation rate up to 7.93 mmol h(-1) g(-1) with respect to the pristine SrTiO3 (0.53 mmol h(-1) g(-1)) in a solar-driven reaction system, with an AQE of 29.3% at 313 nm. The charge carrier dynamics based mechanism was further confirmed by analysis of time-resolved photoluminescence (TRPL), surface photovoltage (SPV), transient photovoltage (TPV), open circuit potential (OCP) decay curves as well as the electrochemical impedance spectroscopy (EIS) measurements. It is unambiguously to demonstrate that Mo2C is a highly active cocatalyst to dramatically boost the charge separation for photocatalytic water reduction.