In-situ construction of Schottky junctions by highly dispersed Ni co-catalysts supported on mesoporous defective t-TiO2 for boosting photocatalytic H2 evolution

Abstract

Designing photocatalysts with interfacial design and defect engineering are crucial to improved H2-evolution efficiency of photocatalytic water splitting. Herein, mesoporous tablet-like x-wt% Ni/t-TiO2 catalysts with Schottky junction and oxygen vacancies (Oν) were constructed using metal–organic framework (namely MIL-125(Ti)) as template. It is demonstrated that the optimal composition of 1 wt% Ni/t-TiO2 achieves a H2 production rate of 4276.13 μmol/g/h without using noble metal Pt. It was ∼129 times higher than MIL-125(Ti) derived pure TiO2 (t-TiO2) and showed fair durability after least four consecutive cycles test under full spectrum light irradiation. Particularly, its apparent quantum efficiency (AQE) at 350 nm reaches 12.09 %. Our results show that the synergetic effect of Schottky junction and oxygen vacancies (Oν) contribute significantly to the high catalytic performance. Meanwhile, the mesoporous structure provides a large specific surface area which is crucial for further enhancement of the reaction rate. This work opens an effective and low-cost strategy for preparing novel heterojunction photocatalysts with abundant oxygen vacancies and improving the hydrogen generation rate of MOF-derived photocatalysts without using noble metal.