In situ fabrication of oxygen deficient Bi2MoO6/InVO4/CeVO4 dual S-scheme ternary heterostructure for robust photocatalytic H2 and H2O2 production

Abstract

Mild in situ synthesis of ternary dual S-scheme heterostructure photocatalyst with high redox ability of photo-excitons is a pragmatic approach for achieving rapid activation of tenacious atmospheric molecules. In the present study, a series of Bi2MoO6/InVO4/CeVO4 ternary heterostructures were constructed by in situ deposition of Bi2MoO6 nanoplates over one pot synthesised InVO4/CeVO4 using a facile oil bath heating method. The as-synthesised heterostructure materials were comprehensively characterised to understand their structural, optical, electrochemical and morphological properties. The ternary heterostructure displayed a distinct morphology consisting of Bi2MoO6 nanoplates, CeVO4 nanosheets and InVO4 nanorods. The significant intergrowth among the constituent phases through the in situ coupling strategy also led to the construction of tight interfacial microscopic junctions. The important attributes of the ternary heterostructures included intense photon absorption in whole UV–visible region, drastic decrease in photogenerated charge recombination and higher excited state lifetime. Both InVO4 and CeVO4 individually as well as the ternary heterostructure contained surface oxygen vacancies that further promoted efficient charge separation and activation of atmospheric molecules. The optimised ternary photocatalyst displayed 2314 μmol/g/h H2 generation and 1700 μM/g/h H2O2 production which are 12–86 and 11–27 times higher than the pristine semiconductors, respectively. Detailed band position assessment and radical entrapment analysis suggested the occurrence of a dual S-scheme charge transfer mechanism that rationally accounted for the remarkable enhancement in the photocatalytic performance.