Effective strategy of incorporating Co3O4 as a co-catalyst onto an innovative BiVO4/Fe2TiO5 core-shell heterojunction for effective photoelectrochemical water-splitting application

In the realm of photoelectrochemical (PEC) water splitting, core-shell heterojunction followed by catalyst loading over the photoelectrodes are known to speed up both separation and injection of photogenerated charge carriers. In this work we have reported the fabrication of BiVO4/Fe2TiO5/Co3O4 photoelectrodes through simple chemical routes. The fabricated photoelectrodes have been confirmed through different structural, morphological and optical analysis. Stepwise introduction of Fe2TiO5 as shell loaded with catalyst Co3O4 enhance the parameters like separation and injection efficiency of BiVO4 based photoanodes respectively. The effect of formation of the heterojunction followed by immobilization of loaded catalysts results in 5.3 folded highest photocurrent density with remarkable cathodic shift than bare BiVO4 photoanodes in a neutral electrolytic condition. Along with this it has been found that apart from heterojunction formation there in the creation of the oxygen vacancies which is also responsible to produce cumulative effect of the charge separation and injection of the photoanodes. Finally different PEC characterizations such as (a) flat band estimation, (b) study of charge transfer resistances and capacitances along with band structure analysis proved that proposed BiVO4/Fe2TiO5 core-shell heterojunction loaded with the catalyst Co3O4 possess n-n-p staggered type-II configuration.