The influence of n-type and p-type dopants on the interfacial charge transfer and the band structure of Bi2MoO6 to enhance solar H2 production

Abstract

NiO and CdS loaded Bi2MoO6 nanocompositephotocatalysts were synthesized by using hydrothermal method followed by an impregnation method. The performances of the synthesized materials were evaluated for H2 production under direct solar light irradiation.Among the synthesized catalysts, 1 wt% NiO/CdS-Bi2MoO6 showed the highest H2 production.The characterization results revealed that the porous and orthorhombic structure of Bi2MoO6. The heterojunctions at the interfaces of NiO(p-type) and CdS(n-type) nanocrystals with Bi2MoO6(n-type) nanoparticles were revealed by HRTEM images.The n-n and p-n type junctions at the interfaces of the nanocrystals played very important roles to improve the interfacial charge transfer (IFCT) and to extend the life time of the photogenerated charge carriers, these phenomena were confirmed by the photoelectrochemical and photoluminescence studies. The donor (n-type) and acceptor (p-type) dopants on Bi2MoO6significantly reduced the band gap and shifted the light absorption edge position to longer wavelength than the single doped materials, which was confirmed by DR UV–vis spectroscopy. Hence,the favourable characteristic changes on Bi2MoO6created by the presence of both NiO and CdSsynergistically enhanced the rate of H2 production 3 times higher than that of the pristineBi2MoO6.This work provides aprofundity on the development of solar light responsive Bi2MoO6 based photocatalysts for H2 production.