Synthesis, characterization and band alignment characteristics of NiO/SnO2 bulk heterojunction nanoarchitecture for promising photocatalysis applications

Here, we report about the development of a novel p-n bulk heterojunction semiconducting photocatalysts, made of NiO/SnO2 via microwave assisted solvothermal technique. The structure, morphology and optical properties have been characterized. It was found that the developed NiO/SnO2 heterostructure composed of face centered cubic NiO crystal structure and rutile SnO2 crystal structure. The optical band gap of this heterostructure was found to be around 3.52 eV. The photocatalysis performance was investigated based on the band bending alignment for the first time via X-ray photoelectron spectroscopy. The developed NiO/SnO2 heterostructure exhibited p-n heterojunction type-II band alignment. The photocatalysis performance of the developed bulk heterostructure was examined against methylene blue and showed promising enhancement reached to 99% owing to the efficient charge carriers separation.