Visible light active heterostructured photocatalyst system based on CuO plate‐like particles and SnO2 nanofibers

In this study, CuO–SnO2 p‐n type heterostructures were produced and tested for the degradation of methylene blue and 4‐nitrophenol under visible light irradiation. CuO particles were produced in plate‐like morphology using hydrothermal synthesis. SnO2 nanofibers were obtained by electrospinning. Structural, morphological, optical and semiconducting property characterization of heterostructured CuO–SnO2 and individual phases were performed. The photocatalytic activity was found to change depending on the amount of CuO particles in heterostructured samples. Among others, the sample with 0.35 wt.% CuO–SnO2 showed the highest photocatalytic efficiency with a degradation rate constant ~2 h−1. Active specie scavenger tests revealed that the decomposition reaction occurs through direct oxidation mechanism by the holes in the valence band of SnO2 in pure samples whereas in CuO–SnO2 samples ∙O2- and ∙OH radicals also form and involve in the reactions. Further, the photocatalytic degradation mechanism was revealed using relative band potentials and p‐n junctions of the heterostructured photocatalyst.