ZnO decorated SnO nanosheet nano-heterostructure: a stable photocatalyst for water splitting and dye degradation under natural sunlight.

Herein, a facile hydrothermally-assisted sonochemical approach for the synthesis of a ZnO decorated SnO nano-heterostructure is reported. The phase purity of the nano-heterostructure was confirmed by X-ray diffraction and Raman spectroscopy. The morphological analysis demonstrated a nanosheet-like structure of SnO with a thickness of 20 nm, decorated with ZnO. The optical band gap was found to be 2.60 eV for the ZnO@SnO nano-heterostructure. Photoluminescence studies revealed the suppression of electron-hole recombination in the ZnO@SnO nano-heterostructure. The potential efficiency of ZnO@SnO was further evaluated towards photocatalytic hydrogen production HO splitting and degradation of methylene blue (MB) dye. Interestingly, it showed significantly superior photocatalytic activity compared to ZnO and SnO. The complete degradation of MB dye solution was achieved within 40 min. The nano-heterostructure also exhibited enhanced photocatalytic activity towards hydrogen evolution (98.2 μmol h/0.1 g) water splitting under natural sunlight. The superior photocatalytic activity of ZnO@SnO was attributed to vacancy defects created due to its nano-heterostructure.