High-efficiency sono-solar-induced degradation of organic dye by the piezophototronic/photocatalytic coupling effect of FeS/ZnO nanoarrays.

Highly-efficient sono-solar-induced degradation of organic dye by the piezophototronic/photocatalytic coupling effect of FeS/ZnO nanoarrays was achieved. A steel screen was used as the substrate for supporting FeS/ZnO nanoarrays, and the nanoarrays were vertically and uniformly grown on the substrate via a wet-chemical route. Under ultrasonic and solar irradiation, FeS/ZnO nanoarrays have high sono-photocatalytic activity for degrading methylene blue in water. The photogenerated carriers can be separated by a piezoelectric field and a built-in electric field, resulting in a low recombination rate and high photocatalytic efficiency. The piezophototronic and photocatalytic effects were coupled together. The experimental/theoretical data indicate that this novel wastewater treatment can co-use mechanical and solar energy in nature, and so is a promising technology for environment improvement.