ZnO hollow pitchfork: coupled photo-piezocatalytic mechanism for antibiotic and pesticide elimination

Abstract

Photo-piezocatalytic degradation of organic dye (rhodamine B), pesticide (malathion), and antibiotic (ibuprofen) in an aqueous solution was performed by using a zinc oxide (ZnO) hollow pitchfork, which was synthesized by a hydrothermal technique. It can efficiently employ visible light and vibrational energy for the photo-piezocatalytic breakdown of contaminants. A ZnO hollow pitchfork showed a rhodamine B dye decomposition ratio of 85% within 80 minutes under a photo-piezotronic effect, which is significantly greater than the decomposition ratios of 35% and 55% for photocatalysis and piezocatalysis, respectively. The piezo potential generated in the ZnO pitchfork under strain was measured to be 84.72 V. This strain-driven polarized electric field promotes the separation of a photogenerated electron (e⁻)–hole (h⁺) pair, which results in improved photocatalytic activity. This current study demonstrates an application in improving the catalytic performance of pollutant decomposition by capturing light and vibrational energy from natural surroundings.