Initiation of piezoelectricity expands the photocatalytic H2 production and decomposition of organic dye through g-C3N4/Ag/ZnO tri-components

Abstract

The enhancement of photocatalytic reactivity through the internal electric field has received much attention. The combination of the piezoelectric effect and the photo-exiting process facilitates the segregation of the photogenerated carriers, thereby boosting the piezo-photocatalytic activity. We have constructed g-C3N4/Ag/ZnO tri-component composites; with various g-C3N4 precursors to achieve reliable photo/piezo-photocatalysis for H2 production and Rhodamine B (RhB) dye degradation. We observed that urea-based g-C3N4/Ag/ZnO (UCAZ) tri-components exhibit a superior H2 production rate of 1125.5 μmol h−1 g−1 under photocatalytic conditions. When piezoelectric-potential was introduced into the photocatalysis reaction via ultrasonic, the H2 rate increased dramatically to 1637.5 μmol h−1 g−1, which is approximately 145% greater than that light irradiation alone.Similarly, the catalytic decomposition ratio of Rhodamine B (RhB) under the coexistence of ultrasound and light, and degradation efficiency reached 99% in 120 min, which is higher than the value of (42%, 0.0031 min−1) for piezo-catalysis and (80%, 0.01 min−1) for photocatalysis condition alone. The rate constant under synergisticsimulation reaches 0.021 min−1, which is 200% and 645% times higher than the sole light and ultrasonic illumination. Additionally, RhB degradation of all the tri-components was performed under solar light (Sunlight) and ultrasound irradiation, and efficiency reached 99.5% in 45 min with a rate constant of 0.06 min−1, which is 300% higher than the piezo-photocatalytic under LED source. The enhanced performance of the g-C3N4/Ag/ZnO tricomponent is attributed to the high specific surface area (168 m2 g−1) and synergetic effect of piezo catalysis and photocatalysis.