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 synergistic simulation 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.