Piezo-photocatalytically enhanced H2 production and pollutant removal from ZnO nanorods grown on g-C3N4 layers

Abstract

Society needs sustainable catalytic materials for solar energy conversions and environmental remedial applications. g-C3N4/ZnO nanocomposites were produced via a facile technique with various precursors of g-C3N4. Structural, elemental, morphological, and optical studies were performed initially for the obtained nanocomposites. g-C3N4/ZnO nanocomposites exhibited the piezo-photocatalytic degradation of Rhodamine B (RhB) and H2 production. Urea-based composite, g-C3N4[U]/ZnO (CNU/Z), exhibited the highest performance on par with the composites obtained from the sources, melamine (M), Thiourea (T), and Dicyanamide (D). High surface area of 182.3 m2/g was measured for CNU/Z nanocomposite via the BET analysis. The production of H2 and dye degradation over CNU/Z composite provides the finest performance (827.5 μmol/g/h, 82%) under solar light and visible light. When ultrasound is additionally used along with the photocatalytic reaction course, the H2 production and dye degradation rate reaches up to 1497.5 μmol/g/h and 99%. The Piezo-photocatalytic reaction was dominated by superoxide radicals (.O2−) in the CNU/Z-assisted catalysis. The stability of the CNU/Z composite is shown through four piezo-photocatalytic cycles with a considerable consistency efficiency. The piezo-photocatalytically improved efficiency in CNU/Z is due to the synergistic effect of piezo-catalysis and photocatalysis.