Rapid synthesis of ZnO nanowires and nanoplates with highly enhanced photocatalytic performance

Abstract

ZnO nanowires and nanoplates with extremely enhanced photocatalytic performance were prepared via one-step facile thermal decomposition of zinc acetate dihydrate and well characterized by FESEM, TEM, STEM-HAADF, EDX, XRD, PL, XPS, UV–Vis and Raman spectroscopy. FESEM and TEM studies revealed ZnO nanowires, nanoplates and few nanorods in the sample prepared at 300 °C, while increase in the thermal decomposition temperature to 500 °C led to the formation of ZnO nanoparticles and nanorods. XRD results revealed hexagonal wurtzite ZnO nanostructures with crystallite size variation from 47 to 34 nm with increase in thermal decomposition temperature, while PL studies showed decrease in band gap from 3.31 to 3.26 eV along with significant quenching of defect emissions as the thermal decomposition temperature was increased from 300 to 500 °C. ZnO nanowires and nanoplates prepared at 300 °C exhibited extremely enhanced photocatalytic performance and led to almost complete decomposition of methylene blue (MB) and methyl orange (MO) in only 6 and 32 min, respectively. The extremely strong photocatalytic performance of ZnO nanowires and nanoplates makes them exciting candidates for solar-driven water purification. The possible mechanisms of growth of ZnO nanowires and nanoplates and their enhanced photocatalytic performance were proposed.