LAUSR

Abstract In this work, we have reported the tuning of defects by simple thermal annealing of as-synthesized ethylene glycol capped ZnO nanorods at 200–600 °C temperatures. X-ray diffraction (XRD) data has confirmed the formation of Wurtzite structure of ZnO and the presence of a small amount of tensile strain is confirmed by Williamson – Hall analyses of XRD data. The lattice strain is found to increase with increasing temperature up-to 400 °C and on further increase in temperature it is decreased. To study the influence of defects on photo-catalytic properties of the samples, the degradation of a test dye, namely Methylene Blue (MB) under UV–vis light irradiation has been carried out and the reaction kinetics has been determined by Langmuir-Hinshelwood model. It has been found that 400 °C annealed sample exhibits the highest photo-catalytic dye degradation efficiency of ∼83%, within only 20 min. The effect of initial MB dye loading on photo-catalytic efficiency of 400 °C annealed sample has also been tested and reported an optimum value of dye concentration. The successful introduction of defect states in 400 °C annealed sample, as confirmed by PL measurement, has played an important role to achieve the high photo-catalytic activity in the samples.