Influence of annealing temperature on morphological and photocatalytic activity of sputter-coated CaCu3Ti4O12 thin film under ultraviolet light irradiation

Abstract

CaCu3Ti4O12 (CCTO) thin films were deposited by radio frequency (RF) magnetron sputtering and subsequently annealed at 300, 400, 500, or 600 °C. The XRD analysis showed that the amorphous CCTO thin film transformed to more crystallite structure as the annealing temperature increased to 600 °C. Generally, the average crystallite size, grain size and roughness of the thin films increased with increasing annealing temperature. Photocatalytic activities of these thin films were evaluated by the effectiveness of Rhodamine B (RhB–C28H31ClN2O3) removal from solution under ultraviolet (UV) light illumination. In particular, the CCTO thin film annealed at 600 °C exhibited the highest photocatalytic activity, where it removed 67.4% of RhB dye in 4 h, at a rate constant of 0.217 min−1. This observation was ascribed to its higher crystallinity and larger grain size of CCTO thin film annealed at 600 °C.