Effect of transformation temperature toward optical properties of derived CuO/ZnO composite from Cu–Zn hydroxide nitrate for photocatalytic ciprofloxacin degradation

Abstract

In this work, visible light driven CuO/ZnO photocatalyst composite derived from Cu–Zn hydroxide nitrate (CuZn–HN) was fabricated via thermal transformation at varying temperatures. The effect of temperature on their morphology and optical properties was examined. The CuZn–HN calcined at 400 °C (400HN) showed the better performance than 200HN, 800HN and uncalcined CuZn–HN in terms of the photocatalytic oxidation rate for Ciprofloxacin (CIP) degradation under visible light irradiation conditions. The improved photocatalytic performance of 400HN could resulted from the combination of narrow energy band gap, suppressed photogenerated e−-h+ recombination, and strong interactions between CIP and the composite' surface. The finding suggested the transformation temperature of CuZn–HN to CuO/ZnO composite is a key factor to produce the highly effective photocatalyst with the simple protocol as an alternative synthetic method to prepare the mixed metal oxide composites. Moreover, the photocatalytic CIP degradation pathway was elucidated by GC-MS analysis, and the charge transfer mechanism in CuO/ZnO composite was also proposed.