Synthesis and photocatalytic activity of novel CuO cauliflowers grown from Cu(OH)2

•Uniform CuO cauliflowers can be prepared by a simple hydrothermal method.•Methenamine plays a vital role in the formation of CuO cauliflowers.•CuO cauliflowers show superior photocatalytic activity.•Its high activity has been mainly ascribed to the high crystallinity.

Uniform and well-defined CuO cauliflowers have been prepared via a simple hydrothermal route, which form through the “oriented attachment (OA)–preferential growth–Ostwald ripening (OR)” processes. Furthermore, the CuO cauliflowers show a much higher activity than the irregular CuO for the degradation of rhodamine B (RhB). Its apparent rate constant (0.0156 min− 1) is 5.24 times higher than that (0.0025 min− 1) of the latter. The higher activity is mainly attributed to its higher crystallinity (84.02% vs. 62.86%), which can reduce the recombination rate of photogenerated electrons and holes.

Graphical abstractCuO cauliflowers show a higher degradation activity of RhB than the irregular one, which has been mainly attributed to its higher crystallinity.Figure optionsDownload full-size imageDownload as PowerPoint slide