Ultrasound assisted quick synthesis of square-brick-like porous CuO and optical properties

Square-brick-like CuC2O4 intermediate was synthesized quickly by an ultrasound and microwave assisted solution route in the presence of sodium dodecyl benzene sulfonate (SDBS) surfactant using CuCl2 and K2C2O4 as raw materials. The CuC2O4 was transformed into CuO with a preserved morphology by heating at 300 °C for 2 h. The products were characterized by XRD, TG-DTA, XPS, SEM, TEM, HRTEM and N2 adsorption–desorption measurement. The light harvesting capability, photoluminescence and surface photovoltage properties of the CuO were investigated. The width and thickness of the obtained porous CuO square bricks are ca. 0.5–1 μm and 200 nm, respectively. Its average primary particle size is 12 nm. The formation mechanism of this square-brick-like CuO was investigated on the basis of series of controlling experiments. The results show that SDBS, C2O42− and ultrasonic processing play important roles in the formation of this square-brick-like morphology.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ultrasound was used for preparation, which is fast and energy-saving. ► Morphology and microstructure of the square-brick-like CuO has been hardly seen. ► CuO square bricks possess hierarchical porous structure and emit purple-blue light. ► SDBS, C2O42− and ultrasound are key factors to formation of square-brick-like morphology. ► The synthesis route is simple, efficient and raw materials are cheap.