An efficient chemical precipitation route to fabricate 3D flower-like CuO and 2D leaf-like CuO for degradation of methylene blue

A facile and eco-friendly way for fabrication of CuO is developed based on an one-step chemical precipitation route without calcination procedure or use of surfactant. The structure features of as-prepared CuO are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N2 adsorption-desorption experiment. X-ray diffraction analysis shows that CuO with particle size of 13.5–19.2 nm and crystallinity of 67.0–72.9% can be fabricated by the transformation of Cu(OH)2 precursor at bath temperature above 50 °C. By adjusting the oil bath temperature and the content of ammonium hydroxide, we demonstrate a formation mechanism to control CuO to be 2D leaf-like structure with large specific surface area of 33.4 m2/g and pore volume of 0.226 cm3/g, or 3D flower-like ones with specific surface area of 7.45–18.7 m2/g and pore volume of 0.0249–0.0850 cm3/g. The catalytic performances of as-prepared CuO are evaluated by monitoring degradation of methylene blue in the presence of hydrogen peroxide. Almost 100% methylene blue degradation rate can be reached after reaction for 210 min on 3D flower-like CuO synthesized with 10 mL ammonia content in oil bath of 50 °C. The high activity can be correlated with the morphology and pore volume of CuO. The present synthetic strategy is an inexpensive and convenient way suitable for large-scale fabrication of copper oxides, which are potential catalysts for organic compounds degradation.