A facile route to batch synthesis CuO hollow microspheres with excellent gas sensing properties

CuO hollow microspheres had been batch synthesized by a facile route of precipitating and annealing at 270 °C, which was derived from CuSO4·5H2O, Na2CO3 and CTAB. The morphology and structure of synthesized CuO powder were characterized by XRD, SEM, UV–Vis and BET. The formation mechanism of CuO hollow microspheres had been proposed based on the characterized structure and morphology. Firstly, the tiny Cu2(OH)2CO3 crystal strips are formed from CuSO4 and Na2CO3 aqueous solutions. Secondly, the tiny Cu2(OH)2CO3 crystal strips are assembled perpendicularly to the spherical CTA+ micelles surface due to the template of CTAB. Finally, the CuO hollow microspheres have been obtained due to the decomposition of Cu2(OH)2CO3 and burning of CTAB after annealing at 270 °C. High gas sensitivity to ethanol was achieved for the CuO hollow microspheres. The response of CuO hollow microspheres sensor is 5.6 to ethanol with the concentration of 400 ppm at 250 °C, and the responses/recover time is 17.0/11.9 s. Therefore, it indicates that the facile and batch route is a promising method to synthesize CuO hollow microspheres with excellent gas sensing properties.