NiO hollow nanospheres with different surface by a bubble-template approach and its gas sensing

In this work, we report on the use of bubbles as a template, can adopt a slight hydrothermal method and subsequent calcination synthesized NiO hollow sphere successfully, and then control the reaction time and temperature conditions to form two different NiO surface. It was found that the fluffy structure with pores and the flower-like structure with nanometer plate. The results show that NiO with hollow sphere has excellent performance in gas sensing test and its special surface has high specific surface area, which has good response sensitivity to 400 ppm C2H5OH. So, it is a promising sensing material for detection of C2H5OH. In addition, based on the experimental results, we also proposed that the evolution mechanism about NiO hollow spheres and the gas sensitive mechanism on the surface of microspheres.