Preparation of homogeneous porous Zn-CoOx and its response to alcohols under relative low operating temperature

A homogeneous porous Co 3 O 4 -ZnO nanomaterial (Zn-CoO x ) was successfully fabricated by precipitation-annealing route. The as-prepared Zn-CoO x exhibited good response, reliable reversibility and good selectivity towards alcohols, which attributed to the porous structure and p-n heterojunction formed between Co 3 O 4 and ZnO. In particular, the different Fermi levels of Co 3 O 4 and ZnO leaded to a further increase the depth of the space charge layer, which improved the gas sensitivity of the material from 10% to 480%. Besides, the continuous Co 3 O 4 leaded to a relatively lower operating temperature and resistance. This material preparation method and bimetallic oxides could be widely used in the research and development of metal oxide gas sensitive materials and sensors.