Facile route to synthesize porous hierarchical Co 3 O 4 /CuO nanosheets with high porosity and excellent NO x sensing properties at room temperature

In this work, porous hierarchically structured Co3O4/CuO nanosheets were synthesized by a facile hydrothermal-calcination route. The CC2-1 sample synthesized with the 2:1 molar ratio of Co(NO3)2·6H2O and CuCl2·2H2O presented excellent NOx sensing performance at room temperature, which has not only the highest response (14.16–1000 ppm), the shortest response time (2 s to 1000 ppm), and the minimum detection limit (0.01 ppm), but also good reversibility and selectivity. It is could be associated with the unique hierarchical heterojunction structure which endowed with high porosity.