Preparation and gas-sensitive properties of litchi shell-like NiO film modified porous ZnO composite by electrodeposition method

ABSTRACT A kind of litchi shell-like porous NiO/ZnO composite was prepared by the combination of chemical-deposition and then electrodeposition method. Firstly, the porous ZnO matrix material was prepared by soft template method, and then the continuous Ni layer was deposited on the surfaces of ZnO matrix by chemical deposition method to improve the conductivity of the matrix. The Ni layer on the surfaces of ZnO matrix was thickened by electrodeposition method, and the NiO films were finally formed on the surfaces of ZnO matrix after calcination. The morphology of the material showed the litchi shell-like with loose porous structure on the surfaces of the particles. The effect of electrodeposition time on gas sensitivity was investigated at room temperature. When the electrodeposition time was 45 min, the gas sensitivity of the composite material was the best, the respond to 100 ppm NOx gas was 74.0%, the response time was only 21 s, and the detection limit was 1 ppm at room temperature. The loose porous and n-p heterojunction structure of the composite improved the gas-sensitive performance of the material.