Preparation of porous NiO/In2O3 nanoflower-like composites and their dual selectivity for CO/CH4

Abstract

In this paper, In2O3 nanoflowers decorated with different contents of NiO were synthesized through a simple two-step method, and then were used as an effective sensor for detecting CO/CH4. The flower-like structure is self-assembled from porous nanosheets with a size of about 2 μm and a thickness of about 14 nm. The gas-sensing test results showed that NiO/In2O3 exhibited the higher sensitivity toward CH4 and CO compared with pure In2O3. And NiO/In2O3 nanocomposites also showed excellent selectivity, good repeatability and stability. Furthermore, the sensor based on NiO/In2O3–2 (NiO/In2O3 nanoflower with the optimized C2H4NiO6 of 33 wt%) can achieve dual selective monitoring of CO and CH4 by controlling the operating temperature at 280 or 340 °C. In addition, it was also found that NiO/In2O3 can still achieve the detection of the target gas at 48% humidity. This study demonstrated the NiO/In2O3 nanocomposites possess a promising application in CO/CH4 dual selective detection.