Novel Al-doped CdIn2O4 nanofibers based gas sensor for enhanced low-concentration n-butanol sensing

Fast and effective detection of harmful gases is crucial criterion for the current development of gas sensors. In this paper, a novel n-butanol gas sensor using Al-doped CdIn2O4 nanofibers (ACO NFs) is synthesized by an electrospinning method. The different morphologies of the as-prepared ACO NFs are controlled by doping different Al contents. Systematic characterizations demonstrate that the doping of Al to CdIn2O4 NFs would enhance the reaction activities between the gas and sensing materials, such as generating large amounts of adsorbed oxygen and improving the specific surface area of sensing materials. The results show that the detection limit of all prepared sensors for n-butanol is sub-ppm, and less than 250 ppb. The optimal Al-doped CdIn2O4 (5.0% Al/Cd molar ratio) based gas sensor results in 3.32-fold enhancement in gas response to 200 ppm n-butanol at an operating temperature of 300 °C and exhibits excellent long-term stability compared with the pure CdIn2O4. Hence, ACO NFs can be regarded as a promising sensing material for low-concentration n-butanol gas detecting. Also, the mechanisms for improving the sensing performance of ACO NFs based gas sensor are proposed.