Energy level regulation to optimize hydrogen sensing performance of porous bimetallic gallium-indium oxide with ultrathin pore walls

Although hydrogen sensors with high-response have been extensively studied and developed, it is still a great challenge to achieve ultra-fast response and recovery, high sensitivity and excellent selectivity towards hydrogen (H2) for a gas sensor. Herein, porous Ga-In bimetallic oxide with atomically thin pore wall was synthesized by electrospinning and followed calcination. The sensor based on this sensing material (Ga1.2In0.8O3) showed ultra-short response and recovery time (≈1 s and 3 s), high response (Ra/Rg≈15–500 ppm H2), good reproducibility, remarkable stability, low detection limit (2 ppm) and excellent selectivity (without cross-response to carbon monoxide). The enhanced hydrogen gas sensing performance of this material can be attributed to its novel atomically thin wall, optimal Fermi level and abundant chemisorbed oxygen.