Improved H₂S sensing performances of facility-synthesized In₂O₃ nanocubes by doping with Mo

The pressing demand for environmental and health safeguarding has spurred intense enthusiasm among researchers to delve into metal oxide semiconductors (MOSs) based gas sensors. Particularly, the accurate detection of trace hydrogen sulfide (H₂S), which has drawn growing attention, has become a focal point. Herein, a molybdenum (Mo) doping strategy was presented to enhance the H₂S-sensitive properties of In₂O₃ nanomaterials to detect the presence of 1 ppm H₂S at comparatively lower temperatures. The Mo-doped In₂O₃ cubic nanoparticles (Mo-In₂O₃ CNPs) were synthesized through a hydrothermal route using In(OH) 3 as a precursor. When used as a sensitive material for the detection of H₂S, the Mo–In₂O₃ CNPs have shown some impressive improvements compared to pure In₂O₃ counterparts, including a reduction in working temperature (240 °C vs 300 °C), an increase in sensitivity (18.46 vs 11.34 for 20 ppm H₂S), a better selectivity (6.2 vs 2.84 times to ethanol), and a lower limit of detection (0.79 vs 0.47 ppm). Even to 1 ppm H₂S, the Mo-In₂O₃ sensor can give a response of 2.18, signifying its application feasibility in detecting trace amounts of H₂S. The multiple sensitization effects and their potential mechanism of Mo-In₂O₃ CNPs were discussed in detail.