Copper-Based Pairs Modulation for High-Sensitivity H2S Detection in In2O3 NPs Sensor

This study investigated the performance of indium oxide nanoparticles (In
2
O
3
NPs)-based sensors modified with various copper salts for hydrogen sulfide (H
2
S) gas detection. Our approach involves substituting the conventional copper acetate monohydrate (h-Cu(CH
3
COO)
2
, h-CuAc) used in our prior research with alternative copper salts (Cu-salts). The sensors exhibited variable sensitivity to H
2
S concentrations ranging from below 100 ppb (< 100 ppb) to 1 ppm, depending on the copper salt’s type (monoatomic vs. polyatomic) and dissociation behavior (single and double dissociation). Our findings underscore the significance of conjugated base strength in influencing sensor sensitivity and response to H
2
S gas. The findings suggest that the sensor response is influenced by a combination of physical and chemical mechanisms, including chemisorption and base-acid reactions. Further investigation is needed to refine the understanding of the sensing mechanism.