Sensitivity Enhancement of Printed In2O3 Sensors for H2S Gas Detection At Room Temperature

Flexible hydrogen sulfide (H2S) sensors were fabricated by printing hybrid nanocomposite manufactured from the combination indium oxide nanoparticles (In2O3 NPs), copper acetate monohydrate powder (CuAc), graphite flakes (Gt), and polystyrene (PS). A sensitive sensor to ~100 ppb of H2S gas at room temperature was printed from a nanocomposite composed of In2O3 NPs, Gt, and PS. Enhanced sensitivity to H2S gas detection was achieved at concentrations lower than 100 ppb (<; 100 ppb) with the nanocomposite's modification with CuAc powder. The enhanced sensing performance can be ascribed to copper sulfide (CuS) formation upon the exposure of CuAc to H2S gas molecules. CuS is a highly conductive material that enhances conductivity between neighboring materials and H2S reactions on the sensor's surface. Thus, a reduction in the electrical resistance was recorded upon the sensor's exposure to H2S gas, denoting an enhancement of the sensitivity.