Enhanced H₂S gas sensing of Pd functionalized NiO thin films deposited by the magnetron sputtering process

This letter presents the H2S gas sensing results of Pd-decorated NiO (Pd/NiO) thin films deposited by the magnetron sputtering process. The presence of the Pd catalyst enhanced the H2S sensing capability of NiO thin films in terms of high response (R-g/R-a ratio similar to 15) and relatively lower optimum operating temperature (T-opt) at 250 degrees C for 100 ppm H2S gas concentration. Further, the Pd/NiO thin films also exhibited a fast response/recovery time of similar to 65 s/29 s, low detection concentration (similar to 2 ppm), good stability, and high selectivity at T-opt (i.e., at 250 degrees C) towards H2S gas. The significantly improved H2S gas sensing properties of the Pd/NiO thin films can be mainly attributed to the modulation of the potential barrier and an increase in the specific surface area for the target gas adsorptions. Thus, the current work offers the development of highly responsive Pd functionalized NiO thin films for H2S gas sensors, which ensures low power requirements.