IoT-enabled surface-active Pd-anchored metal oxide chemiresistor for H2S gas detection.

The Internet of Things (IoT) has a crucial role in advancing various fields such as Industry 4.0, Big Data, and Machine-to-Machine technologies. All systems continuously gather information on various parameters such as temperature, speed, pressure, health data, environmental conditions, and consumption. Considering this, we've developed a novel fabrication method for H 2 S gas sensor prototypes. These sensors are based on noble metal-functionalized on metal oxide semiconductor (MOS) chemiresistors. The fabrication process involved growing CuCrO 2 sensing thin film on SiO 2 /Si substrates using the RF sputtering method. Subsequently, Pd nanoparticles, known for their excellent gas-sensing catalyst properties, were functionalized onto the CuCrO 2 films using DC sputtering with varying sputtering times of 3, 6, 9, and 12 s. Nanorice morphology boosts gas absorption, capturing more target molecules. A 9 s Pd sputtering time greatly improved H 2 S sensing over other gases. CuCrO 2 film with Pd showed the highest 72.3% response to 50 ppm H 2 S, detecting down to 0.5 ppm. These results were achieved at the optimal working temperature of 150 °C. After optimizing parameters, we transferred the technology to develop a sensor module for the prototype with IoT integration. The prototype sensor connects to NODEMCU-ESP8266 Wi-Fi, which links to a smartphone through a mobile hotspot. [Display omitted] • Fabrication of Pd anchored CuCrO 2 nano rice morphology for highly toxic H 2 S gas sensors. • Pd NPs increase surface-to-volume ratio and improved the sensing performance due to spillover effect. • The measured sensing response was 72.3% at 150 °C for 50 ppm of H 2 S around with a lower detection limit of.5 ppm. • In Pd/CuCrO 2 better selectivity as compared to pristine CuCrO 2 and drastic improvement in sensitivity is observed. • Optimized sensor is interface with IoT platform for the real-life application. [ABSTRACT FROM AUTHOR]