PANI-Based Hydrogen Sulfide Gas Sensors

Abstract

A hydrogen sulfide gas-sensitive chemiresistive sensor was screen printed on a flexible polyethylene terphthalate substrate using a nanocomposite of polyaniline(PANI)/WO3/CuCl2 (PET). FE-SEM analysis validated the nanoscale morphology of the composite, which revealed tungsten oxide particles in nano-rectangular forms, i.e., rod-like structures. The gas-sensing capabilities of the film were affected by the PANI and WO3 ratio, with the optimal ratio of 0.5 showing the best response. It was tested at various H2S gas concentrations and demonstrated a progressive response as the gas concentration increased. PANI/WO3/CuCl2 film was more sensitive than PANI/CuCl2 binary composite film. Around 1 ppm of gas concentration, with a response time of 67.9 s at room temperature, the highest response of two orders of magnitude change was observed, of 93%. This study found that PANI/WO3/CuCl2 is an excellent composite for improving the reversibility and humidity sensitivity of PANI/CuCl2 composite-based chemiresistors during H2S gas sensing, and that screen printing is a simple and cost-effective method for producing stable and uniform film-based chemiresistive gas sensors.