PANI-Based Hydrogen Sulfide Gas Sensors

Meenakshi Kumawat,Gopinath Halder,Pooja Shandilya,Raj Kumar Arya,George D Verros,Sanghamitra Barman,Devyani Thapliyal

doi:10.3390/coatings12020186

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.

Highlights

Chemical sensors, gas sensors, are produced in the form of thick and thin films to detect H2S gas in the environment as rapid, low-cost, and compact devices
The hydrogen sulfide gas-sensitive chemiresistive sensor using a nanocomposite of PANI/WO3/CuCl2 was screen printed on flexible plastic substrate of polyethylene terphthalate (PET)
The nano-scale morphology of the composite was confirmed by FE-SEM analysis which showed tungsten oxide particles in nano-rectangular shapes, i.e., rod-like structure

Summary

Introduction

Gas sensors, are produced in the form of thick and thin films to detect H2S gas in the environment as rapid, low-cost, and compact devices. They are evolving as significant environmental monitoring devices, delivering analytical data or signals of harmful gases. A gas sensor is a type of chemical analyzer that responds selectively and reversibly to the surrounding environment. It converts the concentration of a gas into a quantifiable signal.

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