Synthesis and characterisation of cerium sulphide over optical fiber and its gas sensing application

Abstract In this study, a cladding‐modified optical fiber‐based gas sensor is proposed for detection of carbon dioxide gas. Cerium disulphide (CeS 2 ) is synthesised and coated by chemical bath deposition (CBD) route over the region in which cladding is removed. This synthesised cerium disulphide is characterised by x‐ray diffraction (XRD), photoluminescence spectrum (PL), ultra violet‐visible absorption spectrum, ultra violet ‐visible reflectance and transmittance spectrum, scanning electron microscope images (SEM) and energy dispersive x‐ray spectrum (EDX). The response of the sensor is recorded for different concentrations of test gases (nitrogen dioxide and carbon dioxide) and the sensor's selectivity is compared and analysed. It is observed that cerium disulphide is more sensitive to carbon dioxide compared t o nitrogen dioxide.