Room temperature chlorine gas sensor based on alpha-titanium phosphate synthesized from ilmenite beach sand

Abstract

The demand for chlorine gas detection techniques is increasing due to their toxicity and widespread use in various applications. This study successfully developed a novel chlorine gas sensor based on alpha-titanium phosphate synthesized from ilmenite as a value addition to the ilmenite beach sand in Pulmoddai, Sri Lanka. Natural graphite and carboxymethyl cellulose were also incorporated as minor components of the sensor material. Characterization via X-ray diffraction, Fourier transform infrared spectroscopy, and Raman spectroscopy confirmed alpha-titanium phosphate synthesis and sensor composition. The electrical measurements of the sensor via a four-probe conductivity meter revealed ohmic behavior with 0.31 S/m conductivity. The sensor, operating at room temperature, can detect chlorine gas concentrations as low as 20 ppm. It exhibits a sensitivity of 0.185 mV/ppm, a response time of 2-3 minutes, and a recovery time of 1-3 minutes, demonstrating excellent selectivity towards chlorine gas and stability over time.