Photo-activated Pd-loaded WO3 for Enhanced H2S Sensing

Abstract

In this paper, pristine WO3 and Pd-loaded WO3 are synthesized via facile hydrothermal method and integrated with IoT-enabled portable resistance readout circuit for real time sensing performance measurement of the fabricated sensor towards H2S. A series of characterizations are performed to investigate the crystal structure, surface morphology, active surface area and elemental composition of the synthesized materials. Pristine WO3 nanoplates shows 9.13 sensing response towards 100 ppm H2S exposure while loading of 0.25 and 0.5 mol% Pd further improve the response up to 14.37 and 23.45 respectively. However, further loading of Pd (1 mol%) on WO3 nanoplates reduces the sensing response to 15.29. The fabricated 0.5 mol% Pd-loaded WO3 sensor is investigated under thermal and photo energy excitations. Moreover, temperature optimization of 0.5 mol% Pd-loaded WO3 exhibits higher sensing response 47.8 at 100 &#x00B0

C. Furthermore, under visible and ultraviolet illumination, the 0.5 mol% Pd-loaded WO3 sensor response increases from 47.8 to 57.3 and 63. The fabricated 0.5 mol% Pd- loaded WO3 sensor exhibits remarkable response, shorter response-recovery time, and ultra-selectivity towards analyte gas. IEEE