Tailoring WSe2 nanosheets with Cu2O nanoparticles for high-performance room-temperature H2S sensing

The protection of human health and the world’s ecosystem necessitates the immediate development of low power, highly selective chemiresistive hydrogen sulfide (H 2 S) gas sensors. Herein, for the first time we report on the fabrication of cuprous oxide (Cu 2 O) nanoparticles decorated tungsten diselenide (WSe 2 ) nanosheets for selective detection of H 2 S gas. In the initial step, a continuous WSe 2 film was deposited on SiO 2 /Si substrate using a hydrogen free atmospheric pressure chemical vapor deposition (APCVD) method. Subsequently, the bottom-up grown WSe 2 film was functionalized through the deposition of Cu 2 O nanoparticles employing simple aerosol assisted chemical vapor deposition (AACVD) technique. Morphological, structural and compositional analyses of the sensing layer confirm the abundant distribution of Cu 2 O nanoparticles over WSe 2 surface. Within the experimentally tested range of 1 to 7 ppm, the sensor exhibited a remarkable response of 14% and 28%, respectively, without applying any external stimuli. Based on this experimental data, a theoretical limit of detection (LOD) as low as 380 ppb was calculated, along with a notable sensitivity of 2.25% ppm -1 towards H 2 S gas. Furthermore, the sensor demonstrated pronounced selectivity, outstanding repeatability, robust long-term stability and partial humidity tolerance. Overall, these results represent a major advancement for metal oxide functionalized transition metal dichalcogenides (TMDs) in the field of H 2 S gas sensing for environmental safety.