Exploring the potential of Bi2S3 nanoribbons in low temperature NO2 sensing: Experimental and theoretical insights by DFT studies

In this study, one-dimensional (1D) bismuth sulfide nanoribbons (Bi2S3 NRBs) were synthesized using a simple hydrothermal method and evaluated for room temperature gas sensing applications. Comprehensive characterization of 1D Bi2S3 NRBs confirmed their high crystallinity, orthorhombic structure, and unique morphology, consisting of horizontally aligned, strip-like structures that resemble NRBs with lengths exceeding 10 µm, and a specific surface area of ∼51 m2/g. These structural features make Bi2S3 NRBs highly suitable for gas sensing, offering enhanced surface interactions. When utilized as gas sensing materials, the Bi2S3 NRBs demonstrated selectivity for nitrogen dioxide (NO2) at room temperature, with a detection range from 500 ppb to 100 ppm. The sensor achieved a maximum response of 4.50 to 100 ppm NO2 and a detection limit as low as 500 ppb. Density functional theory (DFT) calculations supported these experimental results, revealing that NO2 molecules have a favorable adsorption energy on the Bi2S3 surface compared to other gases. The sensing interaction was primarily governed by charge transfer during physisorption. Overall, these findings highlight the potential of Bi2S3 NRBs as an effective room temperature NO2 gas sensing materials, offering good selectivity, and low detection limits, supported by favorable surface interactions elucidated through DFT analysis.