Ultra-sensitive methanol detection based on S-vacancy-enriched SnS: A combined theoretical and experimental investigation.

Theoretical calculations have confirmed that modulation of vacancy defects could enhance the sensing properties of semiconductor gas sensors effectively. In this work, we develop a novel and cost-effective process to prepare S-vacancy-enriched SnS (V s -SnS) for room temperature methanol sensors and further clarify the enhanced sensing mechanism of V s -SnS based on first-principles calculation. The V s -SnS were successful formed via one-step solvothermal process in Sn-rich environment, which could be confirmed by the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) techniques. Comparative investigations for methanol-sensing properties indicate that the V s -SnS display an ∼143.9-fold enhancement in gas response at room temperature compared with conventional-SnS (C–SnS). Meanwhile, ultrafast response/recovery and low detection limit are observed for the V s -SnS sensor (3 s of response time and 7 s of recovery time for 500 ppb methanol). The significant methanol sensing improvement could ascribed to the decrease in effective hole carrier concentration after introducing the S-vacancy as electron donor. The present study demonstrates the considerable effect and potential of vacancy modulation in the field of gas sensor applications, and the V s -SnS is promising in highly sensitive methanol sensors with low consumption. • A valuable strategy guiding the design of gas sensors based on 2D monochalcogenide. • Combination of first-principles calculations and experiment. • First synthesis of S-vacancy-enriched SnS. • Highly sensitive detection of methanol gas at room temperature. • Reveal the inner connection between theoretical calculation and experiment. [ABSTRACT FROM AUTHOR]