Enhanced H2S gas detection using low-cost carbon-loaded CuCrO2–CuO nanomaterials

Abstract

Effective monitoring of H₂S gas is crucial, as inhaling H₂S poses a significant risk to human health, potentially leading to grave harm or even death. Chemiresistive semiconducting metal oxides (SMOs) play a crucial role in detecting low concentrations of H₂S, providing early cautioning and ensuring immediate action. To develop affordable chemiresistive gas sensors guaranteeing no trade-offs in sensitivity and selectivity, ongoing research continues to explore different SMOs, enhancing their performance. This study focuses on leveraging affordable carbon-based nanomaterials in CuCrO₂ to improve H₂S detection, highlighting the efficacy of candle soot (CS) as an effective carbon source for H₂S gas. The CS (1.5 wt%) loaded CuCrO₂ provides a large surface area, which results in a relative response of 66.4% and 31% toward 50 ppm and 100 ppb of H₂S gas, respectively, at 100 °C. The 1.5_CS@ CuCrO₂ gas sensor performs exceptionally well in a highly humid (RH 80%) atmosphere with a relative response of 65.9% for 50 ppm of H₂S gas, despite the hydrophilic nature of candle soot. The first principle density functional theory (DFT) calculations indicate that the hybrid carbon system can detect H₂S gas due to its high adsorption energy, charge transfer, and orbital interactions compared to the CuCrO₂ system.