High-performance ethylene glycol room temperature gas sensor based on directly carbonized equisetum for ultrasensitive and rapid detection

Ethylene glycol (C 2 H 6 O 2 ) is a widely used industrial chemical whose leakage poses significant environmental and health risks, necessitating the development of efficient detection technologies. Current chemiresistive ethylene glycol sensors mostly rely on metal oxides that have high operating temperatures, poor moisture resistance, and high costs. Here, to tackle this issue, we fabricated biomass-derived carbon materials via one-step pyrolysis using raw equisetum (RE) as the abundant natural precursor. The as-obtained carbonized equisetum (CE) retains the native tubular vascular structure of the raw plant and carries trace self-doped K and Cl originating from the pristine plant. By regulating the pyrolysis temperature, the CE-4 sensor (carbonized at 400 °C) exhibits excellent room-temperature sensing performance toward ethylene glycol. On this basis, this study focused on investigating the ethylene glycol sensing mechanism of the horsetail-based biocarbon material. It systematically clarified the intrinsic correlation between the material’s defect density, surface adsorbed oxygen concentration, and carrier transport properties under pyrolysis temperature regulation. It also elucidated the regulatory mechanism of these factors on the sensing performance.