Nd-doped CdS nanospheres for rapid and selective detection of n-butanol

This paper reports the first hydrothermal synthesis of Nd-doped (1–4 mol%) CdS gas sensor materials. After gas sensitivity testing, it was found that sensors doped with 3 mol% performed best in detecting n-butanol gas at 275 °C: the response to 100 ppm n-butanol reached 127 (approximately 3.34 times that of pure CdS), Compared with common VOC gases in daily life, the sensor has good selectivity for n-butanol, with an extremely fast recovery time (3 s). It also demonstrated extremely high detection accuracy (R² = 0.96857) across a concentration range of 10–300 ppm n-butanol, along with excellent humidity resistance and long-term stability. Characterization of the material was conducted using XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope), and XPS (X-ray photoelectron spectroscopy), revealing the following reasons for the enhanced gas-sensing performance: 1. Nd³ ⁺ doping causes lattice distortion, forming a highly active region around the sulfur vacancy and enhancing the gas-vacancy electron exchange efficiency. 2. Lattice distortion inhibits grain growth (≈26.85 nm), providing more gas adsorption/reaction sites and significantly improving the response value. reaction sites, significantly improving the response value. 3. Nd³ ⁺ reduces the adsorption energy of n-butanol, promoting gas adsorption/reaction processes while accelerating desorption. This paper provides materials with practical application value for sensors used in n-butanol detection.