Scandium-doped CdS flower-like nanostructures gas sensor for high response and high selectivity 1,2-propanediol detection

1,2-Propanediol (1,2-PG) is a widely used industrial raw material, and excessive inhalation endangers human health, demanding efficient on-site detection. Conventional 1,2-PG gas sensors are constrained by poor selectivity, low response, and high operating temperatures. To address these limitations, this work employs Sc doping in CdS for 1,2-PG sensing and proposes a synergistic “lattice distortion-electronic-chemical-sensitization” strategy. Sc-doped flower-like CdS nanostructures were synthesized via a one-step hydrothermal method, with their physicochemical properties characterized by XRD, TEM, XPS, and BET. Results indicate uniform Sc incorporation into the CdS lattice without impurity phases, inducing lattice distortion, grain refinement, and optimized porosity. The 5 mol% Sc-doped CdS sensor exhibits superior performance at 180°C: an ultra-high response of 397.66–109 ppm 1,2-PG (13.26-fold that of pure CdS), a low detection limit of 144 ppb, excellent selectivity, rapid response-recovery, and good reproducibility. The enhanced sensing performance is attributed to Sc-induced synergistic structural modulation, electronic and chemical sensitization originating from lattice distortion and modified-surface properties. This work not only provides a facile strategy for fabricating high-performance 1,2-PG gas sensors but also contributes to the advancement of environmental monitoring technologies, offering reliable technical support for controlling 1,2-PG-related environmental pollution.