Enhancing n-Butanol Sensing of Entropy-Stable Perovskite Oxides by Synergistic Adsorption and Increased Gas Diffusion of Surfaces

High-entropy perovskite oxides have emerged as promising candidates for high-performance gas sensors due to their multicomponent, enhanced surface reactivity, and adjustable electronic structure. Herein, we synthesized a series of entropy-stabilized perovskite oxides, among which La0.25Pr0.25Sm0.25Nd0.25FeO3 exhibited exceptional n-butanol sensing performance, achieving both a high response value (95-20 ppm) and an ultralow detection limit (100 ppb). Furthermore, through in situ Fourier transform infrared (FT-IR) spectroscopy and density functional theory (DFT) calculations, we uncovered two critical factors driving the superior gas-sensing performance: synergistic adsorption and gas diffusion of surface enhancement. The severe lattice distortions inherent to entropy-stabilized systems promote synergistic adsorption at the Fe sites, significantly boosting sensitivity. Simultaneously, the increased gas diffusion rate accelerates the desorption of the absorbed gas and greatly reduces the recovery time. The synergistic interplay between synergistic adsorption and the gas diffusion rate increases highlights the unique advantages of entropy-stabilized perovskite oxides for gas sensors.