Research on lanthanum-doped fusiform hematite (α-Fe2O3) porous nanosheets for n-butanol gas sensor

Lanthanum (La) was incorporated into modify α-Fe 2 O 3 porous nanosheets via the smoldering solvothermal combustion method, and applied to establishing a gas sensor with high responsivity and rapid recovery. Material characterization revealed successful synthesis of the α-Fe 2 O 3 porous nanosheets with uniform incorporation of La. The introduction of La modulated both the morphology and pore size of the α-Fe 2 O 3 nanosheets , while also enhancing the oxygen vacancy content and specific surface area . Gas sensitivity testing demonstrated that the modified α-Fe 2 O 3 porous nanosheets exhibited superior gas-sensitized properties. Specifically, the Fe 2 O 3 /La-5 % exhibited a response of 81.55–100 ppm n-butanol at 275 °C, which was 8.43 times higher than that of pure α-Fe 2 O 3 (response value of 9.67), as well as excellent selectivity, fast response and recovery. Further analysis using UV-Vis spectrophotometry and electrochemical testing elucidated the mechanism underlying the enhanced gas-sensing performance, indicating that La doping influenced the microstructure and oxygen vacancy concentration of Fe 2 O 3 . The green, straightforward, and cost-effective synthesis method , coupled with the excellent gas-sensing performance, provides a theoretical basis for the advancement of high-performance n-butanol sensors. • La-doped Fe 2 O 3 porous nanosheets was prepared via the smoldering solvothermal combustion method. • The oxygen vacancy content and specific surface area of the α-Fe 2 O 3 nanosheets were adjusted by La doping. • Fe 2 O 3 /La-5 % exhibited superior gas-sensitized properties for n-butanol. • The mechanism of the enhanced gas-sensing performance was investigated by spectrophotometry and electrochemical testing.