Synthesis of FeVO4 Nanoparticles and Sensing Performance for Ethanol Gas under Different Solution pH

FeVO4 nanoparticles are synthesized by the hydrothermal method. The effect of micromorphology under different pH conditions is investigated. Their microstructure, morphology, and chemical composition are analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and N-2 adsorption-desorption. The results showed that an increase in pH leads to agglomeration of the material. The effect of different pH conditions on the gas-sensitive performance of FeVO4 is subsequently investigated, and the best response performance of the FeVO4 sensor is achieved at a pH of 3. The consequences showed that the FeVO4 sensor has a response of 3.383 to 100 ppm ethanol gas, with the response and recovery time of 1 and 7 s. The response cycle test has proved that FeVO4 has good stability. Analyzed in conjunction with the characterization results, the oxygen vacancies on the surface of the nanoparticles not only improve the electronic conductivity but also provide active sites for the adsorption of gases, which helps to improve the sensitivity of the material to gases.