One-step room-temperature solid-phase synthesis of ZnFe_2O_4 nanomaterials and its excellent gas-sensing property

摘要

ZnFe_2O_4 nanomaterials have been synthesized by simple one-step solid-phase chemical reaction between Zn(CH_3COO)_2 ? 2H_2O, FeCl_3 ? 9H_2O and NaOH within a very short time at room temperature. The solid-phase products were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, thcrmogravimetic analysis, transmission electron microscopy and scanning electron microscopy. Results indicated that the particle size of product can be obviously let up and the agglomeration phenomenon can be improved by the surfactant. Moreover, the ZnFe_2O_4 nanomaterials were applied in gas sensor and exhibited much better sensing performance than bulk ZnFe_2O_4. The as-prepared ZnFe_2O_4 nanomaterials have high sensitivity, good selectivity and fast response/ recovery characteristic for ethanol and hydrogen sulfide. The improved ZnFe_2O_4 nanomaterials have high response value of 21.5 and 14.8 for ethanol and hydrogen sulfide in the optimized operating temperature of 332 °C and 240 °C, respectively. The response and recovery time was found to be within 4 s and 14 s for ethanol, while 7 s and 25 s for hydrogen sulfide.