Abstract
Recently, perovskite-type oxides have been reported to have outstanding gas sensing performance. However, facile synthesis of uniform materials with controllable morphologies and low limit of detection are still great challenges. In this paper, the synthesis of Ln[Fe(CN)6] (Ln[dbnd]La, Nd, Sm) with novel morphologies was achieved by introducing polyvinyl pyrrolidone (PVP) in dilute water/alcohol solutions to induce and regulate crystal growth using a co-precipitation method at room temperature. Then, the oxygen-vacancy rich LnFeO3 materials were obtained by high-temperature annealing. Among them, LaFeO3-based sensor has a low detection limit of 1 ppm n-propanol with a gas-sensing response of 2.5 at a relatively low operating temperature of 120 °C. In addition, by analyzing the influence of Ln3+ on the morphology and crystal structure of LnFeO3, the reasons for the better gas-sensing performance of LaFeO3-based sensor compared with that of the sensors based on NdFeO3 and SmFeO3 are expounded. This simple method of preparing porous LnFeO3 can be extended to the preparation of other ABO3-type gas-sensing materials using in trace detection.
NSTL
Elsevier