Metal-organic framework-derived Cr-doped hollow In2O3 nanoboxes with excellent gas-sensing performance toward ammonia

Transition metal ions doping is an effective method to improve the gas sensing performance of metal oxide semiconductors. Herein, we report the synthesis of Cr-doped In2O3 samples by calcining metal-organic frameworks (MOFs)-precursors prepared by a simple oil bath method. The experimental characterization results show that the as-prepared samples exhibit uniform hollow nanoboxes with large specific surface areas. Through comparison, the 0.5 wt% Cr-doped In2O3 sample with complete and regular morphology was selected for a series of gas-sensitive performance tests. The results show that the sensor has good detection performance for ammonia (NH3). Gas-sensing tests revealed that the sensor exhibited excellent sensing performance towards NH3 with low operating temperature (140 degrees C), high selectivity, good repeatability, relatively high response, low detection concentration (similar to 1 ppm), and short response time (similar to 1 s). The generation of lattice defects and the increased conductivity after doping are the reasons for the excellent performance of the sensor. This provides a new strategy for the research and preparation of high perfor-mance gas sensors. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The Cr-doped In2O3 samples synthesized by calcining metal-organic frameworks (MOFs)-precursors exhibit uniform hollow nanoboxes with large specific surface areas, and the 0.5 wt% Cr-doped In2O3 sample shows excellent gas sensing performance for NH3. The sensor has low operating temperature, high selectivity, good repeatability, relatively high response, low detection concentration, and short response time.