Enhanced NO₂‐Sensing Properties of Cu‐Loaded SnO₂ Nanoparticles Synthesized via Precipitation and Impregnation Methods

Abstract

Herein, NO2 noxious gas sensors based on precipitation/impregnation synthesized SnO2 nanoparticles loaded with Cu2O (Cu2O–SnO2) are presented. The particle properties are characterized by nitrogen adsorption, X‐ray spectroscopic, and microscopic analyses. The NO2‐sensing performances in terms of sensor response, response times, selectivity, and stability are optimized by varying Cu contents. The optimal sensing film (1.0 wt%Cu–SnO2) shows a high sensor response of ≈5680–5 ppm of NO2 at a low operating temperature of 200 °C. In addition, 1.0 wt%Cu–SnO2 sensor exhibits very high NO2 selectivity against SO2, H2S, C2H5OH, H2, C2H2, C2H4, and CH4 compared with unloaded one. Therefore, the 1.0 wt%Cu–SnO2 sensor is a promising candidate for highly sensitive and selective detection of NO2.

Size-Dependent Response of Hydrothermally Grown SnO2 for a High-Performance NO2 Sensor and the Impact of Oxygen

“…32 On the other hand, the first principle study by Kılıçet al found that it was energetically favorable for Sn interstitials to be formed mutually alongside O vacancies. 32,33 Therefore, it is deduced that the energy band inside the gap is caused by rehybridized Sn 5s−5p of Sn interstitials formed along with the O vacancies. The clear relative O deficiencies observed in the bulk compared to the surfaces again imply surface depletion.…”