A Combined Experimental and Theoretical Study of Composite Sno2-Bivo4 for Selective No2 Sensing

Abstract

Tin oxide-bismuth vanadate heterostructures (SnO 2 -BiVO 4 ) exhibit considerably enhanced surface-exposed edge sites with an abundance of the dangling bond due to their intrinsic crystallographic anisotropy. Its high chemical reactivity and chemisorption capabilities make it ideal for high-performance electrochemical sensing. In this paper, tin oxide-bismuth vanadate heterostructures (SnO 2 -BiVO 4 ) were synthesized via a facile hydrothermal synthesis method and employed as room temperature NO 2 sensor. The heterogeneous structure of as-synthesized SnO 2 -BiVO 4 has been examined via X-ray diffractometers (XRD), scanning electron microscopes (SEM), and transmission electron microscopes. (TEM), X-ray photoelectron spectrometer (XPS) and ultraviolet-visible spectrometer (UV-vis). The as-prepared SnO 2 -BiVO 4 (1:1) exhibited the optimal gas-sensing performance toward 0.1 ppm to 1 ppm NO 2 at relatively low optimal operating temperature (298 K) including fast response, fast recovery, high sensitivity and good reproducibility. The experimental data demonstrated that the as-synthesized SnO 2 -BiVO 4 has huge future potential for real-time detection of the trace of NO 2 at room temperature. Density Functional Theory (DFT) calculations were analyzed to reveal the underlying principles behind the experimentally observed improvement.

Keywords: Nitrogen dioxide, gas sensor, SnO2, BiVO4, DFT