Influence of in-plane and bridging oxygen vacancies of SnO2 nanostructures on CH4 sensing at low operating temperatures

Abstract

Role of 'O' defects in sensing pollutant with nanostructured SnO 2 is not well understood, especially at low temperatures. SnO 2 nanoparticles were grown by soft chemistry route followed by subsequent annealing treatment under specific conditions. Nanowires were grown by chemical vapor deposition technique. A systematic photoluminescence (PL) investigation of 'O' defects in SnO 2 nanostructures revealed a strong correlation between shallow donors created by the in-plane and the bridging 'O' vacancies and gas sensing at low temperatures. These SnO 2 nanostructures detected methane (CH 4 ), a reducing and green house gas at a low temperature of 50 °C.Response of CH 4 was found to be strongly dependent on surface defect in comparison to surface to volume ratio. Control over 'O' vacancies during the synthesis of SnO 2 nanomaterials, as supported by X-ray photoelectron spectroscopy and subsequent elucidation for low temperature sensing are demonstrated.

Invoking forbidden modes in SnO2 nanoparticles using tip enhanced Raman spectroscopy

“…SnO 2 NPs were synthesized by annealing pristine quantum dots of size 2.4 nm at 300 and 800 °C in horizontal quartz tube furnace in the presence of air atmosphere for 1 h. The pristine sample was synthesized by soft chemical method, and a detailed synthesis and characterization of these NPs was reported elsewhere . Morphological studies of the synthesized materials were performed by high resolution transmission electron microscopy (HRTEM; Zeiss Libra 200) and field emission scanning electron microscopy (FESEM; Zeiss SUPRA 55) for samples annealed at different temperatures.…”

“…SnO 2 is an n ‐type wide band gap semiconductor with direct band gap of 3.6 eV. It is widely used as gas sensor, transparent conductors (when doped suitably), solar cells, Li‐ion batteries and also as a catalyst . The surface chemistry of a SnO 2 structures is a crucial parameter in all these applications .…”

“…It is widely used as gas sensor, transparent conductors (when doped suitably), solar cells, Li‐ion batteries and also as a catalyst . The surface chemistry of a SnO 2 structures is a crucial parameter in all these applications . High surface to volume ratio in nanostructured SnO 2 extensively manipulates its physiochemical properties, and its applications .…”

Electrochemical supercapacitor performance of SnO2 quantum dots

“…However for an effective use of QDs, it is very important to understand their distinct physical and chemical properties with respect to their bulk counterparts. Wide band gap n-type semiconducting SnO 2 nanostructures are well established for the use in technologically important applications like gas sensing, transparent electrodes, and as a catalyst [1][2][3][4]. It is also found that the SnO 2 is a potential material for much needed applications like solar cells [1,5,6], as anode materials in Li-ion battery [1,[7][8][9], and electrochemical supercapacitors [11][12][13].…”

Oxygen Vacancies Enhance Triethylamine Sensing Properties of SnO2 Nanoparticles

“…Bonu et al. found the in‐plane OVs in SnO 2 played an important role in methane detection in the light of the photoluminescence measurements results . To the best of our knowledge, SnO 2 nanocrystals with abundant OVs are generally used to enhance the sensing performances of NO 2 and CH 4 , but the detection of TEA in this type gas sensor are rarely reported.…”