The Role of Zn Ions in the Structural, Surface, and Gas-Sensing Properties of SnO₂:Zn Nanocrystals Synthesized via a Microwave-Assisted Route

Author(s)

da Silva, Luis F. ; Lucchini, Mattia A. ; Catto, Ariadne C. ; Avansi Jr., Waldir ; Bernardini, Sandrine ; Aguir, Khalifa ; Niederberger, Markus ; Longo, Elson

• Document type: Journal article
• Source: SENSORS; v. 24, n. 1, p. 13-pg., 2024-01-01.

Abstract

Although semiconducting metal oxide (SMOx) nanoparticles (NPs) have attracted attention as sensing materials, the methodologies available to synthesize them with desirable properties are quite limited and/or often require relatively high energy consumption. Thus, we report herein the processing of Zn-doped SnO2 NPs via a microwave-assisted nonaqueous route at a relatively low temperature (160 degrees C) and with a short treatment time (20 min). In addition, the effects of adding Zn in the structural, electronic, and gas-sensing properties of SnO2 NPs were investigated. X-ray diffraction and high-resolution transmission electron microscopy analyses revealed the single-phase of rutile SnO2, with an average crystal size of 7 nm. X-ray absorption near edge spectroscopy measurements revealed the homogenous incorporation of Zn ions into the SnO2 network. Gas sensing tests showed that Zn-doped SnO2 NPs were highly sensitive to sub-ppm levels of NO2 gas at 150(degrees)C, with good recovery and stability even under ambient moisture. We observed an increase in the response of the Zn-doped sample of up to 100 times compared to the pristine one. This enhancement in the gas-sensing performance was linked to the Zn ions that provided more surface oxygen defects acting as active sites for the NO2 adsorption on the sensing material. (AU)

• FAPESP's process: 13/09573-3 - Synthesis and Characterization of the ZnO/SnO2 Heterostructures obtained by Hydrothermal Method: Gas Sensor Applications
• Grantee: Luís Fernando da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 22/02927-3 - Gas sensors based on n-type semiconductors operating at room temperature: investigation of their performance and mechanisms involved
• Grantee: Luís Fernando da Silva
• Support Opportunities: Research Grants - Initial Project
• FAPESP's process: 15/20124-1 - Nanostructured Semiconductor Oxides: Nonaqueous Synthesis and their Gas Sensing Properties
• Grantee: Luís Fernando da Silva
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor