Influence of morphology and heterostructure formation on the NO2 gas sensing properties of the ZnO-NiO system

Author(s)

Tagliaferro, Julia Coelho ; Komorizono, Amanda Akemy ; Pessoa, Natalia Candiani Simoes ; Correia, Rayssa Silva ; Bernardi, Maria Ines Basso ; Mastelaro, Valmor Roberto

• Document type: Journal article
• Source: TALANTA OPEN; v. 10, p. 11-pg., 2024-12-04.

Abstract

The detection of toxic gases has gained significant attention in recent decades. Among various gas-sensing materials, metal oxide semiconductors (MOS) have emerged as highly promising due to their exceptional physical and chemical properties. However, a major limitation of MOS-based gas sensors is their lack of specificity, as they often respond to multiple gases, complicating the identification of target gases in mixed environments. This challenge can be addressed by combining two or more MOS materials to form a heterojunction, which modifies the electronic structure and enhances selectivity. NiO, a p-type semiconductor, has demonstrated the ability to improve both selectivity and sensor response when combined with ZnO, an n-type semiconductor. In this study, ZnO particles were synthesized via a precipitation method to produce two distinct morphologies: needle- and donut-like. These ZnO particles were subsequently combined with NiO via a hydrothermal reaction to form an n-p heterojunction. The selectivity of the resulting sensors was evaluated against O3, NO2, NH3, and CO gases. The results indicated that ZnO sensors with needle- and donut-like morphologies exhibited high responses to oxidizing gases but lacked adequate selectivity between them. In contrast, the ZnO/NiO donut-like heterostructure demonstrated high selectivity for NO2 detection. (AU)

• FAPESP's process: 22/07880-5 - Assessment of the gas sensing properties of ZnO nanoparticles with different morphologies for the detection of O3
• Grantee: Natalia Candiani Simões Pessoa
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass
• Grantee: Edgar Dutra Zanotto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/22076-5 - Reduced graphene (rGO) and metal semiconductor oxides (MOS) nanocomposites for application as toxic gas sensors
• Grantee: Valmor Roberto Mastelaro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/03325-7 - Development of flexible gas sensors based on rGO and rGO/ZnO conductive inks for detection of NO2 and NH3
• Grantee: Amanda Akemy Komorizono
• Support Opportunities: Scholarships in Brazil - Doctorate
• 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: 22/06404-5 - Assessment of the gas sensing properties of rGO-ZnO with different morphologies for the detection of O3
• Grantee: Rayssa Silva Correia
• Support Opportunities: Scholarships in Brazil - Scientific Initiation