Ni infused ZnO flake-like nanostructure for enhanced gas sensing performance

• Published in: Journal of molecular structure 2025-02, Vol.1322, p.140389, Article 140389
• Main Authors: Lokhande, S.D., Awale, M.B., Kathwate, L.H., Zadke, V.B., Mote, V.D.
• Format: Article
• Language: English
• Subjects: Acetone sensing; Chemical synthesis; Nanoflake; Stress; Urbach energy
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2024.140389

•The Ni doped ZnO nanoflakes were successfully synthesized through a spray pyrolysis method.•3 % Ni-doped ZnO showed 86 % acetone sensing at 50 ppm, room temperature.•Smaller nanoflakes in 3 % Ni-doped ZnO enhanced surface area for sensing.•Ni doping increased Urbach energy, indicating more electronic disorder.•Higher Ni doping improved response time but decreased overall sensing. The proposed paper features undoped and Ni doped ZnO films for the acetone sensing capability optimized for room temperature operations. ZnO thin films with Ni doping were fabricated by a spray pyrolysis technique. X-ray diffraction (XRD) study indicates that undoped and Ni doped ZnO films have polycrystalline nature of hexagonal (wurtzite) structure. The optical analysis showed that film transmittance values decrease with the intensification of nickel into the ZnO host lattice. The energy band gap of the films decreased from 3.24 to 3.17 eV with doping. This consequently showed an increase in Urbach energy values. Nanoflake morphology is observed for doped ZnO thin films. Nevertheless, slight changes in the nature of nanoflakes were observed with Ni doping. The composition of the elements was confirmed using Energy dispersive X-ray analysis (EDX). All the thin film samples were tested for gas sensing capability for acetone for low concentration (50 ppm). Ni doped ZnO films at low doping percentage showed enhancement in sensing response of 86 % with lesser response time and recovery time of 30 s and 88s. However, at a higher doping percentage the response to acetone was observed to be reduced with a further decrease in response time. This study highlights that nanoflake morphology is consistent across all samples. However, the optimal gas sensing performance is achieved at lower Ni doping levels, with further doping leading to diminished response. Future development of Ni-doped ZnO-based sensors can offer high sensitivity even at room temperature. [Display omitted]