Design and Synthesis of Novel 2D Porous Zinc Oxide-Nickel Oxide Composite Nanosheets for Detecting Ethanol Vapor

Abstract

The porous zinc oxide-nickel oxide (ZnO-NiO) composite nanosheets were synthesized via sputtering deposition of NiO thin film on the porous ZnO nanosheet templates. Various NiO film coverage sizes on porous ZnO nanosheet templates were achieved by changing NiO sputtering duration in this study. The microstructures of the porous ZnO-NiO composite nanosheets were investigated herein. The rugged surface feature of the porous ZnO-NiO composite nanosheets were formed and thicker NiO coverage layer narrowed the pore size on the ZnO nanosheet template. The gas sensors based on the porous ZnO-NiO composite nanosheets displayed higher sensing responses to ethanol vapor in comparison with the pristine ZnO template at the given target gas concentrations. Furthermore, the porous ZnO-NiO composite nanosheets with the suitable NiO coverage content demonstrated superior gas-sensing performance towards 50–750 ppm ethanol vapor. The observed ethanol vapor-sensing performance might be attributed to suitable ZnO/NiO heterojunction numbers and unique porous nanosheet structure with a high specific surface area, providing abundant active sites on the surface and numerous gas diffusion channels for the ethanol vapor molecules. This study demonstrated that coating of NiO on the porous ZnO nanosheet template with a suitable coverage size via sputtering deposition is a promising route to fabricate porous ZnO-NiO composite nanosheets with a high ethanol vapor sensing ability.

NiO-Based Gas Sensors for Ethanol Detection: Recent Progress

“…Journal of Sensors could effectively improve their gas sensing properties [63]. Su et al [53] prepared a new and unique crescent-shaped NiO nanosheet.…”

“…In recent years, NiO has been reported to recombine with n-type semiconductors such as ZnO [63,[100][101][102][103][104][105][106][107][108][109][110], SnO 2 [67,[111][112][113][114][115][116][117][118], WO 3 [119][120][121], Fe 2 O 3 [122][123][124], and In 2 O 3 [125,126].…”

“…When the shell of the core-shell structure was thicker, the resistance modulation through the shell would be significantly reduced, owing to the depletion of some electron in the thick shell, thus resulting in a reduced gas response. Liang et al's team [63] sputter-deposited NiO onto porous ZnO nanosheets. NiO was uniformly attached to ZnO, and the addition of NiO narrowed the pore size on ZnO nanosheets (Figure 7).…”

Synthesis, Properties, and Selected Technical Applications of Magnesium Oxide Nanoparticles: A Review

“…Due to their unique properties, these materials find applications in areas, such as medicine, agriculture, information technology, electronics, energy, and environmental protection [15]. (c) 2D: ZnO-NiO nanosheets [18]; and (d) 3D: PA6 nonwoven structure [19]. All reproduced from articles distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.…”

“… Different material structures. ( a ) 0D: SiO nanoparticles [ 16 ]; ( b ) 1D: CoO nanowires [ 17 ]; ( c ) 2D: ZnO–NiO nanosheets [ 18 ]; and ( d ) 3D: PA6 nonwoven structure [ 19 ]. All reproduced from articles distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.…”