Synthesis of ZnO/CNT Nanocomposites for Ultraviolet Sensors

Abstract

Zinc oxide/carbon nanotube (ZnO/CNTs) nanocomposites are developed on gold (Au)-coated unpolished Si p-type (100) substrates with 2, 4, 6, 8, and 10 nm thicknesses by vapor–liquid–solid method. One set of Au-coated Si substrates are annealed to develop Si–Au samples for better nucleation. XRD, FE-SEM, Raman, and photoluminescence spectroscopic characterizations are used to study structural, morphological, and optical properties on annealed and unannealed catalyst layers with various Au thickness samples. In XRD results, the ZnO/CNT nanocomposites are observed with higher crystallinity and purity of phase. FE-SEM images showed variety of nanostructures with variation in morphologies with respect to Au thickness in annealed and unannealed samples. Clear indication of high defect concentrations and high crystallinity is observed in Raman spectra. It is observed in PL spectra that preferred peak orientation with shift ∼4 nm in the unannealed Au layer and ∼9 nm in annealed Au layer samples exhibited formation of ZnO/CNT nanocomposites. Efficient sensing is observed in the 6-nm thickness Au layer in the unannealed sample. Annealed Au-coated Si samples at 8 and 10 nm thicknesses showed efficient UV sensing with quick response and recovery time.

10 years of frontiers in carbon-based materials: carbon, the “newest and oldest” material. The story so far

“…In this sense, Matsuo and Araki (2017) prepared hydrophobised pillared carbon thin films from the thermal reduction of graphite oxide silylated with octyltrichlorosilane and then dimethyldichlorosilane, and the obtained pillared carbons were used for the detection of acetone in the presence of water vapour. Basit et al (2022) developed ultraviolet sensors based on ZnO/CNT composites prepared from a vapour-liquid-solid method. That research article included, among other sections, the description of the synthesis of ZnO nanostructures, a detailed characterisation of the samples, the description of the mechanism behind the UVsensing, and the fabrication of the sensor.…”

Carbon-based photoelectrochemical sensors: recent developments and future prospects

“…CNTs can modify their physical/chemical properties by interacting with the molecules in their surrounding environment and exhibit distinct mechanical, electrical, optical, and electromechanical properties, leading to the development of highly selective, responsive, affordable, and sensitive sensors based on the unique CNT structure. Basit et al 94 combined CNTs with ZnO, which exhibited enhanced UV and visible range absorption. When combined with ZnO, the mechanical properties of CNTs resulted in improved mechanical strength in ZnO nanostructures.…”