Characterization of Ag-doped ZnO thin films by spray pyrolysis and its using in enhanced photoelectrochemical performances

The Effect of Solvent-Modification on the Physicochemical Properties of ZnO Nanoparticles Synthesized by Sol-Gel Method

This study investigated the solvent effect on the synthesis of Zinc Oxide (ZnO) nanoparticle using sol-gel method. Zinc acetate dihydrate and oxalic acid were used as a chemical precursor for the synthesis of the ZnO nanoparticle considering the effects of various solvents. The effect of using water, propanol, or ethanol as solvent during the synthesis were examined. The resultant gel in the aqueous and organic moderate solvent was thermally cracked into ZnO nanoparticles at 450 °C under atmospheric pressure. The results showed that the solvent type has a significant effect on the morphology and particles size of the ZnO nanoparticles synthesized. Atomic Force Microscopy (AFM) was used to investigate the microstructure of the nanoparticles. The crystalline and chemical structure of the prepared ZnO nanoparticle were studied by X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). The average diameter of nano-size particles obtained for ethanol, propanol and water are 79.55 nm, 83.86 nm and 85.59 nm, respectively. ZnO particles showed higher degree of crystalline in water compared to other solvents under current investigation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Highly sensitive photoelectrochemical neuron specific enolase analysis based on cerium and silver Co-Doped Sb2WO6

A signal-enhanced photoelectrochemical immunoassay technique for detecting neuron specific enolase (NSE) was proposed. As a photoactive matrix, (Ce,Ag):Sb₂WO₆ was firstly investigated via doping Ce and Ag into Sb₂WO₆. It could be found that the presence of Ce and Ag not only had enormous variation on the morphology of Sb₂WO₆, but also showed excellent PEC behavior. In order to further improve the visible light utilization rate of (Ce,Ag):Sb₂WO₆, In₂S₃ was modified onto the surface of (Ce,Ag):Sb₂WO₆ to enhance visible light absorption. In addition, the CdS/PDA was served as a secondary antibody marker to further amplify signal. Especially, PDA as an electron donor could effectively remove photogenerated holes. Meanwhile, the good matching cascade band-edge levels between CdS and Sb₂WO₆ could promote photoelectron migration, improve the PEC response, and achieve sensitive detection of NSE. Under the selected excellent conditions, the photocurrent can linearly increase with the increase of NSE concentration in the operating range from 0.1 pg/mL to 50 ng/mL, and the limit of detection is 1.57 fg/mL. The constructed immunosensor also exhibits satisfactory stability, selectivity, and reproducibility, and it creates conditions for the detection of other biomolecules.

Preparation of uniform gold nanoparticles of different quantity deposited on zinc oxide nanorods for photoelectrochemical water splitting

For the photocatalytic test, gold nanoparticles (AuNPs) were prepared using trisodium citrate dehydrate (TCD), following which they were combined on the surface of zinc oxide (ZnO) to prepare ZnO decorated with uniform AuNPs (ZnO/AuNP) photocatalysts. The photocatalytic performance with the ZnO/AuNP was estimated through the rhodamine B (RB) dye degradation under solar irradiation. ZnO/AuNP-30 showed the greatest photocatalytic performance, achieving dye degradation efficiency up to 78.65%. Photoelectrochemical (PEC) measurements were performed using the ZnO/AuNP photoanodes. With AuNP doping amounts of 10, 20, and 30 mL on the ZnO surface, photocurrent densities of 47.46, 63.74, and 68.64 mA cm^-2, respectively, were achieved at an applied voltage of 1.5 V. These values indicated that the doping of AuNPs on the ZnO surface is advantageous for enhancing its PEC water-splitting activity. The highest solar-to-hydrogen (STH) efficiency is 22% with the ZnO/AuNP-30 photoanode at an applied voltage of 0.88 V. The interfacial charge-transfer resistances at the interface were 40 and 2.2 kΩ cm² for the ZnO and ZnO/AuNP-30 photoanodes, respectively.