Due to its wide applications, the determination of H₂O₂ concentration became an important research topic in recent years. Electrochemical sensors based on nanomaterials have been applied to the detection of H₂O₂ [1]. Among various nanomaterials, silver nanoparticles (Ag_NPs) with controllable dimension and size distribution attracted much attention because of their excellent catalytic [2] and electric properties [3]. Recently, photochemical reduction of Ag ions, induced by semiconductor materials, is of great interest since the silver loading and overall surface area can be easily controlled by tuning the conditions of the photochemical reaction and the surface morphology of semiconductor template, respectively.

In this study, a Ag_NPs/zinc oxide modified electrode was fabricated and its electrocatalytic properties towards H₂O₂ were investigated. The zinc oxide nanorods (ZnO_NRs) were first grown onto the FTO glass, which is denoted as ZnO_NRs/FTO electrode, covered by a ZnO seed layer by using chemical bath method. Thereafter, the Ag_NPs were deposited onto the ZnO_NRs/FTO electrode by photo-reducing Ag⁺ ions with the aid of UV irradiation (λ=365 nm) for 5 min, donated as Ag_NPs/ZnO_NRs/FTO. Compared to the ZnO_NRs/FTO electrode, a well pronounced peak at -0.62 V (vs. Ag/AgCl/KCl sat'd.) resulting from the reduction of H₂O₂ was observed on the Ag_NPs/ZnO_NRs/FTO electrode. Besides, when Ag_NPs was deposited onto the mesoporous ZnO film (ZnO_meso) in the presence of eosin Y, the resulting Ag_NPs/ZnO_meso/FTO electrode showed higher catalytic current to H₂O₂ than that in the absence of eosin Y. This behavior can be attributed to the higher loading of Ag_NPs on the ZnO_meso film. In order to increase the loading of Ag_NPs, thus enhancing the sensor sensitivity, the effect of the eosin Y concentration and the conditions of the photochemical reaction were under investigation.

[1] S. Wu, H. Zhao, H. Ju, C. Shi, J. Zhao, Electrochem. Commun. 8 (2006) 1197.

[2] C. M. Welch, C. E. Banks, A. O. Simm, R. G. Compton, Anal. Bioanal. Chem. 382 (2005) 12.

[3] A. Balamurugan, S. M. Chen, Electroanalysis 21 (2009) 1419.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/21903 must be provided.

1. Increasing the surface area of electrodeposited-Pt through adding surfactant for dye-sensitized solar cell application
2. Chemiresistive-type NO gas sensor based on in-situ synthesized poly(3,4-ethylenedioxythiophene) film