Research Article Bentonite Nanoclay Optoelectrochemical Property Improvement through Bimetallic Silver and Gold Nanoparticles Sizwe Ngcobo, Bongiwe Silwana , Kanyisa Maqhashu, and Mangaka C. Matoetoe Department of Chemistry, Cape Peninsula University of Technology, Tennant Street, P.O. Box 652, Cape Town, South Africa Correspondence should be addressed to Mangaka C. Matoetoe; lellangm@gmail.com Received 16 May 2022; Revised 20 July 2022; Accepted 8 September 2022; Published 3 October 2022 Academic Editor: Marco Rossi Copyright © 2022 Sizwe Ngcobo et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. is study assesses the physical and electrochemical changes of bimetallic Ag-Au nanoparticle-functionalized bentonite nanoclay. Nanoclay was studied to deduce a better sensing material/film. A chemical co-reduction method was used to synthesize bimetallic Ag-Au c nanoparticles, which were used to prepare a Ag-Au/PGV bentonite composite. Bimetallic Ag-AuNPs and their nanoclay composite were optically characterized using the scanning electron microscope, ultraviolet visible spectroscopy, X-ray diffraction, and Fourier transform infrared, whilst cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to ascertain their electrochemical activity and properties. e results of surface morphological inspection showed an average size of 10 nm, in agreement with XRD. e bimetallic Ag-AuNPs UV/Vis characteristic wavelengths of 414 nm and 516 nm confirmed the presence of Ag and Au metals, respectively. XRD exhibited diffraction planes related to 2θ values of Ag and Au metals, whilst FTIR indicated mainly COO- functional groups from the citrate capping of bimetallic Ag-Au NPs. CV and DPV showed that bentonite nanoclay is largely insulated by silicates but exhibited a small electroactivity of Fe. e electroactivity of Ag-Au/PGV bentonite exhibited peak potentials due to Ag/Ag+ and Au/Au 3+ redox couples at 0.19 V/-0.20 V and 1.37 V/0.42, respectively. e Ag-Au/ PGV bentonite nanocomposite exhibited the highest surface concentration of 3.25 × 10 -2 cm 2 , a diffusion coefficient of 2.36 ×-11 cm 2 /s, and an electron transfer rate constant (Ks) of 1.99 × 10 -4 cm 2 . e outcome of these results indicated that the Ag- Au/PGV bentonite nanocomposite was more electroactive than PGV. erefore, this study accentuates Ag-Au/PGV bentonite nanocomposite as a novel and promising platform for electrochemical sensing with higher sensitivity and efficiency than other sensing materials. 1. Introduction Bentonites are clays generally defined as montmorillonite (MMT), which is the basic and most abundant constituent of bentonite clay [1, 2]. Amongst other components, it consists of smectites, which are layers within the clay holding a negative charge. e layers contain species that include silicates and tetrahedrons that often contain metals such as magnesium, sodium, and iron. Bentonite presents strong colloidal properties, and its volume increases several times when encountering water, creating a gelatinous and viscous fluid [3]. e interesting properties of bentonite (hydration, swelling, water absorption, viscosity, and thixotropy) make it a valuable material for various uses and applications [3]. According to the literature, the large surface area of bentonite clay has led to its having enhanced catalytic properties, cation exchangeability, and chemical stabil- ity. Consequently, bentonite has been successfully used as a sensing material and in the fabrication of electro- chemical sensors to determine pharmaceuticals and toxic metal ions [4]. Moreover, recent advancements have reported studies on bentonite modification for adsorp- tion applications. Various materials have been used as modifiers from organic to inorganic substrates, and a recent study has reported bentonite coated with iron oxide forming a bentonite composite, which was used to remove pollutants in aqueous media [5]. However, the limitations associated with bentonite-ba bentonite-based electrochemical sensors have relatively low sensitivity due to on-transfer capacity. Hindawi Journal of Nanotechnology Volume 2022, Article ID 3693938, 9 pages https://doi.org/10.1155/2022/3693938