Electrochemical Sensing Platform Based on Functionalized Multi-Walled Carbon Nanotubes and Metal Oxide for the Detection and Degradation Studies of Orange II Dye

Abstract

Textile industry effluents are heavily contaminated with dyes. The discharge of these toxic dyes into waterbodies poses a serious threat to aquatic flora and fauna. The ultimate entrance of these toxins from thereon into the food chain affects the primary and secondary consumers. Therefore, the adoption of a sustainable solution for protection against the detrimental effects associated with adulterated water is an immediate need of the hour. To address the severity of the issue, the present work aims to design an electrochemical sensing platform by modifying the glassy carbon electrode (GCE) with zinc oxide nanoparticles and amino group-functionalized multi-walled carbon nanotubes (NH 2 -fMWCNTs) for the detection of Orange II, which is a toxic azo dye. Zinc oxide nanoparticles facilitate electron transfer between the transducer and the analyte. While, the positively charged NH 2 -fMWCNTs in acidic medium help in preconcentration of negatively charged analyte molecules at the electrode/electrolyte interface. The modification of the GCE catalyzed the oxidation of Orange II, as evidenced by the negative shift of the oxidation potential and enhancement in peak current intensity. Square wave voltammetry was used to optimize various experimental conditions, such as the supporting electrolyte, pH of the electrolyte, deposition potential, and deposition time for the best performance of the designed sensor. Under the optimized conditions, the detection limit and quantification of the designed sensor were found to be 0.57 and 1.92 nM, respectively. The catalytic degradation studies of Orange II was shown to be facilitated by titanium dioxide, which acted as a photocatalyst. The addition of hydrogen peroxide further promoted the extent and rate of degradation of dye. The breakdown of Orange II was probed by the designed sensing platform electrochemically and also by UV–visible spectroscopy. The dye degraded up to 92% by following pseudo-first-order kinetics.

Photoelectrocatalytic Detection and Degradation Studies of a Hazardous Textile Dye Safranin T

“…To ascertain the type of the reaction, cyclic voltammograms were recorded at various scan rates, and then the plot of the log of peak current versus the log of scan rate was used to determine the nature of the reaction. A review of the literature shows that if the slope of the plot between log I p versus log υ is 0.5 or greater, the process should be governed by diffusion, and if it is closer to 1, it should be controlled by adsorption [13]. The effect of scan rates on the electrocatalytic behavior of COOH-f MWCNTs/Fe-ZnO/GCE towards the oxidation of ST was studied in 0.1 M PBS solution.…”

“…The untreated discharge of dyes loaded effluents reduce photosynthesis in aqueous ecosystems leading to the extinction of aquatic biota [10,11]. A number of dyes have been reported to cause jaundice, tumors, skin infections, and allergic reactions [12][13][14][15]. Some dyes are carcinogenic and mutagenic [16,17].…”

Recent trends in nanostructured carbon-based electrochemical sensors for the detection and remediation of persistent toxic substances in real-time analysis

“…Furthermore, to monitor Orange II, a dangerous azo dye, Irfan et al [91] created an electrochemical sensing system by altering the GCE using zinc oxide NP and amino group-functionalized MWCNTs (NH2-fMWCNTs). The transducer and analyte can transmit electrons more easily because of zinc oxide NPs.…”

Electrochemical detection and removal of brilliant blue dye via photocatalytic degradation and adsorption using phyto-synthesized nanoparticles

“…Moreover, previous studies have demonstrated the enhanced sensitivity of the modified electrode resulting from the combined use of MWCNTs and NPs. 7 This phenomenon can be ascribed to the substantial increase in surface area facilitated by the NPs. ZnO is an important semiconductor material that generally has an exciton binding energy of roughly 60 meV and possesses a 3.37 eV band gap energy in normal conditions.…”