Ultrasensitive and bifunctional ZnO nanoplates for an oxidative electrochemical and chemical sensor of NO₂: implications towards environmental monitoring of the nitrite reaction

Abstract

Herein, we focused on the one pot synthesis of ZnO nanoplates (NP edge thickness of ∼100 nm) using a chemical emulsion approach for chemical (direct) and electrochemical (indirect) determination of NO2.

Enhanced Electrochemical NO2−Oxidation Reactions on Biomolecule Functionalised Graphene Oxide

“…Electrochemical impedance spectroscopic (EIS) studies also done in PBS at a pH-7 solution to compare the electron transfer rate between GO and GT as shown in Figure 7(c) as it can be seen that electron transfer is faster on GT/GCE as compared GO/GCE which is found to be low resistance in GT concerning GO could be due to availability of additional anchoring tyramine based functionalities for adsorption of nitrite species form solution. [32,42] These results of electrooxidation and current density profile proves that the GT has been an excellent current and potential stability towards electrochemical nitrite oxidation reaction. The increase in anodic current is due to the conversion of NO 2 À to NO 3 À and could be due to GT/GCE provides larger surface area along with additional anchoring/interacting sites further for species and intermediates to promote towards enhancement in electrocatalytic activity to aggregate the NO 2 À molecules for oxidation.…”

“…Figure 7(b) shows the calibration curve i. e. current density vs concentration of nitrite and the results show clear oxidation waves in support with concentration dependent CV studies. Electrochemical impedance spectroscopic (EIS) studies also done in PBS at a pH‐7 solution to compare the electron transfer rate between GO and GT as shown in Figure 7(c) as it can be seen that electron transfer is faster on GT/GCE as compared GO/GCE which is found to be low resistance in GT concerning GO could be due to availability of additional anchoring tyramine based functionalities for adsorption of nitrite species form solution [32,42] . These results of electrooxidation and current density profile proves that the GT has been an excellent current and potential stability towards electrochemical nitrite oxidation reaction.…”

Heteroatom (N, O, and S)-Based Biomolecule-Functionalized Graphene Oxide: A Bifunctional Electrocatalyst for Enhancing Hydrazine Oxidation and Oxygen Reduction Reactions

“…The superimposed Brunauer−Emmett−Teller (BET) surface area N 2 adsorption−desorption isotherms of L-Cy-rGO having a type-IV isotherm giving to IUPAC classification, conforming to microporous solid. 69,70 The specific surface area (S BET ) and specific volume of L-Cy-rGO are 33.719 m 2 /g and 0.077 cc/g, respectively, determined from the data shown in Figure 6a. Also, the pore volume distribution curves attained by the Barrett−Joyner−Halenda (BJH) method indicate the presence of a mesoporous structure for L-Cy-rGO with maximum pore volume for a pore diameter of 1.53 nm for L-Cy-rGO as shown in Figure 6b.…”

Synthesis of Metal‐Free Nanoporous Carbon with Few‐Layer Graphene Electrocatalyst for Electrochemical NO2− Oxidation

“…[15] The literature review reflects that, the selective oxidation of NO 2 À is very difficult, because of having multiple intermediate formation and during the electrochemical oxidation of NO 2 À . [16] To overcome these issues numerous efficient electrocatalytic systems are established such as carbon-based nanomaterials including carbon nanotube, graphene oxide, Fullerene (C 60 ), MOF based carbon dots and are further modified by metallic, bimetallic, and polymer based systems [17,18] and their hybrids such as MWCNTs@rGO, NRs, [19] rGOÀ Co 3 O 4 @Pt nanocomposite, [20] rGO-C 60 /Au NPs, [21] modified electrodes for electrochemical detection of NO 2 À . In general, these above NCs based systems and their hybrids are commonly used for the removal of organic dyes and pollutants from environmental, industrial, and laboratory-based waste products.…”