Enhanced Electrochemical NO₂⁻Oxidation Reactions on Biomolecule Functionalised Graphene Oxide

Abstract

Herein, electrochemical oxidation of nitrite (NO 2 À ) is demonstrated using metal-free, electrochemically highly stable, and selective biomolecule i. e. tyramine functionalized graphene oxide (GT) electrocatalyst for nitrite oxidation in phosphate buffer at pH-7. The successful functionalization of a biomolecule on graphene is carried out by a simple chemical method. The surface features of biomolecule functionalized graphene oxide were studied by using both spectroscopic and microscopic techniques including scanning electron microscope (SEM) which shows wrinkled and folded structures having a thickness of ∼ 20 nm corresponding to a few layer of graphene. Moreover, their structural analysis was carried out using X-ray photoelectron spectroscopy nitrogen band at peak position of ∼ 400 eV reveals biomolecule functionalization, Fourier-transform infrared spectroscopy (FTIR) reveals significant peak at 1580 cm À 1 corresponding to amine functionalization, Raman Spectroscopy reveals enhanced I D /I G ratio as compared to GO.The electrochemical surface area (ECSA) found tobe 3.60 cm 2 . The as-synthesized electrocatalyst is found to be more active towards electro-oxidation of nitrite (NO 2 À ) at a low onset potential of 0.6 V vs saturated calomel electrode (SCE) from linear sweep voltammetry (LSV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. Moreover, its current stability at a given potential is also tested by chronoamperometric (i-t) measurements within a concentration range of 0 μM to 7 μM and is having long term good electrochemical stability at an onset potential of 0.6 V vs SCE. The onset potential of GT was 0.6 V vs SCE, the limit of detection (LOD) 0.933 μM and high current density 21 mA cm À 2 as compared to GO 8.7 mA cm À 2 . Considering above perspectives, our findings emphasizes the importance of biomolecule functionalised GO is the best electrocatalyst for electrooxidation of nitrites, which is one of the important species for environmental remediation.

Characterisation of a phosphatase-like nanozyme developed by baking cysteine and its application in reviving mung bean sprouts damaged by ash

“…High resolution XPS peaks at 399.1 eV and 400.4 eV for N 1s are identified as N in the form of NH-CO and C-N, respectively. 25,26 The peaks at 530.5 eV and 531.6 eV for O 1s are attributed to O in the form of CO or NH-CO and COO − , respectively. The XPS spectrum of baked cysteine indicates that its main component is cystine, consistent with the FT-IR spectrum and calculations.…”

Electrocatalytic Oxidation of Nitrite Using a Composite of Reduced Graphene Oxide and Cobalt‐4‐Pyridylporphyrin Coordination Polymer

“…Various types of materials have been utilized as electrocatalysts for oxidation and/or detection of nitrite. [25][26][27][28][29][30] Many macromolecules, especially metalloporphyrins, are reported as good electrocatalysts in different forms/matrices. [31][32][33][34] Porphyrins showed good activity towards the oxidation of nitrite.…”

“…In majority of the detection and quantification procedures, nitrite is converted into nitrate through electrocatalysis. Various types of materials have been utilized as electrocatalysts for oxidation and/or detection of nitrite [25–30] . Many macromolecules, especially metalloporphyrins, are reported as good electrocatalysts in different forms/matrices [31–34] .…”

Study on Corrosion Characteristics of Aluminum Alloy Al3102 in Sulfate-reducing Bacteria Environment and Investigating the Use of Azadirachta indica Leaves Extract in its Control

“…O1s spectra of MB sample (Fig.11 (c)) shows a peak at 532 eV corresponding to the C-O groups of the biofilm[30]. The deconvoluted O1s (Fig.11 (d)) spectra for the MBI sample show the presence of esters (533.3 eV) and C-OH (534.7 eV) groups adsorbed onto the Al3102 surface[31]. The N1s spectra for the MB sample (Fig.12) show peaks at 398.5 eV and 400 eV which confirms the metal-N bonds (N-Me) and C-N/C-N-O groups individually, and these findings match well with the…”