Bi2O3 Nanoparticles Decorated Carbon Nanotube: An Effective Nanoelectrode for Enhanced Electrocatalytic 4-Nitrophenol Reduction

Abstract

4-Nitrophenol (4-NP) is present in most industrial waste water resources as an organic pollutant, and is a highly toxic and environmentally hazardous pollutant. Herein, we report that bismuth oxide (Bi 2 O 3 ) decorated multi-walled carbon nanotubes (Bi 2 O 3 @MWCNTs) are the most prominent electrocatalyst for 4-NP electroreduction in acidic conditions. The electrocatalyst is synthesized by a simple chemical reduction method using ethylene glycol as a capping agent. The synthesized Bi 2 O 3 @MWCNTs electrocatalyst has been well-characterized by Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. Bi 2 O 3 @MWCNTs have a cubic structure which is confirmed by XRD. TEM imaging reveals Bi 2 O 3 NPs are ∼2 nm in size, are grown on MWCNTs and that these nanoparticles are active toward 4-NP electroreduction. The electrochemical studies by cyclic voltammetry measurements show that the Bi 2 O 3 @MWCNTs electrocatalyst can sense 4-NP at a very low potential i.e., −0.17 vs. saturated calomel electrode (SCE). Furthermore, electroanalytical parameters like scan rate and concentration dependence were studied with electrochemcial impedance spectroscopy (EIS) and the effect of pH on cathodic current was examined under experimental conditions. The lower limit of detection (LOD) was found to be 0.1 µM for the Bi 2 O 3 @MWCNTs nanomaterial and is excellent toward 4-NP. The present study has applications for reducing water pollution and for sorting out related issues.

Preparation of Electrode Material Based to Bismuth Oxide-Attached Multiwalled Carbon Nanotubes for Lead (II) Ion Determination

“…The E acc , t acc , and pH of the electrolyte were optimized. [23,24]. The XRD patterns of Bi 2 O 3 @CNTs-20, Bi 2 O 3 @CNTs-50, and Bi 2 O 3 @CNTs-70 show increased peak intensities at 2θ = 28:0 °, resulting from the increased Bi 2 O 3 loading [25].…”

Enhanced Electrochemical NO2−Oxidation Reactions on Biomolecule Functionalised Graphene Oxide

“…[13][14][15][16] In recent years metal-based nanocatalyst and its composites have been widely demonstrated for electrocatalytic oxidation of nitrites. [17][18][19][20][21][22][23][24] Large-scale use of metal composite and catalyst results in a high cost which restricts their commercialization. Interestingly, metal-free carbon based electrocatalyst overcomes these side effects/obstacles over metal catalyst systems.…”

“…In recent years metal‐based nanocatalyst and its composites have been widely demonstrated for electrocatalytic oxidation of nitrites [17–24] . Large‐scale use of metal composite and catalyst results in a high cost which restricts their commercialization.…”

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

“…ozone depletion and global warming. [1][2][3][4] It's an alarming situation as the ocean water is changing its pH that could trigger toxic algal blooms and even dead zones in coastal water and soil pollution due to nitrite. Nitrite can affect the plants and animals in an ocean by utilizing/capturing dissolved oxygen and makes local and internal oceanic environment oxygen deficient.…”