Synthesis of N-rGO-MWCNT/CuCrO2 Catalyst for the Bifunctional Application of Hydrogen Evolution Reaction and Electrochemical Detection of Bisphenol-A

Abstract

A glassy carbon electrode (GCE) coated with delafossite CuCrO2 loading on the nitrogen-doped reduced graphene oxide (N-rGO) and multiwalled carbon nanotubes (MWCNT) composite (N-rGO-MWCNT/CuCrO2) was applied to the hydrogen evolution reaction and Bisphenol-A (BPA) detection. First, the N-rGO-MWCNT composite was prepared by in situ chemical reduction with caffeic acid as a reducing agent. Then, CuCrO2 was accumulated on the N-rGO-MWCNT surface to form N-rGO-MWCNT/CuCrO2 composite. The morphology structure of the N-rGO-MWCNT/ CuCrO2 composite was analyzed by different characterization techniques. Besides, the GCE/N-rGO-MWCNT/CuCrO2 composite electrode was investigated for hydrogen evolution reaction (HER), which shows an excellent electrocatalytic activity with a low over-potential, increasing reduction current, and a small Tafel slope of 62 mV·dec−1 at 10 mA·cm−2 with long-term stability. Moreover, the electrochemical determination of BPA was in the range of 0.1-110 µM, and low detection limit of 0.033 µM (S/N = 3) with a higher sensitivity of 1.3726 µA µM−1 cm−2. Furthermore, the prepared GCE/N-rGO-MWCNT/CuCrO2 electrode shows effective detection of BPA in food samples with acceptable recoveries. Hence, the finding of GCE/N-rGO-MWCNT/CuCrO2 can be observed as an impressive catalyst to the electrocatalytic activity of HER and BPA oxidation.

Electrochemical Nanoaptasensor Based on Graphitic Carbon Nitride/Zirconium Dioxide/Multiwalled Carbon Nanotubes for Matrix Metalloproteinase-9 in Human Serum and Saliva

“…In Figure 2C, the FESEM image of MWCNTs showed an entwined tubular structure. 57 FESEM images of the ZrO 2 nanoparticles showed agglomerated spherical structures in Figure 2D. In Figure 2E, MWCNTs and ZrO 2 showed firm adherence to g-C 3 N 4 (the red box denotes MWCNTs, whereas the yellow circles signify ZrO 2 ).…”

Blood Oxygen Sensor Using a Boron-Doped Diamond Electrode

“…In order to study the reduction mechanism in detail at −1.4 V ( vs Ag/AgCl), CV curves at various scan rates were obtained in the range of 10–100 mV s –1 . − The potential range used was from 0 to −2 V ( vs Ag/AgCl), as shown in Figure . The electron number was calculated from the slope of the linear relationship between peak currents and scan rates, as represented using the Randles Sevick Equation , for an irreversible process ()­ in which I p is the peak current (ampere), n is the number of electrons, α is the charge transfer coefficient, n α is the number of electrons involved in the charge transfer step, D is the diffusion coefficient (cm 2 s –2 ), A is the area of the electrode surface (0.636 cm 2 ), v is the scan rate (V s –1 ), and C is the concentration in the bulk solution (mol cm –3 ).…”

Environmental Remediation of Toxic Organic Pollutants Using Visible-Light-Activated Cu/La/CeO2/GO Nanocomposites

“…Modified Hummers' preparation techniques were used to prepare the graphene oxide (GO) [30]. In this experiment, 10 g of graphite powder was introduced into concentrated sulfuric acid (100 mL) with 2 g of sodium nitrate and stirred in an ice-water bath to control the solution temperature.…”