Hierarchical nanowire and nanoplate-assembled NiCo2O4-NiO biphasic microspheres as effective electrocatalysts for oxygen evolution reaction

Date

2019-12-01

Author

Cetin, A.
Esenturk, E. N.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

125
views

0
downloads

In this study, NiCo2O4-NiO nanomaterials with two different morphologies were synthesized using urea and cetyltrimethylammonium chloride (CTAC) as structure directing agents. A combination of analytical techniques including XRD, XPS, SEM-EDX, TEM, and BET were utilized for the characterization of the materials. Microscopy images show that urea-stabilized NiCo2O4-NiO (UeNiCo) has urchin-like morphology assembled by nanowires, and CTAC stabilization (C-NiCo) led to the formation of microspheres with nanoplate assembly. In addition, both wires and plates are formed by the assembly of individual NiCo2O4-NiO nanoparticles. Then, glassy carbon electrodes were modified with these hierarchical nanomaterials, and their electrochemical behavior in oxygen evolution reaction was investigated in 0.1 M KOH solution. Although both of the materials had similar onset potentials (1.56 V vs RHE for U-NiCo and 1.57 V vs RHE for C-NiCo), U-NiCo could drive 10 mA cm(-2) of current density at a lower overpotential value (387 mV) than C-NiCo (430 mV). Both of the materials demonstrated impressive kinetic performance with low Tafel slopes (49 mV dec(-1) for U-NiCo and 44 mV dec(-1) for C-NiCo) and good stability during long-term constant potential electrolysis. In addition, NiCo2O4-NiO nanomaterials outperformed RuO2 at high catalytic current densities (i.e., eta(50) = 518 mV for U-NiO and eta(50) = 622 mV for RuO2).

Subject Keywords

Water oxidation, NiCo2O4, Metal oxide, Spinel

URI

https://hdl.handle.net/11511/64805

Journal

MATERIALS TODAY CHEMISTRY

DOI

https://doi.org/10.1016/j.mtchem.2019.100215

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Syntheses of conducting polymers of 3-ester substituted thiophenes and characterization of their electrochromic properties Çamurlu, Pınar; Toppare, Levent Kamil; Department of Chemistry (2006) In this study three different 3-ester substituted thiophene monomers were synthesized via esterification reaction of 3-thiophene ethanol with adipoyl chloride or sebacoyl chloride or octanoyl chloride in the presence of triethylamine at 00C. Characterizations of the monomers were performed by 1H-NMR, 13C-NMR, FTIR, DSC, TGA techniques. Electrochemical behavior of the monomers both in presence or absence of BFEE were studied by cyclic voltammetry. Results showed the astonishing effect of BFEE on the polymeri...
Impact modified poly(ethylene terephthalate)-organoclay nanocomposites Alyamaç, Elif; Yılmazer, Ülkü; Department of Chemistry (2004) This study was conducted to investigate the effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of poly(ethylene terephthalate), organoclay, and an ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) terpolymer acting as an impact modifier for PET. In this context, first, the optimum amount of the impact modifier was determined by melt compounding binary PET-terpolymer blends in a corotating twin-screw extruder. The amoun...
Partial oxidation of methane on the SiO2 surface - A quantum chemical study Ozturk, S; Onal, I; Senkan, S (2000-02-01) Reaction pathways for methane partial oxidation (MPO) on silica were theoretically investigated using the semiempirical MOPAC-PM3 molecular orbital method. The surface of SiO2 was modeled by a helical Si6O18H12 molecular cluster that also exhibits a strained siloxane bridge defect. First, a bond energy analysis was performed on the silica cluster with isolated 3- and 4-coordinated Si surface atoms. Calculated bond dissociation energies for Si-H, SiO-H, and SI-OH were comparable to H-CH3, H-OH, and O-O. In t...
Direct synthesis of Mg-Ni compounds from their oxides Tan, Serdar; Aydınol, Mehmet Kadri; Öztürk, Tayfur; Karakaya, İshak (2010-08-13) A study was carried out on the synthesis of Mg-Ni compounds as well as on the extraction of pure Ni and Mg from their oxides using the method of electro-deoxidation. The oxides sintered at 1200 degrees C were in the form of discrete phases NiO and MgO, suitably proportioned to yield Ni, MgNi2, Mg2Ni and Mg. The oxides were electrolyzed at 3.2 V in a eutectic mixture of CaCl2-NaCl solution maintained at a constant temperature (900-600 degrees C), using a graphite anode. The study has shown that NiO rich mixt...
Regioselectivity observed in manganese(III) acetate mediated addition of acetylacetone to various alkenes: mechanistic and theoretical studies Ceyhan, Selin; Cetinkaya, Yasin; Akdağ, Akın; BALCI, METİN (2016-10-27) Various alkenes substituted at the 1,2-positions by 2-thiophenyl, 3-thiophenyl, and phenyl substituted by electron-withdrawing and electron-donating groups were treated with acetylacetone in the presence of Mn(OAc)(3) in acetic acid. In cases where the thiophene ring was connected at the C-2 carbon atom to the double bond, a single regioisomer was formed whereas in case of substitution at the C-3 positions two regioisomers were formed. Stilbene derivatives also gave two regioisomers under the same reaction ...

Citation Formats

A. Cetin and E. N. Esenturk, “Hierarchical nanowire and nanoplate-assembled NiCo2O4-NiO biphasic microspheres as effective electrocatalysts for oxygen evolution reaction,” MATERIALS TODAY CHEMISTRY, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64805.