Copper-Doped Cobalt Spinel Electrocatalysts Supported on Activated Carbon for Hydrogen Evolution Reaction

Abstract

The development of electrocatalysts based on the doping of copper over cobalt spinel supported on a microporous activated carbon has been studied. Both copper–cobalt and cobalt spinel nanoparticles were synthesized using a silica-template method. Hybrid materials consisting of an activated carbon (AC), cobalt oxide (Co3O4), and copper-doped cobalt oxide (CuCo2O4) nanoparticles, were obtained by dry mixing technique and evaluated as electrocatalysts in alkaline media for hydrogen evolution reaction. Physical mixtures containing 5, 10, and 20 wt.% of Co3O4 or CuCo2O4 with a highly microporous activated carbon were prepared and characterized by XRD, TEM, XPS, physical adsorption of gases, and electrochemical techniques. The electrochemical tests revealed that the electrodes containing copper as the dopant cation result in a lower overpotential and higher current density for the hydrogen evolution reaction.

NiMoO4@Co3O4 Core–Shell Nanorods: In Situ Catalyst Reconstruction toward High Efficiency Oxygen Evolution Reaction

“…[9] The pattern reveals the formation of NiMoO 4 .xH 2 O referenced by PDF# 04-017-0338, a triclinic (Anorthic) crystal structure in agreement with previously published results. [9] After coating with Co 3 O 4 via ALD , the XRD pattern presents additional peaks at 2θ = 19.6°, 31 [10,11] while the peaks at 42.3° and 61.5° pertain to the (200) and (220) planes of rock-salt CoO. [11] Due to the low-temperature deposition (150 °C followed by annealing to 300 °C), the as-prepared film contains CoO phases, in agreement with the literature.…”

“…[11] Due to the low-temperature deposition (150 °C followed by annealing to 300 °C), the as-prepared film contains CoO phases, in agreement with the literature. [10,12] We annealed the hydrous sample at 550 °C to see the changes in the crystal structure. The XRD spectra of the hydrous NiMoO 4 and annealed NiMoO 4 samples are reported in Figure S2 in the Supporting Information.…”

Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments

“…AB 2 X 4 . [801][802][803][804][805][806] Peng et al studied a spinel-based nanowire electrode system for full water electrolysis. 796 NiCo 2 O 4 nanowires, subjected to sulphuration to yield Ni 0.33 Co 0.67 S 2 nanowires (Fig.…”

Transition metal oxides with perovskite and spinel structures for electrochemical energy production applications

“…Carbon materials are excellent candidates to fulfil this role taking into account their interesting properties such as high electrical conductivity, high thermal stability, high surface area, and, in some cases, low price. Different types of carbon materials have been used for this purpose, such as carbon blacks (De Koninck et al, 2007;Kéranguéven et al, 2015), carbon nanotubes (Alexander et al, 2018;Zhang et al, 2020e;Li et al, 2019), graphene-based materials (Hu et al, 2015;Samanta and Raj, 2019;Rebekah et al, 2020;Zhuang et al, 2021), activated carbons (Hu et al, 2018;Flores-Lasluisa et al, 2019b) and nitrogen-doped carbon materials (Chen et al, 2017;Park et al, 2015;Najam et al, 2020;Wu et al, 2018b;Mathumba et al, 2020;Liu et al, 2021). Nevertheless, no sufficient attention is paid to the effect of the structure (at different levels) and surface chemistry of the carbon material on the interaction with the metal oxide and on its role on the catalytic activity improvement.…”