Co(OH)2 Nanoflowers Decorated α-NiMoO4 Nanowires as a Bifunctional Electrocatalyst for Efficient Overall Water Splitting

Abstract

The development of bifunctional electrocatalysts with high catalytic activity and cyclic stability is an effective method for electrocatalytic water splitting. Herein, a promising hydroxide/oxide Co(OH)2/α-NiMoO4 NWs/CC heterostructure with nanoflowers decorating the nanowires was fabricated on a carbon cloth (CC) substrate via hydrothermal and calcination methods. In contrast to one-dimensional nanomaterials, the interfaces of Co(OH)2 nanoflowers and α-NiMoO4 nanowires on CC provide more active sites for electrocatalytic reactions; therefore, they exhibit obviously enhanced electrocatalytic activities in overall water splitting. Specifically, the Co(OH)2/α-NiMoO4 NWs/CC electrodes exhibit an overpotential of 183.01 mV for hydrogen evolution reaction (HER) and of 170.26 mV for oxygen evolution reactions (OER) at the current density of 10 mA cm−2 in 1.0 M KOH. Moreover, the electrocatalytic oxygen evolution reaction (OER) activity of the Co(OH)2/α-NiMoO4 NWs/CC electrocatalyst was enhanced after long-term stability tests.

Exploring the potential of cobalt hydroxide and its derivatives as a cost-effective and abundant alternative to noble metal electrocatalysts in oxygen evolution reactions: a review

“…Nevertheless, this electrode has the potential for use in various other elds. 179,180 The study performed by He et al 181 is focused on the electrochemical performance of as-fabricated catalysts towards the OER in 0.1 M KOH electrolyte. The catalysts studied include sol-gel-derived SFM, as-spun SFM nanowires (SFM-NF), bare SFM hollow nanobers, and Co(OH) 2 /SFM-NF.…”

2D bifunctional tungsten disulfide-embedded UiO-66 (WS2@UiO-66) as a highly active electrocatalyst for water splitting

“…Since the oxidation reaction has occurred and the state of the metal is changed, this changed electronic configuration will now take part in the OER. [56][57][58][59][60][61][62] The overpotential is measured and compared at 100 mA cm À2 . WS 2 @UiO-66(1 : 2) requires an overpotential of around about 550 mV to attain 100 mA cm À2 current density, which is less than bulk WS 2 (650 mV), exfoliated WS 2 (610 mV), WS 2 @UiO-66(1 : 1) (570 mV), and WS 2 @UiO-66(1 : 3) (570 mV).…”

Metal-Oxides- and Metal-Oxyhydroxides-Based Nanocomposites for Water Splitting: An Overview

“…The theoretical calculations and experimental results showed that Ni-O-Fe structures offer exceptional catalytic activity in terms of oxygen electrochemistry [ 128 ]. Xu et al [ 129 ] developed cobalt hydroxide nanoflowers-decorated α-NiMoO 4 nanowires as functional electrocatalysts for water splitting reactions. They decorated the Co(OH) 2 /NiMoO 4 nanowires on a carbon cloth via a simple HT process, which formed as one-dimensional nanoarchitectures, providing a lower overpotential toward the HER of 183 mV and the OER of 170 mV at a current density of 10 mA cm −2 in 1.0 M KOH electrolytes, showing good long-term stability.…”