Phase-controllable synthesis of cobalt hydroxide for electrocatalytic oxygen evolution

2017 ◽  
Vol 46 (32) ◽  
pp. 10545-10548 ◽  
Author(s):  
Fenglei Lyu ◽  
Yaocai Bai ◽  
Qingfa Wang ◽  
Li Wang ◽  
Xiangwen Zhang ◽  
...  

Identification of active sites for oxygen evolution reaction (OER) plays a key role in the design and fabrication of high-performance cobalt-based electrocatalysts.

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaili Zhang ◽  
Xinhui Xia ◽  
Shengjue Deng ◽  
Yu Zhong ◽  
Dong Xie ◽  
...  

Abstract Controllable synthesis of highly active micro/nanostructured metal electrocatalysts for oxygen evolution reaction (OER) is a particularly significant and challenging target. Herein, we report a 3D porous sponge-like Ni material, prepared by a facile hydrothermal method and consisting of cross-linked micro/nanofibers, as an integrated binder-free OER electrocatalyst. To further enhance the electrocatalytic performance, an N-doping strategy is applied to obtain N-doped sponge Ni (N-SN) for the first time, via NH3 annealing. Due to the combination of the unique conductive sponge structure and N doping, the as-obtained N-SN material shows improved conductivity and a higher number of active sites, resulting in enhanced OER performance and excellent stability. Remarkably, N-SN exhibits a low overpotential of 365 mV at 100 mA cm−2 and an extremely small Tafel slope of 33 mV dec−1, as well as superior long-term stability, outperforming unmodified sponge Ni. Importantly, the combination of X-ray photoelectron spectroscopy and near-edge X-ray adsorption fine structure analyses shows that γ-NiOOH is the surface-active phase for OER. Therefore, the combination of conductive sponge structure and N-doping modification opens a new avenue for fabricating new types of high-performance electrodes with application in electrochemical energy conversion devices.


Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 459 ◽  
Author(s):  
Heng Luo ◽  
Hang Lei ◽  
Yufei Yuan ◽  
Yongyin Liang ◽  
Yi Qiu ◽  
...  

The rational design and development of the low-cost and effective electrocatalysts toward oxygen evolution reaction (OER) are essential in the storage and conversion of clean and renewable energy sources. Herein, a ternary copper-cobalt sulfide nanosheets electrocatalysts (denoted as CuCoS/CC) for electrochemical water oxidation has been synthesized on carbon cloth (CC) via the sulfuration of CuCo-based precursors. The obtained CuCoS/CC reveals excellent electrocatalytic performance toward OER in 1.0 M KOH. It exhibits a particularly low overpotential of 276 mV at current density of 10 mA cm−2, and a small Tafel slope (58 mV decade−1), which is superior to the current commercialized noble-metal electrocatalysts, such as IrO2. Benefiting from the synergistic effect of Cu and Co atoms and sulfidation, electrons transport and ions diffusion are significantly enhanced with the increase of active sites, thus the kinetic process of OER reaction is boosted. Our studies will serve as guidelines in the innovative design of non-noble metal electrocatalysts and their application in electrochemical water splitting


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3010
Author(s):  
Sergio Battiato ◽  
Mario Urso ◽  
Salvatore Cosentino ◽  
Anna Lucia Pellegrino ◽  
Salvo Mirabella ◽  
...  

The low efficiency of water electrolysis mostly arises from the thermodynamic uphill oxygen evolution reaction. The efficiency can be greatly improved by rationally designing low-cost and efficient oxygen evolution anode materials. Herein, we report the synthesis of Ni–P alloys adopting a facile electroless plating method under mild conditions on nickel substrates. The relationship between the Ni–P properties and catalytic activity allowed us to define the best conditions for the electroless synthesis of highperformance Ni–P catalysts. Indeed, the electrochemical investigations indicated an increased catalytic response by reducing the thickness and Ni/P ratio in the alloy. Furthermore, the Ni–P catalysts with optimized size and composition deposited on Ni foam exposed more active sites for the oxygen evolution reaction, yielding a current density of 10 mA cm−2 at an overpotential as low as 335 mV, exhibiting charge transfer resistances of only a few ohms and a remarkable turnover frequency (TOF) value of 0.62 s−1 at 350 mV. The present study provides an advancement in the control of the electroless synthetic approach for the design and large-scale application of high-performance metal phosphide catalysts for electrochemical water splitting.


2020 ◽  
Vol 4 (4) ◽  
pp. 1863-1874 ◽  
Author(s):  
Bezawit Z. Desalegn ◽  
Harsharaj S. Jadhav ◽  
Jeong Gil Seo

Heterostructuring assisted trimetallic transition metal phoshide with in situ generated active sites, exhibits superior catalytic activity towards oxygen evolution reaction in alkaline medium.


Author(s):  
Pratik V. Shinde ◽  
Rutuparna Samal ◽  
Chandra Sekhar Rout

AbstractElectrocatalytic oxygen evolution reaction (OER) is one of the crucial reactions for converting renewable electricity into chemical fuel in the form of hydrogen. To date, there is still a challenge in designing ideal cost-effective OER catalysts with excellent activity and robust durability. The hybridization of transition metal oxides and carbonaceous materials is one of the most effective and promising strategies to develop high-performance electrocatalysts. Herein, this work synthesized hybrids of NiFe2O4 spinel materials with two-dimensional (2D) graphene oxide and one-dimensional (1D) carbon nanotubes using a facile solvothermal approach. Electrocatalytic activities of NiFe2O4 with 2D graphene oxide toward OER were realized to be superior even to the 1D carbon nanotube-based electrocatalyst in terms of overpotential to reach a current density of 10 mA/cm2 as well as Tafel slopes. The NiFe2O4 with 2D graphene oxide hybrid exhibits good stability with an overpotential of 327 mV at a current density of 10 mA/cm2 and a Tafel slope of 103 mV/dec. The high performance of NiFe2O4 with 2D graphene oxide is mainly attributed to its unique morphology, more exposed active sites, and a porous structure with a high surface area. Thus, an approach of hybridizing a metal oxide with a carbonaceous material offers an attractive platform for developing an efficient electrocatalyst for water electrochemistry applications.


2021 ◽  
Author(s):  
Ning Liu ◽  
Qiaoqiao Zhang ◽  
Jingqi Guan

Seeking for low-cost and high-performance electrocatalysts for oxygen evolution reaction (OER) has drawn enormous research interest in the last few years. Reported herein is the topotactic construction of a binuclear...


Author(s):  
Shuya Zhao ◽  
Yurui Xue ◽  
Zhongqiang Wang ◽  
Zhiqiang Zheng ◽  
Xiaoyu Luan ◽  
...  

Developing highly active, stable and low-cost electrocatalysts capable of an efficient oxygen evolution reaction (OER) is urgent and challenging.


2021 ◽  
Author(s):  
Shuai Wang ◽  
Zheng Lu ◽  
Yuan Fang ◽  
Tian Zheng ◽  
Zidong Zhang ◽  
...  

Rational construction of self-supporting electrode has been extensively investigated in energy conversion and storage. Herein, hierarchical N-doped carbon encapsulated Ni3S2 grown on 3D porous Ni foam (H-Ni3S2@NC/NF) is controllably synthesized...


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