Oxygen vacancies confined in Co3O4 quantum dots for promoting oxygen evolution electrocatalysis

2019 ◽  
Vol 6 (8) ◽  
pp. 2055-2060 ◽  
Author(s):  
Yun Tong ◽  
Hainiao Mao ◽  
Yanglei Xu ◽  
Jiyang Liu
Keyword(s):  
Quantum Dots ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Oxygen Vacancies

Abundant oxygen vacancies confined in Co3O4 quantum dots provide more efficient Co(ii), more active sites and improved conductivity for superior OER performance.

Oxygen vacancy-confined CoMoO4@CoNiO2 nanorod arrays for oxygen evolution with improved performance

2019 ◽  
Vol 48 (27) ◽  
pp. 10116-10121 ◽  
Author(s):  
Xiaoqiang Du ◽  
Guangyu Ma ◽  
Xiaoshuang Zhang
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Evolution ◽  
Adsorption Energy ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Dft Calculation ◽  
Catalytic Properties ◽  
Nanorod Arrays ◽  
Calculation Results ◽  
Improved Performance

Experimental and DFT calculation results show that the presence of oxygen vacancies can decrease the adsorption energy of intermediates at active sites and facilitate the adsorption of intermediates, thus improving the catalytic properties.

Dual-doping of ruthenium and nickel into Co3O4 for improving the oxygen evolution activity

2020 ◽  
Vol 4 (5) ◽  
pp. 1390-1396 ◽  
Author(s):  
Beibei Guo ◽  
Ruguang Ma ◽  
Zichuang Li ◽  
Jun Luo ◽  
Minghui Yang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Intrinsic Activity ◽  
Ni Doping ◽  
One Step ◽  
Ru Doping ◽  
Co Doped

Ru and Ni co-doped Co3O4 with improved OER activity were synthesized by a one-step hydrothermal method. Ru doping increases the intrinsic activity, while Ni doping creates more oxygen vacancies and exposes more active sites.

Role of Specific N-Containing Active Sites in Interconnected Graphene Quantum Dots for the Enhanced Electrocatalytic Activity towards Oxygen Evolution Reaction

2017 ◽  
Vol 2 (31) ◽  
pp. 9943-9946 ◽  
Author(s):  
Sumana Kundu ◽  
Bibhudatta Malik ◽  
Deepak K. Pattanayak ◽  
Pitchai Ragupathy ◽  
Vijayamohanan K. Pillai
Keyword(s):  
Quantum Dots ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Electrocatalytic Activity ◽  
Active Sites ◽  
Graphene Quantum Dots

A mild reduction of Co-doped MnO2 to create abundant oxygen vacancies and active sites for enhanced Oxygen Evolution Reaction

Nanoscale ◽  
2021 ◽  
Author(s):  
Jincan Jia ◽  
Lei Li ◽  
Xiao Lian ◽  
Mingzai Wu ◽  
Fangcai Zheng ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Precious Metal ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Mild Reduction ◽  
Huge Challenge ◽  
Co Doped

Efficient and non-precious metal-based catalysts (e.g., manganese-based oxides) for the oxygen evolution reaction (OER) still remains a huge challenge. It is rarely reported to create the oxygen vacancies of manganese-based...

Towards a Design of Active Oxygen Evolution Catalysts: Insights from Automated Density Functional Theory Calculations and Machine Learning

2019 ◽  
Author(s):  
Seoin Back ◽  
Kevin Tran ◽  
Zachary Ulissi
Keyword(s):  
Machine Learning ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Density Functional ◽  
Chemical Space ◽  
Density Functional Theory Calculations ◽  
Catalyst Design ◽  
Transition Metal Catalysts ◽  
Oxide Materials ◽  
Design Strategies

<div> <div> <div> <div><p>Developing active and stable oxygen evolution catalysts is a key to enabling various future energy technologies and the state-of-the-art catalyst is Ir-containing oxide materials. Understanding oxygen chemistry on oxide materials is significantly more complicated than studying transition metal catalysts for two reasons: the most stable surface coverage under reaction conditions is extremely important but difficult to understand without many detailed calculations, and there are many possible active sites and configurations on O* or OH* covered surfaces. We have developed an automated and high-throughput approach to solve this problem and predict OER overpotentials for arbitrary oxide surfaces. We demonstrate this for a number of previously-unstudied IrO2 and IrO3 polymorphs and their facets. We discovered that low index surfaces of IrO2 other than rutile (110) are more active than the most stable rutile (110), and we identified promising active sites of IrO2 and IrO3 that outperform rutile (110) by 0.2 V in theoretical overpotential. Based on findings from DFT calculations, we pro- vide catalyst design strategies to improve catalytic activity of Ir based catalysts and demonstrate a machine learning model capable of predicting surface coverages and site activity. This work highlights the importance of investigating unexplored chemical space to design promising catalysts.<br></p></div></div></div></div><div><div><div> </div> </div> </div>

scholarly journals Spinel of Nickel-Cobalt Oxide with Rod-Like Architecture as Electrocatalyst for Oxygen Evolution Reaction

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3918
Author(s):  
Anna Dymerska ◽  
Wojciech Kukułka ◽  
Marcin Biegun ◽  
Ewa Mijowska
Keyword(s):  
Cobalt Oxide ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Solvothermal Reaction ◽  
Step Method ◽  
One Pot ◽  
Widespread Application ◽  
Nickel Cobalt ◽  
Slow Kinetics ◽  
Nickel Cobalt Oxide

The renewable energy technologies require electrocatalysts for reactions, such as the oxygen and/or hydrogen evolution reaction (OER/HER). They are complex electrochemical reactions that take place through the direct transfer of electrons. However, mostly they have high over-potentials and slow kinetics, that is why they require electrocatalysts to lower the over-potential of the reactions and enhance the reaction rate. The commercially used catalysts (e.g., ruthenium nanoparticles—Ru, iridium nanoparticles—Ir, and their oxides: RuO2, IrO2, platinum—Pt) contain metals that have poor stability, and are not economically worthwhile for widespread application. Here, we propose the spinel structure of nickel-cobalt oxide (NiCo2O4) fabricated to serve as electrocatalyst for OER. These structures were obtained by a facile two-step method: (1) One-pot solvothermal reaction and subsequently (2) pyrolysis or carbonization, respectively. This material exhibits novel rod-like morphology formed by tiny spheres. The presence of transition metal particles such as Co and Ni due to their conductivity and electron configurations provides a great number of active sites, which brings superior electrochemical performance in oxygen evolution and good stability in long-term tests. Therefore, it is believed that we propose interesting low-cost material that can act as a super stable catalyst in OER.

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