Constructing Chemical Interaction between Hematite and Carbon Nanosheets with Single Active Sites for Efficient Photo‐Electrochemical Water Oxidation

Small Methods ◽  
2020 ◽  
Vol 4 (12) ◽  
pp. 2000577
Author(s):  
Gaoliang Yang ◽  
Yunxiang Li ◽  
Huiwen Lin ◽  
Xiaohui Ren ◽  
Davin Philo ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Active Sites ◽  
Chemical Interaction ◽  
Carbon Nanosheets

Oriental and robust anchoring of Fe via anodic interfacial coordination assembly on ultrathin Co hydroxides for efficient water oxidation

Nanoscale ◽  
2021 ◽  
Author(s):  
Ya-Nan Zhou ◽  
Ruo-Yao Fan ◽  
Yu-Ning Cao ◽  
Hui-Ying Wang ◽  
Bin Dong ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Active Sites

The oriental distribution and strong conjunction of Fe active sites in multiple metals hydroxides are very crucial to modulate the activity and stability for efficient oxygen evolution reaction (OER). Whereas,...

scholarly journals Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

2012 ◽  
Vol 9 (75) ◽  
pp. 2383-2395 ◽  
Author(s):  
Mohammad Mahdi Najafpour ◽  
Fahimeh Rahimi ◽  
Eva-Mari Aro ◽  
Choon-Hwan Lee ◽  
Suleyman I. Allakhverdiev
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Water Oxidation ◽  
Active Sites ◽  
Manganese Oxides ◽  
Metal Compounds ◽  
Functional Models ◽  
Current Densities ◽  
Conversion Efficiencies ◽  
Manganese Compounds

There has been a tremendous surge in research on the synthesis of various metal compounds aimed at simulating the water-oxidizing complex (WOC) of photosystem II (PSII). This is crucial because the water oxidation half reaction is overwhelmingly rate-limiting and needs high over-voltage (approx. 1 V), which results in low conversion efficiencies when working at current densities required for hydrogen production via water splitting. Particular attention has been given to the manganese compounds not only because manganese has been used by nature to oxidize water but also because manganese is cheap and environmentally friendly. The manganese–calcium cluster in PSII has a dimension of about approximately 0.5 nm. Thus, nano-sized manganese compounds might be good structural and functional models for the cluster. As in the nanometre-size of the synthetic models, most of the active sites are at the surface, these compounds could be more efficient catalysts than micrometre (or bigger) particles. In this paper, we focus on nano-sized manganese oxides as functional and structural models of the WOC of PSII for hydrogen production via water splitting and review nano-sized manganese oxides used in water oxidation by some research groups.

scholarly journals Morphological and Elemental Investigations on Co–Fe–B–O Thin Films Deposited by Pulsed Laser Deposition for Alkaline Water Oxidation: Charge Exchange Efficiency as the Prevailing Factor in Comparison with the Adsorption Process

2021 ◽  
Author(s):  
Y. Popat ◽  
M. Orlandi ◽  
S. Gupta ◽  
N. Bazzanella ◽  
S. Pillai ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Water Oxidation ◽  
Active Sites ◽  
High Surface ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Active Species ◽  
Laser Deposition ◽  
Core Shell ◽  
Adsorption Sites

Abstract Mixed transition-metals oxide electrocatalysts have shown huge potential for electrochemical water oxidation due to their earth abundance, low cost and excellent electrocatalytic activity. Here we present Co–Fe–B–O coatings as oxygen evolution catalyst synthesized by Pulsed Laser Deposition (PLD) which provided flexibility to investigate the effect of morphology and structural transformation on the catalytic activity. As an unusual behaviour, nanomorphology of 3D-urchin-like particles assembled with crystallized CoFe2O4 nanowires, acquiring high surface area, displayed inferior performance as compared to core–shell particles with partially crystalline shell containing boron. The best electrochemical activity towards water oxidation in alkaline medium with an overpotential of 315 mV at 10 mA/cm2 along with a Tafel slope of 31.5 mV/dec was recorded with core–shell particle morphology. Systematic comparison with control samples highlighted the role of all the elements, with Co being the active element, boron prevents the complete oxidation of Co to form Co3+ active species (CoOOH), while Fe assists in reducing Co3+ to Co2+ so that these species are regenerated in the successive cycles. Thorough observation of results also indicates that the activity of the active sites play a dominating role in determining the performance of the electrocatalyst over the number of adsorption sites. The synthesized Co–Fe–B–O coatings displayed good stability and recyclability thereby showcasing potential for industrial applications. Graphic Abstract

Preparation of Fe/N co-doped hierarchical porous carbon nanosheets derived from chitosan nanofibers for high-performance supercapacitors

2021 ◽  
pp. 1-16
Author(s):  
Yaqi Yang ◽  
Ziqiang Shao ◽  
Feijun Wang
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Active Sites ◽  
Transport Pathway ◽  
Carbon Nanosheets ◽  
Hierarchical Porous

Abstract Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.

Capturing the active sites of multimetallic (oxy)hydroxides for the oxygen evolution reaction

2020 ◽  
Vol 13 (11) ◽  
pp. 4225-4237
Author(s):  
Xin Bo ◽  
Rosalie K Hocking ◽  
Si Zhou ◽  
Yibing Li ◽  
Xianjue Chen ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Active Sites ◽  
Alkaline Water ◽  
Catalytic Active Sites

The catalytic active sites of NiFe and NiFeCr (oxy)hydroxides are revealed by operando spectroscopic techonologies for alkaline water oxidation.

scholarly journals Short-range amorphous carbon nanosheets for oxygen reduction electrocatalysis

2020 ◽  
Vol 2 (12) ◽  
pp. 5769-5776
Author(s):  
Qingyu Li ◽  
Dingding Kong ◽  
Xinyi Zhao ◽  
Yezheng Cai ◽  
Zhaoling Ma ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction ◽  
Amorphous Carbon ◽  
Active Sites ◽  
Short Range ◽  
Widespread Application ◽  
Carbon Nanosheets

Selectively creating active sites that can work well in different media as much as possible remains an open challenge for the widespread application of sustainable metal air batteries and fuel cells.

Sign in / Sign up

Export Citation Format

Share Document