scholarly journals Aromaticity Driven Electrocatalytic Water Oxidation by a Phosphorus-Nitrogen PN3-Pincer Cobalt Complex

2019 ◽  
Author(s):  
Pradip K. Das ◽  
Sarmistha Bhunia ◽  
Priyanka Chakraborty ◽  
Atanu Rana ◽  
Abhishek Dey ◽  
...  
Keyword(s):  
Water Oxidation ◽  
High Efficiency ◽  
Cobalt Complex ◽  
Potential Jump ◽  
Onset Potential ◽  
New Strategy ◽  
Earth Abundant ◽  
High Valent ◽  
Lower Overpotential ◽  
Cobalt Species

Water oxidation is the primary step in both natural and artificial photosynthesis to convert solar energy in into chemical fuels. Herein, we report the first cobalt-based pincer catalyst for electrolytic water oxidation at neutral pH with high efficiency under electrochemical conditions. Most importantly, ligand (pseudo)aromaticity is identified to play an important role in the electrocatalysis. A significant potential jump (~300 mV) was achieved towards a lower positive value when the aromatized cobalt complex was transformed to a (pseudo)dearomatized cobalt species. This complex catalyzes the water oxidation in its high valent oxidation state at a much lower overpotential (~ 340 mV vs. NHE) based on the onset potential (0.5 mA/cm<sup>2</sup>) of catalysis at pH 10.5, outperforming all the other literature systems. These observations may provide a new strategy for the design of earth-abundant transition metal-based water oxidation catalysts.

scholarly journals Aromaticity Driven Electrocatalytic Water Oxidation by a Phosphorus-Nitrogen PN3-Pincer Cobalt Complex

2019 ◽  
Author(s):  
Pradip K. Das ◽  
Sarmistha Bhunia ◽  
Priyanka Chakraborty ◽  
Atanu Rana ◽  
Abhishek Dey ◽  
...  
Keyword(s):  
Water Oxidation ◽  
High Efficiency ◽  
Cobalt Complex ◽  
Potential Jump ◽  
Onset Potential ◽  
New Strategy ◽  
Earth Abundant ◽  
High Valent ◽  
Lower Overpotential ◽  
Cobalt Species

Water oxidation is the primary step in both natural and artificial photosynthesis to convert solar energy in into chemical fuels. Herein, we report the first cobalt-based pincer catalyst for electrolytic water oxidation at neutral pH with high efficiency under electrochemical conditions. Most importantly, ligand (pseudo)aromaticity is identified to play an important role in the electrocatalysis. A significant potential jump (~300 mV) was achieved towards a lower positive value when the aromatized cobalt complex was transformed to a (pseudo)dearomatized cobalt species. This complex catalyzes the water oxidation in its high valent oxidation state at a much lower overpotential (~ 340 mV vs. NHE) based on the onset potential (0.5 mA/cm<sup>2</sup>) of catalysis at pH 10.5, outperforming all the other literature systems. These observations may provide a new strategy for the design of earth-abundant transition metal-based water oxidation catalysts.

Magnetic Multifunctional Nanostructures as High-efficiency Catalysts for Oxygen Evolution Reactions

MRS Advances ◽  
2016 ◽  
Vol 1 (34) ◽  
pp. 2401-2407 ◽  
Author(s):  
Umanga De Silva ◽  
W. P. R. Liyanage ◽  
Manashi Nath
Keyword(s):  
Oxygen Evolution ◽  
Water Oxidation ◽  
High Efficiency ◽  
Clean Energy ◽  
Elemental Selenium ◽  
Ferromagnetic Behavior ◽  
High Electron ◽  
Metallic Component ◽  
Onset Potential ◽  
Multifunctional Nanostructures

AbstractThe search for high-efficiency and environmentally benign water splitting catalysts has been on the rise since this process is a source of renewable, clean energy. However the process is inherently slow, especially for the production of O2 from H2O (water oxidation) due to the high electron count and energy intensive bond formation of the reaction. Hence the search for novel catalysts for oxygen evolution reactions (OER) has led researchers to focus on various families of compounds including oxides and recently selenides. Multifunctional nanostructures containing the semiconductor electrocatalyst grafted onto an optically active metallic component might boost the catalytic activity even further due to efficient charge injection. Magnetically active catalysts will also be lucrative since that might induce better adhesion of the oxygenated species at the catalytically active site. In this report we introduce multifunctional, magnetic Au3Pd–CoSe nanostructures as high-efficiency OER electrocatalysts. These multifunctional nanostructures were synthesized by a chemical vapor deposition (CVD) reaction with cobalt acetylacetonate and elemental selenium on Au-Pd sputter coated silica substrate at 800°C. The morphology of these multifunctional nanostructures were mostly bifunctional Janus-like nanoparticles as seen through scanning and transmission electron microscopy. They also showed soft ferromagnetic behavior. These bifunctional nanoparticles were coated on the anodes of a water oxidation cell and it was observed that these nanoparticles showed a higher OER activity with lower onset potential for O2 evolution as compared to the conventional oxide-based OER electrocatalysts.

Electrocatalytic water oxidation by a molecular cobalt complex through a high valent cobalt oxo intermediate

2016 ◽  
Vol 52 (79) ◽  
pp. 11787-11790 ◽  
Author(s):  
Debasree Das ◽  
Santanu Pattanayak ◽  
Kundan K. Singh ◽  
Bikash Garai ◽  
Sayam Sen Gupta
Keyword(s):  
Water Oxidation ◽  
Cobalt Complex ◽  
High Valent

Biuret-modified tetraamidomacrocyclic cobalt complex [CoIII-bTAML]− is shown to catalyze electrochemical water oxidation at basic pH leading to the formation of O2.

Hydrogenated hematite nanostructures for high-efficiency solar water oxidation

RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 92206-92212 ◽  
Author(s):  
Litao Zhou ◽  
Xiaolin Lv ◽  
Yuting Nie ◽  
Jiujun Deng ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Oxygen Vacancies ◽  
High Efficiency ◽  
Onset Potential ◽  
Solar Water ◽  
Solar Water Oxidation

Hematite with oxygen vacancies can lower the onset potential and achieve a high photocurrent of 2.00 mA cm−2 at 1.0 VRHE.

scholarly journals Improving the onset potential and Tafel slope determination of earth-abundant water oxidation electrocatalysts

2021 ◽  
pp. 138613
Author(s):  
Roger Sanchis-Gual ◽  
Alvaro Seijas-Da Silva ◽  
Marc Coronado-Puchau ◽  
Toribio F. Otero ◽  
Gonzalo Abellán ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Tafel Slope ◽  
Onset Potential ◽  
Earth Abundant

scholarly journals Rapid solvent-evaporation strategy for three-dimensional cobalt-based complex hierarchical architectures as catalysts for water oxidation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hong Jiang ◽  
Hao Zhang ◽  
Qiaoling Kang ◽  
Haifeng Ma ◽  
Yinlin Tong ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Cobalt Complex ◽  
3D Structure ◽  
Three Dimensional ◽  
Solvent Evaporation ◽  
Electrochemical Performances ◽  
Polarization Current ◽  
Simple Method ◽  
Onset Potential ◽  
Hierarchical Architectures

Abstract It is a challenging task to seek a highly-efficient electrocatalyst for oxygen evolution reaction (OER) of water splitting. Non-noble Co-based nanomaterials are considered as earth-abundant and effective catalysts to lower overpotential and increase polarization current density of OER. In this work, we reported, for the first time, a “rapid solvent-evaporation” strategy for the synthesis of three-dimensional (3D) cobalt complex hierarchical architectures constructed by two-dimensional (2D) nanosheets. The 3D structured cobalt complexes have excellent performances in catalyzing OER with lower onset potential, overpotential, Tafel slope and better stability than commercial IrO2. Superior electrochemical performances would be beneficial from the unique 3D structure. This extremely simple method for 3D Co complex with good OER activities makes the complex be promising commercial OER catalyst to replace earth-rare and expensive IrO2.

Electrochemical evidence for catalytic water oxidation mediated by a high-valent cobalt complex

2011 ◽  
Vol 47 (14) ◽  
pp. 4249 ◽  
Author(s):  
Derek J. Wasylenko ◽  
Chelladurai Ganesamoorthy ◽  
Javier Borau-Garcia ◽  
Curtis P. Berlinguette
Keyword(s):  
Water Oxidation ◽  
Cobalt Complex ◽  
High Valent

scholarly journals Photocorrosion-Resistant Sb2Se3 Photocathodes with Earth Abundant MoSx Hydrogen Evolution Catalyst

2017 ◽  
Author(s):  
David Tilley ◽  
Rajiv Ramanujam Prabhakar ◽  
Wilman Septina ◽  
Sebastian Siol ◽  
Thomas Moehl ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrogen Evolution ◽  
Large Scale ◽  
High Efficiency ◽  
Aqueous Media ◽  
Onset Potential ◽  
Protective Layers ◽  
Earth Abundant ◽  
Strong Candidate ◽  
Holding Back

<p>The poor stability of high efficiency photoabsorber materials in aqueous media is one factor holding back the realization of photoelectrochemical (PEC) water splitting for large scale, practical solar fuels generation. Here, we demonstrate that highly efficient thin film Sb<sub>2</sub>Se<sub>3</sub>–fabricated by a simple, low temperature selenization of electrodeposited Sb–is intrinsically stable towards photocorrosion in strongly acidic media (1 M H<sub>2</sub>SO<sub>4</sub>). Coupling with a photoelectrodeposited MoS<sub>x</sub> hydrogen evolution catalyst gives high photocurrents (5 mA cm<sup>-2</sup> at 0 V vs RHE) and high stability without protective layers (10 h with ~20% loss). A low temperature sulfurization of the Sb<sub>2</sub>Se<sub>3</sub>-MoS<sub>x</sub> stack dramatically improved the onset potential, resulting in high photocurrent densities up to 16 mA cm<sup>-2</sup> at 0 V vs RHE. The simplicity with which these photocathodes are fabricated, combined with the high photocurrents and stability, make Sb<sub>2</sub>Se<sub>3</sub> a strong candidate for scalable PEC cells.</p>

scholarly journals Photocorrosion-Resistant Sb2Se3 Photocathodes with Earth Abundant MoSx Hydrogen Evolution Catalyst

2017 ◽  
Author(s):  
David Tilley ◽  
Rajiv Ramanujam Prabhakar ◽  
Wilman Septina ◽  
Sebastian Siol ◽  
Thomas Moehl ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrogen Evolution ◽  
Large Scale ◽  
High Efficiency ◽  
Aqueous Media ◽  
Onset Potential ◽  
Protective Layers ◽  
Earth Abundant ◽  
Strong Candidate ◽  
Holding Back

<p>The poor stability of high efficiency photoabsorber materials in aqueous media is one factor holding back the realization of photoelectrochemical (PEC) water splitting for large scale, practical solar fuels generation. Here, we demonstrate that highly efficient thin film Sb<sub>2</sub>Se<sub>3</sub>–fabricated by a simple, low temperature selenization of electrodeposited Sb–is intrinsically stable towards photocorrosion in strongly acidic media (1 M H<sub>2</sub>SO<sub>4</sub>). Coupling with a photoelectrodeposited MoS<sub>x</sub> hydrogen evolution catalyst gives high photocurrents (5 mA cm<sup>-2</sup> at 0 V vs RHE) and high stability without protective layers (10 h with ~20% loss). A low temperature sulfurization of the Sb<sub>2</sub>Se<sub>3</sub>-MoS<sub>x</sub> stack dramatically improved the onset potential, resulting in high photocurrent densities up to 16 mA cm<sup>-2</sup> at 0 V vs RHE. The simplicity with which these photocathodes are fabricated, combined with the high photocurrents and stability, make Sb<sub>2</sub>Se<sub>3</sub> a strong candidate for scalable PEC cells.</p>

Sign in / Sign up

Export Citation Format

Share Document