scholarly journals Light-driven oxygen evolution from water oxidation: TiO2 engineering in the performance of the immobilised photocatalysts

2021 ◽  
Author(s):  
Maria J. Sampaio ◽  
Zhipeng Yu ◽  
Joana C. Lopes ◽  
Pedro B. Tavares ◽  
Cláudia G. Silva ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Water Oxidation ◽  
Photocatalytic Performance ◽  
Operation Mode ◽  
Sol Gel ◽  
Morphological Properties ◽  
Adsorption Sites ◽  
Oxygen Defects ◽  
Uv Led ◽  
Apparent Quantum Efficiency

Abstract Calcination treatments in the range of 500–900 ºC of TiO2 synthesised by the sol-gel resulted in materials with variable physicochemical (i.e., optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 ºC (TiO2-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO2-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 385 nm (UV-LED system) compared to the batch operation mode.

scholarly journals Light-driven oxygen evolution from water oxidation with immobilised TiO2 engineered for high performance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria J. Sampaio ◽  
Zhipeng Yu ◽  
Joana C. Lopes ◽  
Pedro B. Tavares ◽  
Cláudia G. Silva ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Water Oxidation ◽  
High Performance ◽  
Operation Mode ◽  
Sol Gel ◽  
Morphological Properties ◽  
Adsorption Sites ◽  
Oxygen Defects ◽  
Uv Led ◽  
Apparent Quantum Efficiency

AbstractCalcination treatments in the range of 500–900 °C of TiO2 synthesised by the sol–gel resulted in materials with variable physicochemical (i.e., optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 °C (TiO2-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO2-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 384 nm (UV-LED system) compared to the batch operation mode.

Controllable growth of graphdiyne layered nanosheets for high-performance water oxidation

2021 ◽  
Author(s):  
Shuya Zhao ◽  
Yurui Xue ◽  
Zhongqiang Wang ◽  
Zhiqiang Zheng ◽  
Xiaoyu Luan ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
High Performance ◽  
Low Cost ◽  
Highly Active ◽  
Controllable Growth

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

MOF-derived M-OOH with rich oxygen defects by in-situ electro-oxidation reconstitution for highly efficient oxygen evolution reaction

2021 ◽  
Author(s):  
Zhikai Shi ◽  
Zebin Yu ◽  
Ronghua Jiang ◽  
Jun Huang ◽  
Yanping Hou ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Energy Production ◽  
Low Cost ◽  
Highly Efficient ◽  
Oxygen Defects ◽  
Electro Oxidation

The oxygen evolution reaction (OER) is an important half-reaction in the field of energy production. However, how effectively, simply, and greenly to prepare low-cost OER electrocatalysts remains a problem. Herein,...

Bifunctional citrate-Ni0.9Co0.1(OH)x layer coated fluorine-doped hematite for simultaneous hole extraction and injection towards efficient photoelectrochemical water oxidation

Nanoscale ◽  
2021 ◽  
Author(s):  
Peng Wang ◽  
Feng Li ◽  
Xuefeng Long ◽  
Tong Wang ◽  
Huan Chai ◽  
...  
Keyword(s):  
Surface Modification ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Oxidation ◽  
Surface Oxygen ◽  
Co Catalyst ◽  
Photoelectrochemical Water Oxidation

Surface modification by loading a water oxidation co-catalyst (WOC) is generally considered to be an efficient means to optimize the sluggish surface oxygen evolution reaction (OER) of hematite photoanode for...

Rutile TiO2 single crystals delivering enhanced photocatalytic oxygen evolution performance

Nanoscale ◽  
2021 ◽  
Author(s):  
Bing Fu ◽  
Zhijiao Wu ◽  
Kai Guo ◽  
Lingyu Piao
Keyword(s):  
Catalytic Activity ◽  
Single Crystals ◽  
Oxygen Evolution ◽  
Water Oxidation ◽  
Charge Separation ◽  
High Surface ◽  
Rutile Tio2 ◽  
Highly Efficient ◽  
Photogenerated Charge Separation

Owing to their scientific and technological importance, the development of highly efficient photocatalytic water oxidation systems with rapid photogenerated charge separation and high surface catalytic activity has highly desirable for...

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 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

CoOx/UiO-66 and NiO/UiO-66 Heterostructures with UiO-66 Frameworks for Enhanced Oxygen Evolution Reactions

2021 ◽  
Author(s):  
Guangjin Zhang ◽  
Victor Charles ◽  
Yong Yang ◽  
Menglei Yuan ◽  
Jitao Zhang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Water Oxidation ◽  
Oxidation Reaction ◽  
Widespread Application ◽  
Coupled Process

Water oxidation reaction involves a four electron-proton coupled process that is kinetically sluggish and has hindered the widespread application of water-splitting technology. Metal-MOF-coupled heterostructures serve as good OER electrocatalysts due...

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