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 ◽  
...  

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.

2021 ◽  
Author(s):  
Maria J. Sampaio ◽  
Zhipeng Yu ◽  
Joana C. Lopes ◽  
Pedro B. Tavares ◽  
Cláudia G. Silva ◽  
...  

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.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sivalingam Ramesh ◽  
Jaehwan Kim ◽  
Joo-Hyung Kim

Recently, cellulose has much attention as an emerging renewable nanomaterial which holds promising properties having unique piezoelectricity, insulating, and biodegradable nature for various applications. Also, the modified properties of cellulose by appropriate chemical modifications in various functional groups with outstanding properties or significantly improved physical, chemical, biological, and electronic properties will widen the way for it to be utilized in different usages. Therefore, in this paper, cellulose-functionalized polyhedral oligomeric silsesquioxanes (POSS) based materials were considered an important class of high-performance hybrid nanocomposite materials. To functionalize the regenerated cellulose, amino functionalized POSS material was synthesized via sol-gel covalent crosslinking process in presence of amino coupling agent. In this reaction, tetraethoxsilane (TEOS) andγ-aminopropyltriethoxy silane (γ-APTES) as coupling agent for metal precursors were selected. The chemical structure of cellulose-amine functionalized bonding and covalent crosslinking hybrids was confirmed by FTIR and1H NMR spectral analysis. From the TEM results, well-dispersed hybrid cellulose-functionalized POSS-silica composites are observed. The resulting cellulose-POSS-silica hybrid nanocomposites materials provided significantly improved the optical transparency, and thermal and morphological properties to compare the cellulose-silica hybrid materials. Further, antimicrobial test against pathogenic bacteria was carried out.


Nanoscale ◽  
2020 ◽  
Author(s):  
Ning Xie ◽  
Dong-Dong Ma ◽  
Xintao Wu ◽  
Qi-Long Zhu

Constructing high-performance and cost-effective electrocatalysts for water oxidation, particularly for overall water splitting is extremely needed, whereas still challenging. Herein, based on an economical and facile one-step surface sulfurization strategy,...


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


2019 ◽  
Vol 7 (31) ◽  
pp. 18380-18387
Author(s):  
Byunghoon Kim ◽  
Ju Seong Kim ◽  
Hyunah Kim ◽  
Inchul Park ◽  
Won Mo Seong ◽  
...  

For the high-performance oxygen evolution reaction catalysts, we introduce amorphous cobalt–iron phyllosilicates (ACFPs), which explore the chemical space of phyllosilicate materials.


2020 ◽  
Vol 44 (4) ◽  
pp. 1455-1462 ◽  
Author(s):  
Jingyi Wang ◽  
Zhi Yang ◽  
Meilin Zhang ◽  
Yaqiong Gong

The as-obtained CoFe2O4@Ni3S2/NF can serve as an active and stable water oxidation catalyst under electrochemical reaction conditions.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1450
Author(s):  
Yanfang Liu ◽  
Yong Li ◽  
Qi Wu ◽  
Zhe Su ◽  
Bin Wang ◽  
...  

Electrolysis of water to produce hydrogen is crucial for developing sustainable clean energy and protecting the environment. However, because of the multi-electron transfer in the oxygen evolution reaction (OER) process, the kinetics of the reaction is seriously hindered. To address this issue, we designed and synthesized hollow CoP/FeP4 heterostructural nanorods interwoven by carbon nanotubes (CoP/FeP4@CNT) via a hydrothermal reaction and a phosphorization process. The CoP/FeP4@CNT hybrid catalyst delivers prominent OER electrochemical performances: it displays a substantially smaller Tafel slope of 48.0 mV dec−1 and a lower overpotential of 301 mV at 10 mA cm−2, compared with an RuO2 commercial catalyst; it also shows good stability over 20 h. The outstanding OER property is mainly attributed to the synergistic coupling between its unique CNT-interwoven hollow nanorod structure and the CoP/FeP4 heterojunction, which can not only guarantee high conductivity and rich active sites, but also greatly facilitate the electron transfer, ion diffusion, and O2 gas release and significantly enhance its electrocatalytic activity. This work offers a facile method to develop transition metal-based phosphide heterostructure electrocatalysts with a unique hierarchical nanostructure for high performance water oxidation.


2018 ◽  
Vol 6 (4) ◽  
pp. 1639-1647 ◽  
Author(s):  
Linjie Zhang ◽  
Taoqing Mi ◽  
Muhammad Asad Ziaee ◽  
Linfeng Liang ◽  
Ruihu Wang

Co3O4/CoMoO4 nanocages with an ultrafine crystallite size and high surface area derived from hollow H3PMo12O40@ZIF-67 hybrids exhibit high-performance for electrocatalytic oxygen evolution.


2018 ◽  
Vol 5 (7) ◽  
pp. 1570-1574 ◽  
Author(s):  
Qin Liu ◽  
Lisi Xie ◽  
Xifeng Shi ◽  
Gu Du ◽  
Abdullah M. Asiri ◽  
...  

An Ni-MOF nanosheet array on Ni foam (Ni-MOF/NF) acts as a high-performance and durable electrocatalyst for the oxygen evolution reaction in 1.0 M KOH, needing an overpotential of 320 mV to drive 100 mA cm−2.


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