Tunable surface modification of a hematite photoanode by a Co(salen)-based cocatalyst for boosting photoelectrochemical performance

2020 ◽  
Vol 10 (6) ◽  
pp. 1714-1723
Author(s):  
Ruiling Wang ◽  
Yasutaka Kuwahara ◽  
Kohsuke Mori ◽  
Yuyu Bu ◽  
Hiromi Yamashita

A water splitting photoanode composed of hematite (α-Fe2O3) nanorods modified with Co(salen) was proven to exhibit special photoelectrochemical oxygen evolution activity.

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 497 ◽  
Author(s):  
Lifei Xi ◽  
Kathrin Lange

Solar water splitting is a promising method for producing renewable fuels. Thermodynamically, the overall water splitting reaction is an uphill reaction involving a multiple electron transfer process. The oxygen evolution reaction (OER) has been identified as the bottleneck process. Hematite (α-Fe2O3) is one of the best photoanode material candidates due to its band gap properties and stability in aqueous solution. However, the reported efficiencies of hematite are notoriously lower than the theoretically predicted value mainly due to poor charge transfer and separation ability, short hole diffusion length as well as slow water oxidation kinetics. In this Review Article, several emerging surface modification strategies to reduce the oxygen evolution overpotential and thus to enhance the water oxidation reaction kinetics will be presented. These strategies include co-catalysts loading, photoabsorption enhancing (surface plasmonic metal and rare earth metal decoration), surface passivation layer deposition, surface chemical etching and surface doping. These methods are found to reduce charge recombination happening at surface trapping states, promote charge separation and diffusion, and accelerate water oxidation kinetics. The detailed surface modification methods, surface layer materials, the photoelectrochemical (PEC) performances including photocurrent and onset potential shift as well as the related proposed mechanisms will be reviewed.


2019 ◽  
Author(s):  
Jiajia Tao ◽  
Hong-Ping Ma ◽  
Kaiping Yuan ◽  
Yang Gu ◽  
Jianwei Lian ◽  
...  

<div>As a promising oxygen evolution reaction semiconductor, TiO2 has been extensively investigated for solar photoelectrochemical water splitting. Here, a highly efficient and stable strategy for rationally preparing GaON cocatalysts on TiO2 by atomic layer deposition is demonstrated, which we show significantly enhances the</div><div>photoelectrochemical performance compared to TiO2-based photoanodes. For TiO2@20 nm-GaON core-shell nanowires a photocurrent density up to 1.10 mA cm-2 (1.23 V vs RHE) under AM 1.5 G irradiation (100 mW cm-2) has been achieved, which is 14 times higher than that of TiO2 NWs. Furthermore, the oxygen vacancy formation on GaON as well as the band gap matching with TiO2 not only provides more active sites for water oxidation but also enhances light absorption to promote interfacial charge separation and migration. Density functional theory studies of model systems of GaON-modified TiO2 confirm the band gap reduction, high reducibility and ability to activate water. The highly efficient and stable systems of TiO2@GaON core-shell nanowires provide a deeper understanding and universal strategy for enhancing photoelectrochemical performance of photoanodes now available. </div>


2018 ◽  
Vol 11 (5) ◽  
pp. 1287-1298 ◽  
Author(s):  
Prashanth W. Menezes ◽  
Chakadola Panda ◽  
Stefan Loos ◽  
Florian Bunschei-Bruns ◽  
Carsten Walter ◽  
...  

The mechanistically distinct and synergistic role of phosphite anions in hydrogen evolution and nickel cations in oxygen evolution have been uncovered for active and durable overall water splitting catalysis in nickel phosphite.


2021 ◽  
Author(s):  
Zihao Liu ◽  
Shifeng Li ◽  
Fangfang Wang ◽  
Mingxia Li ◽  
Yonghong Ni

FeNi-layered double hydroxide (LDH) is thought to be an excellent electrocatalyst for oxygen evolution reaction (OER), but it always shows extremely poor electrocatalytic activity toward hydrogen evolution reaction (HER) in...


Nanoscale ◽  
2021 ◽  
Author(s):  
Peng Wang ◽  
Feng Li ◽  
Xuefeng Long ◽  
Tong Wang ◽  
Huan Chai ◽  
...  

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...


Author(s):  
Sisir Maity ◽  
Dheeraj Kumar Singh ◽  
Divya Bhutani ◽  
Suchitra Prasad ◽  
Umesh V. Waghmare ◽  
...  

Author(s):  
Ziqiang Wang ◽  
Peng Wang ◽  
Hugang Zhang ◽  
Wenjing Tian ◽  
You Xu ◽  
...  

The design of efficient bifunctional catalysts for hydrogen and oxygen evolution reactions is significant for electrochemical water splitting. Here, hierarchical IrTe nanotubes (NTs) with assembled nanosheets have been prepared through...


Author(s):  
Liang Zhao ◽  
Ding Chen ◽  
Shang Xu ◽  
Zhi Fang ◽  
Lin Wang ◽  
...  

Fast surface charge recombination and poor light capture capability are regarded as the two critical factors that hamper the photoelectrochemical (PEC) performance of photoanodes. In the present work, we employed...


Author(s):  
George Tsekouras ◽  
Richard Terrett ◽  
Zheyin Yu ◽  
Zhenxiang Cheng ◽  
Gerhard F. Swiegers ◽  
...  

Understanding of the operating mechanism of a ‘breathable’ water-splitting electrode, which extracts evolved gas without forming bubbles, is advanced.


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