Enhancing the electrocatalytic activity and stability of Prussian blue analogues by increasing their electroactive sites through the introduction of Au nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Roger Sanchis-Gual ◽  
Toribio F. Otero ◽  
Marc Coronado Puchau ◽  
Eugenio Coronado

Prussian blue analogues (PBAs) have been proven as excellent earth‐abundant electrocatalysts for the oxygen evolution reaction (OER) in acidic, neutral and alkaline media. Still, further improvements can be achieved by...

2021 ◽  
Author(s):  
Roger Sanchis-Gual ◽  
Toribio F. Otero ◽  
Marc Coronado-Puchau ◽  
Eugenio Coronado

Prussian blue analogues (PBAs) have shown to be useful as earth-abundant electrocatalysts for the Oxygen Evolution Reaction (OER) in acidic, neutral and alkaline media. Still, further improvements can be achieved by increasing their electrical conductivity. In this work, we have obtained and fully characterized a variety of monodisperse core@shell hybrid nanoparticles of Au@PBA (PBA of NiIIFeII and CoIIFeII) with different shell sizes. Their electrocatalytical activity is evaluated by studying the OER, which is compared to the pristine PBA and other Au-PBA heterostructures. It was observed that the introduction in a core@shell of 5-10 % of Au in weight leads to an increment in the electroactive mass able to be reduced or oxidized and thus, to a higher number of sites capable to take part in the OER. This larger amount of electroactive sites leads to a significant decrease in the onset potential (a reduction of the onset potential up to 100 mV and an increase up to 420 % of the current density recorded at an overpotential of 350 mV), while the Tafel slope remains unchanged, suggesting that Au reduces the limiting potential of the catalyst with no variation in the reaction kinetics. These effects are not experimented in the other Au-PBA nanostructures mainly due to the lower contact between both compounds and the oxidation of Au. Hence, an Au core activates the PBA shell and increases the conductivity of the resulting hybrid while the PBA shell prevents Au oxidation. These improvements come from the strong synergistic effect existing in the core@shell structure and evidence the importance of the chemical design for preparing PBA-based nanostructures displaying better electrocatalytic performances and higher electrochemical stabilities.


2021 ◽  
Author(s):  
Roger Sanchis-Gual ◽  
Toribio F. Otero ◽  
Marc Coronado-Puchau ◽  
Eugenio Coronado

Prussian blue analogues (PBAs) have shown to be useful as earth-abundant electrocatalysts for the Oxygen Evolution Reaction (OER) in acidic, neutral and alkaline media. Still, further improvements can be achieved by increasing their electrical conductivity. In this work, we have obtained and fully characterized a variety of monodisperse core@shell hybrid nanoparticles of Au@PBA (PBA of NiIIFeII and CoIIFeII) with different shell sizes. Their electrocatalytical activity is evaluated by studying the OER, which is compared to the pristine PBA and other Au-PBA heterostructures. It was observed that the introduction in a core@shell of 5-10 % of Au in weight leads to an increment in the electroactive mass able to be reduced or oxidized and thus, to a higher number of sites capable to take part in the OER. This larger amount of electroactive sites leads to a significant decrease in the onset potential (a reduction of the onset potential up to 100 mV and an increase up to 420 % of the current density recorded at an overpotential of 350 mV), while the Tafel slope remains unchanged, suggesting that Au reduces the limiting potential of the catalyst with no variation in the reaction kinetics. These effects are not experimented in the other Au-PBA nanostructures mainly due to the lower contact between both compounds and the oxidation of Au. Hence, an Au core activates the PBA shell and increases the conductivity of the resulting hybrid while the PBA shell prevents Au oxidation. These improvements come from the strong synergistic effect existing in the core@shell structure and evidence the importance of the chemical design for preparing PBA-based nanostructures displaying better electrocatalytic performances and higher electrochemical stabilities.


2019 ◽  
Vol 27 (03) ◽  
pp. 1950122
Author(s):  
NILOOFAR TAHERIAN ◽  
SOHRAB SANJABI

This study carried out to examine electrocatalytic activity of Ni–Mn–Sn alloy foams for oxygen evolution reaction (OER) in alkaline media. As the first step, Ni–Mn–Sn alloy foams were prepared of sulfate bath on copper substrate. Next, after optimization of electrodeposition condition by cyclic voltammetry (CV) test, foams were electrodeposited at different current densities 100, 120, 140 and 180[Formula: see text]mA[Formula: see text]⋅[Formula: see text]cm[Formula: see text]. Then, they were characterized by field emission scanning electron microscopy (FE-SEM) along with energy disperse x-ray spectroscopy (EDS) to investigate surface morphologies and chemical compositions. According to FE-SEM results, it was revealed that formation of foam like structures were due to the presence of dynamic hydrogen bubbles template (DHBT). To survey their structure, grazing incidence X-ray diffractometer (GIXRD) analysis was performed. The resulted diffraction pattern determined not only FCC nickel structure of foams, but also mixed phases composed. Following this, Ni–Mn–Sn alloy foams were placed in 0.1 M KOH and related CV tests were applied to measure their electrocatalytic activity for OER. This study demonstrated good electrocatalytic activity for Ni–Mn–Sn alloy foams by showing favorable oxygen evolution overpotenitals and Tafel slopes.


2021 ◽  
Vol 393 ◽  
pp. 390-398
Author(s):  
Ji Hoon Lee ◽  
Shyam Kattel ◽  
Yan Wang ◽  
Brian M. Tackett ◽  
Zhenhua Xie ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (72) ◽  
pp. 42387-42394 ◽  
Author(s):  
Abdul Qayoom Mugheri ◽  
Aneela Tahira ◽  
Umair Aftab ◽  
Adeel Liaquat Bhatti ◽  
Nusrat Naeem Memon ◽  
...  

In this study, a simple approach was used to produce nonprecious, earth abundant, stable and environmentally friendly NiCo2O4/CuO composites for the oxygen evolution reaction (OER) in alkaline media.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2304 ◽  
Author(s):  
Dongni Zhao ◽  
Yuezhen Lu ◽  
Dongge Ma

The importance of advanced energy-conversion devices such as water electrolysis has manifested dramatically over the past few decades because it is the current mainstay for the generation of green energy. Anodic oxygen evolution reaction (OER) in water splitting is one of the biggest obstacles because of its extremely high kinetic barrier. Conventional OER catalysts are mainly noble-metal oxides represented by IrO2 and RuO2, but these compounds tend to have poor sustainability. The attention on Prussian blue (PB) and its analogs (PBA) in the field of energy conversion systems was concentrated on their open-framework structure, as well as its varied composition comprised of Earth-abundant elements. The unique electronic structure of PBA enables its promising catalytic potential, and it can also be converted into many other talented compounds or structures as a precursor. This undoubtedly provides a new approach for the design of green OER catalysts. This article reviews the recent progress of the application of PBA and its derivatives in OER based on in-depth studies of characterization techniques. The structural design, synthetic strategy, and enhanced electrochemical properties are summarized to provide an outlook for its application in the field of OER. Moreover, due to the similarity of the reaction process of photo-driven electrolysis of water and the former one, the application of PBA in photoelectrolysis is also discussed.


Author(s):  
Chen Ye ◽  
Longcheng Zhang ◽  
Luchao Yue ◽  
Biao Deng ◽  
Yang Cao ◽  
...  

The development of efficient electrocatalysts from earth-abundant elements for the oxygen evolution reaction (OER) is highly desired. Here, we report the electrodeposition of NiCo layered double hydroxide nanosheet array on...


2018 ◽  
Vol 5 (8) ◽  
pp. 1962-1966 ◽  
Author(s):  
Fanhao Kong ◽  
Kunfeng Chen ◽  
Shuyan Song ◽  
Dongfeng Xue

Architectures of CoFe@N-doped carbon/wrinkled rGO sheets are synthesizedviathe one-step annealing of Prussian blue analogues and GO sheet composites. The optimized structure exhibits a low overpotential of 278 mV to drive 10 mA cm−2and has a durable stability.


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