scholarly journals PtAu Nanoparticles Supported by Reduced Graphene Oxide as a Highly Active Catalyst for Hydrogen Evolution

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Lazar Rakočević ◽  
Ivana Stojković Simatović ◽  
Aleksandar Maksić ◽  
Vladimir Rajić ◽  
Svetlana Štrbac ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Au Nanoparticles ◽  
Electrochemical Impedance ◽  
Pt Nanoparticles ◽  
Equilibrium Potential ◽  
High Catalytic Activity ◽  
Sem Images ◽  
Highly Active ◽  
Reduced Graphene ◽  
Constant Potential

PtAu nanoparticles spontaneously deposited on graphene support, PtAu/rGO, have shown remarkably high catalytic activity for hydrogen evolution reaction (HER) in sulfuric acid solution. SEM images of the PtAu/rGO electrode surface showed that Pt nanoparticles that are non-uniform in size occupy both the edges of previously deposited uniform Au nanoparticles and the edges of graphene support. XPS analysis showed that the atomic percentages of Au and Pt in PtAu/rGO were 0.6% and 0.3%, respectively. The atomic percentage of Au alone on previously prepared Au/rGO was 0.7%. Outstanding HER activity was achieved for the PtAu/rGO electrode, showing the initial potential close to the equilibrium potential for HER and a low Tafel slope of −38 mV/dec. This was confirmed by electrochemical impedance spectroscopy. The chronoamperometric measurement performed for 40 min for hydrogen evolution at a constant potential indicated good stability and durability of the PtAu/rGO electrode.

Highly active and stable electrocatalysts of FeS2–reduced graphene oxide for hydrogen evolution

2018 ◽  
Vol 54 (2) ◽  
pp. 1422-1433 ◽  
Author(s):  
Jibo Jiang ◽  
Liying Zhu ◽  
Haotian Chen ◽  
Yaoxin Sun ◽  
Wei Qian ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Highly Active ◽  
Reduced Graphene

Two-dimensional TaC nanosheets on a reduced graphene oxide hybrid as an efficient and stable electrocatalyst for water splitting

2016 ◽  
Vol 52 (57) ◽  
pp. 8810-8813 ◽  
Author(s):  
Chunyong He ◽  
Juzhou Tao
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Hydrogen Evolution Reaction ◽  
Two Dimensional ◽  
Highly Active ◽  
Reduced Graphene

A novel highly active and stable HER catalyst containing two-dimensional TaC nanosheets hybridized with reduced graphene oxide (2D TaC–RGO) was prepared as an efficient and stable hydrogen evolution reaction catalyst.

scholarly journals Hydrogen Evolution on Reduced Graphene Oxide-Supported PdAu Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 481
Author(s):  
Lazar Rakočević ◽  
Irina Srejić ◽  
Aleksandar Maksić ◽  
Jelena Golubović ◽  
Svetlana Štrbac
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Testing Time ◽  
Spontaneous Deposition ◽  
Reduced Graphene ◽  
Constant Potential ◽  
Pdau Nanoparticles

Hydrogen evolution reaction (HER) was investigated on reduced graphene oxide (rGO)-supported Au and PdAu nanoparticles in acid solution. The graphene spread over glassy carbon (rGO/GC) was used as a support for the spontaneous deposition of Au and Pd. The resulting Au/rGO and PdAu/rGO electrodes were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) techniques. Phase AFM images have shown that the edges of the rGO sheets were active sites for the deposition of both Au and Pd. XPS analysis revealed that the atomic percentages of both Au and PdAu nanoparticles were slightly higher than 1%. The activity of the PdAu/rGO electrode for the HER was remarkably high, with the overpotential close to zero. HER activity was stable over a 3 h testing time, with a low Tafel slope of approx. −46 mV/dec achieved after prolonged hydrogen evolution at a constant potential.

scholarly journals Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles as an Efficient Nanocomposite for Catalysis Applications in Cross-Coupling Reactions

2019 ◽  
Vol 14 (3) ◽  
pp. 490
Author(s):  
Hany A. Elazab ◽  
Tamer T. El-Idreesy
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Reduced Graphene Oxide ◽  
Cross Coupling ◽  
High Catalytic Activity ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Highly Active ◽  
Defect Sites ◽  
Reduced Graphene

This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h-1. Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction of palladium and in the presence of Gaphene oxide (GO) nanosheets using ethylene glycol as a solvent and also as a strong reducing agent. The highly active and recyclable catalyst has so many advantages including the use of mild reaction conditions, short reaction times in an environmentally benign solvent system. Moreover, the prepared catalyst could be recycled for up to five times with nearly the same high catalytic activity. Furthermore, the high catalytic activity and recyclability of the prepared catalyst are due to the strong catalyst-support interaction. The defect sites in the reduced Graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd/PVP nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease in the catalytic activity. Copyright © 2019 BCREC Group. All rights reserved 

scholarly journals rGO Sheets / ZnFe2O4 Nanocomposities as an Efficient Electro Catalyst Material for I3- / I- Reaction for High Performance DSSCs

2021 ◽  
Author(s):  
Anto feradrick Samson V ◽  
Bharathi Bernadsha S ◽  
Albin John P Paul Winston ◽  
Divya D ◽  
James Abraham ◽  
...  
Keyword(s):  
High Performance ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Dye Sensitized Solar Cells ◽  
X Ray Diffraction ◽  
Tafel Polarization ◽  
Highly Active ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Sensitized Solar Cells

Abstract In this paper, Reduced Graphene Oxide (rGO) / ZnFe2O4 (rZnF) nanocomposite is synthesized by a simple hydrothermal method and employed as a counter electrode (CE) material for tri-iodide redox reactions in Dye sensitized solar cells (DSSC) to replace the traditional high cost platinum (Pt) CE. X-ray diffraction analysis (XRD) and High resolution Transmission electron microscopy (HR-TEM), clearly indicated the formation of rZnF nanocomposite and also amorphous rGO sheets were smoothly distributed on the surface of ZnFe2O4 (ZnF) nanostructure. The rZnF-50 CE shows excellent electro catalytic activity toward I3− reduction, which has simultaneously been confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. A DSSC developed by rZnF-50 CE (η = 8.71%) obtained quite higher than the Pt (η = 8.53%) based CE under the same condition. The superior performances of rZnF-50 CE due to addition of graphene in to Spinel (ZnF) nanostructure results in creation of highly active electrochemical sites, fast electron transport linkage between CE and electrolyte. Thus it’s a promising low cost CE material for DSSCs.

scholarly journals Molybdenum Disulfide Nanosheets Decorated with Platinum Nanoparticle as a High Active Electrocatalyst in Hydrogen Evolution Reaction

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Mina Razavi ◽  
M. Sookhakian ◽  
Boon Tong Goh ◽  
Hadariah Bahron ◽  
Eyas Mahmoud ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Acidic Medium ◽  
High Performance ◽  
Hydrogen Adsorption ◽  
Electrochemical Impedance ◽  
Pt Nanoparticles ◽  
Platinum Nanoparticle ◽  
Molybdenum Disulfide Nanosheets

AbstractElectrochemical hydrogen evolution reaction (HER) refers to the process of generating hydrogen by splitting water molecules with applied external voltage on the active catalysts. HER reaction in the acidic medium can be studied by different mechanisms such as Volmer reaction (adsorption), Heyrovsky reaction (electrochemical desorption) or Tafel reaction (recombination). In this paper, facile hydrothermal methods are utilized to synthesis a high-performance metal-inorganic composite electrocatalyst, consisting of platinum nanoparticles (Pt) and molybdenum disulfide nanosheets (MoS2) with different platinum loading. The as-synthesized composite is further used as an electrocatalyst for HER. The as-synthesized Pt/Mo-90-modified glassy carbon electrode shows the best electrocatalytic performance than pure MoS2 nanosheets. It exhibits Pt-like performance with the lowest Tafel slope of 41 mV dec−1 and superior electrocatalytic stability in an acidic medium. According to this, the HER mechanism is related to the Volmer-Heyrovsky mechanism, where hydrogen adsorption and desorption occur in the two-step process. According to electrochemical impedance spectroscopy analysis, the presence of Pt nanoparticles enhanced the HER performance of the MoS2 nanosheets because of the increased number of charge carriers transport.

Facet-controlled hollow Rh2S3 hexagonal nanoprisms as highly active and structurally robust catalysts toward hydrogen evolution reaction

2016 ◽  
Vol 9 (3) ◽  
pp. 850-856 ◽  
Author(s):  
Donghwan Yoon ◽  
Bora Seo ◽  
Jaeyoung Lee ◽  
Kyoung Sik Nam ◽  
Byeongyoon Kim ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Core Shell ◽  
High Catalytic Activity ◽  
Highly Active ◽  
One Step ◽  
Very High ◽  
Excellent Stability

Hollow Rh2S3 hexagonal nanoprisms, prepared by one-step formation of core–shell nanoprisms followed by the etching of a core, exhibit very high catalytic activity and excellent stability toward hydrogen evolution reaction.

scholarly journals Boosting pH-Universal Hydrogen Evolution of FeP/CC by Anchoring Trace Platinum

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Chuancang Zhou ◽  
Feipeng Zhang ◽  
Hongyu Wu
Keyword(s):  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Pt Nanoparticles ◽  
Interface Energy ◽  
Catalytic Performance ◽  
Carbon Cloth ◽  
Electro Deposition ◽  
X Ray ◽  
Transition Metal Phosphides

To improve the electrocatalytic properties for hydrogen evolution reactions, strategies need to be adopted, such as increasing specific surface area and active site, as well as decreasing interface energy. Herein, we report the preparation of FeP on carbon cloth using a two-step process of hydrothermal and phosphating. Otherwise, to utilize the excellent catalytic performance of Pt and decrease consumption of Pt, the hyperdispersed Pt nanoparticles for the sake of modifying transition-metal phosphides film were designed and fabricated. Finally, 3D FeP-Pt/CC was successfully prepared by means of electro-deposition using three electrodes. The crystalline structure, surface morphology and elemental composition of the synthesized samples have been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS). The XRD results show that the as-prepared products are of orthorhombic FeP structure, and EDS results indicate that there exist Pt elements in 3D FeP-Pt/CC. The electrocatalytic performances were evaluated by, such as linear scan voltammetry, tafel plots and electrochemical impedance spectroscopy on electrochemical workstations. These results show that the FeP-Pt/CC exhibit a current density of 10 mA·cm−2 at an over-potential of 58 mV for HER in 0.5 M H2SO4, which is very close to the values of 20%Pt/C which was previously reported. FeP-Pt/CC has excellent durability.

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