Unraveling the Hydrogen Evolution Reaction Active Sites in N‐Functionalized Interconnected Graphene Quantum Dots

Kundu, Sumana; Malik, Bibhudatta; Pattanayak, Deepak K.; Ragupathy, P.; Pillai, Vijayamohanan K.

doi:10.1002/slct.201700631

Cited by 9 publications

(6 citation statements)

References 50 publications

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“…Electrocatalytic hydrogen evolution performance. (a, b) LSV polarization curves of NGODs-AuNPs in comparison with NGQDs-AuNPs, pristine NGODs, NGQDs, AuNPs, glassy carbon (GC) electrode, and carbon powder in a 0.5 M H 2 SO 4 aqueous solution, and their corresponding (c) Tafel slopes, (d) mass activity (A/g) and overpotential (mV)@10 mV/cm 2 values, and (e) comparison of HER activity (overpotential (V vs RHE) vs current density @10 mA.cm –2 ) with various carbon and metal@carbon-based catalysts. ,− …”

Section: Resultsmentioning

confidence: 99%

Integration of Nitrogen-Doped Graphene Oxide Dots with Au Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution

Bogireddy

Hachimi

Muñiz

et al. 2021

ACS Appl. Nano Mater.

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Platinum (Pt)-free catalysts play a significant role in renewable energy and water purification. However, their design and synthesis are challenging as they need to satisfy the increasing demands, low cost, and enhanced catalytic performance with high efficiency to effectively replace Pt-based materials. This work reports the enhanced catalytic efficiencies of gold nanoparticles (AuNPs) in the presence of nitrogen-doped graphene oxide dots (NGODs) for hydrogen evolution in a 0.5 M H 2 SO 4 electrolyte with a Tafel slope of 87 mV dec −1 and an overpotential of 145 mV vs RHE at 10 mA cm −2 . In addition, the hybrid structure reveals the complete removal of organic pollutants with higher catalytic efficiencies as compared to Pt, Pd, and Rh hybrid catalysts. DFT calculations demonstrate that the observed high catalytic activity originates from the oxygen-containing groups present on NGODs and AuNPs. This study may open new avenues for developing scalable and economically viable hybrid systems.

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Section: Resultsmentioning

confidence: 99%

Integration of Nitrogen-Doped Graphene Oxide Dots with Au Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution

Bogireddy

Hachimi

Muñiz

et al. 2021

ACS Appl. Nano Mater.

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“…The electrocatalytic performance of nitrogen functionalized inter-connected GQDs (c-GQDs) was reported by Kundu et al [73] GQDs were treated with hydrazine hydrate in acidic conditions so as to synthesize 3D c-GQDs. 0D GQDs are inter-connected through a form of hydrazine bonding, as shown in Figure 6a.…”

Section: Graphene Quantum Dots/graphene Quantum Sheetsmentioning

confidence: 99%

Low Dimensional Carbon-Based Catalysts for Efficient Photocatalytic and Photo/Electrochemical Water Splitting Reactions

et al. 2019

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A universal increase in energy consumption and the dependency on fossil fuels have resulted in increasing severity of global warming, thus necessitating the search of new and environment-friendly energy sources. Hydrogen is as one of the energy sources that can resolve the abovementioned problems. Water splitting promotes ecofriendly hydrogen production without the formation of any greenhouse gas. The most common process for hydrogen production is electrolysis, wherein water molecules are separated into hydrogen and oxygen through electrochemical reactions. Solar-energy-induced chemical reactions, including photocatalysis and photoelectrochemistry, have gained considerable attention because of the simplicity of their procedures and use of solar radiation as the energy source. To improve performance of water splitting reactions, the use of catalysts has been widely investigated. For example, the novel-metal catalysts possessing extremely high catalytic properties for various reactions have been considered. However, due to the rarity and high costs of the novel-metal materials, the catalysts were considered unsuitable for universal use. Although other transition-metal-based materials have also been investigated, carbon-based materials, which are obtained from one of the most common elements on Earth, have potential as low-cost, nontoxic, high-performance catalysts for both photo and electrochemical reactions. Because abundancy, simplicity of synthesis routes, and excellent performance are the important factors for catalysts, easy optimization and many variations are possible in carbon-materials, making them more attractive. In particular, low-dimensional carbon materials, such as graphene and graphitic carbon nitride, exhibit excellent performance because of their unique electrical, mechanical, and catalytic properties. In this mini-review, we will discuss the performance of low-dimensional carbon-based materials for water splitting reactions.

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“…Herein, we have used a synthetic route which has been carried out in acidic medium to integrate all the distinct GQDs by interconnection to form a “3‐D” GQDs massive structure (C‐GQDs). The detail characterizations and synthetic route could be found in our previous report . Interestingly, apart from the interconnection, the N‐surface functionalizations at pyridinic and pyridine N‐oxide sites of GQDs have also been observed (XPS analysis before and after OER).…”

Section: Figurementioning

confidence: 99%

“…Although, the role of pyridinic N towards OER has been reported earlier, but according to best of our knowledge the role of pyridine N‐oxide sites for its OER activity is not so familiar. However, the pyridine N‐oxide acts both as electrophilic as well as nucleophilic site . In this case it is acting as a nucleophilic site and the resonating structure has been shown in the schematic with its charge distribution unveiling the catalytic active site (*).…”

Section: Figurementioning

confidence: 99%

Role of Specific N-Containing Active Sites in Interconnected Graphene Quantum Dots for the Enhanced Electrocatalytic Activity towards Oxygen Evolution Reaction

et al. 2017

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Electrochemical water oxidation is a dynamic and basal approach for several energy conversion technologies such as solar fuels and metal–air batteries. Herein, we report a novel ‘nitrogen’ (N) enriched interconnected graphene quantum dots (C‐GQDs) as efficient oxygen evolution electrocatalyst, a potential candidate to replace the noble metal OER electrocatalysts. Interestingly, C‐GQDs deliver a current density of 10 mAcm‐2 at 350 mV, a small Tafel slope of 55 mV/dec and outstanding durability which is much superior to the state‐of‐the‐art precious RuO2. More precisely, the unexpected behaviour of graphene quantum dots towards oxygen evolution reaction (OER) is attributed to the interconnection through N‐rich framework (25 %) among the discrete particles. Predominantly, in the pyridine N‐oxide, N acts as nucleophilic site and pyridinic N develops p‐ type doping, responsible for enhanced the OER electrocatalytic activity. The co‐existence of both pyridinic N and pyridine N‐oxide N induces charge redistribution through π‐π delocalization to reduce the *OOH thermodynamic energy barrier. We hope that our study will encourage to develop more efficient electrocatalysts with more effective doping or surface functionalized structure by understanding the dopant nature.

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Unraveling the Hydrogen Evolution Reaction Active Sites in N‐Functionalized Interconnected Graphene Quantum Dots

Cited by 9 publications

References 50 publications

Integration of Nitrogen-Doped Graphene Oxide Dots with Au Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution

Integration of Nitrogen-Doped Graphene Oxide Dots with Au Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution

Low Dimensional Carbon-Based Catalysts for Efficient Photocatalytic and Photo/Electrochemical Water Splitting Reactions

Role of Specific N-Containing Active Sites in Interconnected Graphene Quantum Dots for the Enhanced Electrocatalytic Activity towards Oxygen Evolution Reaction

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