Morphology and surface chemistry engineering toward pH-universal catalysts for hydrogen evolution at high current density

Nature Communications, Год журнала: 2019, Номер 10(1)

Опубликована: Янв. 11, 2019

Large-scale implementation of electrochemical hydrogen production requires several fundamental issues to be solved, including understanding the mechanism and developing inexpensive electrocatalysts that work well at high current densities. Here we address these challenges by exploring roles morphology surface chemistry, develop efficient for evolution. Three model are flat platinum foil, molybdenum disulfide microspheres, microspheres modified carbide nanoparticles. The last catalyst is highly active evolution independent pH, with low overpotentials 227 mV in acidic medium 220 alkaline a density 1000 mA cm-2, because enhanced transfer mass (reactants bubbles) fast reaction kinetics due oxygen groups formed on during Our may guide rational design

Язык: Английский

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Integrating the active OER and HER components as the heterostructures for the efficient overall water splitting

Nano Energy, Год журнала: 2017, Номер 44, С. 353 - 363

Опубликована: Дек. 13, 2017

Язык: Английский

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Heterostructured Electrocatalysts for Hydrogen Evolution Reaction Under Alkaline Conditions

Nano-Micro Letters, Год журнала: 2018, Номер 10(4)

Опубликована: Окт. 1, 2018

The hydrogen evolution reaction (HER) is a half-cell in water electrolysis for producing gas. In industrial electrolysis, the HER often conducted alkaline media to achieve higher stability of electrode materials. However, kinetics medium slow relative that acid because low concentration protons former. Under latter conditions, entire process will require additional effort obtain by dissociation near or on catalyst surface. Heterostructured catalysts, with fascinating synergistic effects derived from their heterogeneous interfaces, can provide multiple functional sites overall process. At present, activity most active known heterostructured catalysts surpasses (platinum-based heterostructures) approaches (noble-metal-free commercial Pt/C under demonstrating an infusive potential break through bottlenecks. This review summarizes representative and recent medium. basics principles conditions are first introduced, followed discussion latest advances with/without noble-metal-based heterostructures. Special focus placed enhancing rate accelerating Volmer step. aims overview current developments as well design future development nano- micro-sized electrocatalysts.

Язык: Английский

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Recent Advances in Design of Electrocatalysts for High‐Current‐Density Water Splitting

Advanced Materials, Год журнала: 2021, Номер 34(16)

Опубликована: Дек. 4, 2021

Abstract Electrochemical water splitting technology for producing “green hydrogen” is important the global mission of carbon neutrality. Electrocatalysts with decent performance at high current densities play a central role in industrial implementation this technology. This field has advanced immensely recent years, as witnessed by many types catalysts designed and synthesized toward industriallyrelevant (>200 mA cm –2 ). By discussing advances field, several key aspects are summarized that affect catalytic high‐current‐density electrocatalysis, including dimensionality catalysts, surface chemistry, electron transport path, morphology, catalyst‐electrolyte interplay. The multiscale design strategy considers these comprehensively developing electrocatalysts highlighted. perspectives on future directions emerging also put forward.

Язык: Английский

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Bifunctional Heterostructured Transition Metal Phosphides for Efficient Electrochemical Water Splitting

Advanced Functional Materials, Год журнала: 2020, Номер 30(34)

Опубликована: Июнь 29, 2020

Abstract Reducing green hydrogen production costs is essential for developing a economy. Developing cost‐effective electrocatalysts water electrolysis thus of great research interest. Among various material candidates, transition metal phosphides (TMP) have emerged as robust bifunctional both the evolution reaction (HER) and oxygen (OER) due to their phases tunable electronic structure. Recently, heterostructured catalysts exhibited significantly enhanced activities toward HER/OER. The enhancement can be attributed increased amount accessible active sites, accelerated mass/charge transfer, optimized adsorption intermediates, which arise from synergistic effects heterostructure. Herein, comprehensive overview recent progress TMP‐based heterostructure introduced provide an insight into preparation corresponding mechanisms. It starts with summarizing general fundamental aspects HER/OER effect heterostructures catalytic activity. Next, innovational strategies design construct overall splitting activity, well related mechanisms, are discussed in detail. Finally, summary perspective further opportunities challenges highlighted development points practical application mechanistic studies.

Язык: Английский

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High-Entropy Alloys as a Platform for Catalysis: Progress, Challenges, and Opportunities

ACS Catalysis, Год журнала: 2020, Номер 10(19), С. 11280 - 11306

Опубликована: Сен. 17, 2020

High-entropy alloys (HEAs), which are defined as near-equimolar of five or more elements, attracting ever increasing attention because the unique properties in a variety applications. Recently, HEAs have already exhibited remarkable catalytic performance toward several thermal-driven and electrocatalytic reactions. not only regulate electronic geometric structures to large degree but also serve platform construct catalysts with unexpected performance. Herein, recent advances regarding HEA-based catalysis systematically summarized, special focus on synthetic methods for catalysts, performance, mechanistic understanding. Moreover, challenges future opportunities this research area carefully discussed. A series open questions promising directions be explored proposed, including methods, regulation properties, identification active centers, applications into photocatalysis. This Review provides an overview about progress, challenges, catalysis.

Язык: Английский

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Platinum single-atom catalyst coupled with transition metal/metal oxide heterostructure for accelerating alkaline hydrogen evolution reaction

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Июнь 18, 2021

Single-atom catalysts provide an effective approach to reduce the amount of precious metals meanwhile maintain their catalytic activity. However, sluggish activity for alkaline water dissociation has hampered advances in highly efficient hydrogen production. Herein, we develop a single-atom platinum immobilized NiO/Ni heterostructure (PtSA-NiO/Ni) as evolution catalyst. It is found that Pt single atom coupled with enables tunable binding abilities hydroxyl ions (OH*) and (H*), which efficiently tailors energy promotes H* conversion accelerating reaction. A further enhancement achieved by constructing PtSA-NiO/Ni nanosheets on Ag nanowires form hierarchical three-dimensional morphology. Consequently, fabricated catalyst displays high performances quite mass 20.6 mg-1 at overpotential 100 mV, significantly outperforming reported catalysts.

Язык: Английский

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Phosphorus-Doped Co₃O₄ Nanowire Array: A Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting

ACS Catalysis, Год журнала: 2018, Номер 8(3), С. 2236 - 2241

Опубликована: Фев. 6, 2018

It is vitally essential to design highly efficient and cost-effective bifunctional electrocatalysts toward water splitting. Herein, we report the development of P-doped Co3O4 nanowire array on nickel foam (P-Co3O4/NF) from through low-temperature annealing, using NaH2PO2 as P source. As a 3D catalyst, such P-Co3O4/NF demonstrates superior performance for oxygen evolution reaction with low overpotential (260 mV at 20 mA cm–2), small Tafel slope (60 dec–1), satisfying durability in 1.0 M KOH. Density functional theory calculations indicate that P-Co3O4 has free-energy value much smaller than pristine potential determining step reaction. Such also performs efficiently hydrogen reaction, two-electrode alkaline electrolyzer assembled by P8.6-Co3O4/NF both anode cathode needs only 1.63 V reach water-splitting current 10 cm–2.

Язык: Английский

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Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting

Energy & Environmental Science, Год журнала: 2019, Номер 12(2), С. 572 - 581

Опубликована: Янв. 1, 2019

Identification of active catalyst surface phases and the influence dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting.

Язык: Английский

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Se-Doping Activates FeOOH for Cost-Effective and Efficient Electrochemical Water Oxidation

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(17), С. 7005 - 7013

Опубликована: Апрель 1, 2019

Ni or Co is commonly required in efficient electrocatalysts for oxygen evolution reaction (OER). Although Fe much more abundant and cheaper, full-Fe Fe-rich catalysts suffer from insufficient activity. Herein, we discover that Se-doping can drastically promote OER on FeOOH develop a facile on-site electrochemical activation strategy achieving such Se-doped electrode via an FeSe precatalyst. Theoretical analysis systematic experiments prove enables as low-cost electrocatalyst. By optimizing the structure, industrial-level current output of 500 mA cm-2 secured at low overpotential 348 mV. The application practical solar-driven water splitting system demonstrates high stable solar-to-hydrogen efficiency 18.55%, making promising exploring new cost-effective highly active clean hydrogen production.

Язык: Английский

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