A cost-effective and highly efficient oxygen evolution reaction (OER) electrocatalyst will be significant for the future energy scenario. The emergence of the core-shell heterostructure has invoked new feasibilities to inspire the full potential of non-precious-metal candidates. The shells always have a large thickness, affording robust mechanical properties under harsh reaction conditions, which limits the full exposure of active sites with highly intrinsic reactivity and extrinsic physicochemical characters for optimal performance. Herein, a nanosized CoNi hydroxide@hydroxysulfide core-shell heterostructure is fabricated via an ethanol-modified surface sulfurization method. Such a synthetic strategy is demonstrated to be effective in controllably fabricating a core-shell heterostructure with an ultrathin shell (4 nm) and favorable exposure of active sites, resulting in a moderately regulated electronic structure, remarkably facilitated charge transfer, fully exposed active sites, and a strongly coupled heterointerface for energy electrocatalysis. Consequently, the as-obtained hydroxide@hydroxysulfide core-shell is revealed as a superior OER catalyst, with a small overpotential of 274.0 mV required for 10.0 mA cm-2 , a low Tafel slope of 45.0 mV dec-1 , and a favorable long-term stability in 0.10 M KOH. This work affords fresh concepts and strategies for the design and fabrication of advanced core-shell heterostructures, and thus opens up new avenues for the targeted development of high-performance energy materials.

A Nanosized CoNi Hydroxide@Hydroxysulfide Core-Shell Heterostructure for Enhanced Oxygen Evolution.

Boosting H 2 Generation Coupled with Selective Oxidation of Methanol into Value‐Added Chemical over Cobalt Hydroxide@Hydroxysulfide Nanosheets Electrocatalysts

NiCo-Based Electrocatalysts for the Alkaline Oxygen Evolution Reaction: A Review

Electrochemical water splitting is a sustainable and feasible strategy for hydrogen production but is hampered by the sluggish anodic oxygen evolution reaction (OER). Herein, an effective approach is introduced to significantly decrease the cell voltage by replacing the anodic OER with a urea oxidation reaction (UOR). A Ni2P/NiMoP nanosheet catalyst with a hierarchical architecture is uniformly grown on a nickel foam (NF) substrate through a simple hydrothermal and phosphorization method. The Ni2P/NiMoP achieves impressive HER activity, with a low overpotential of only 22 mV at 10 mA cm–2 and a low Tafel slope of 34.5 mV dec–1. In addition, the oxidation voltage is significantly reduced from 1.49 V to 1.33 V after the introduction of 0.33 M urea. Notably, a two-electrode electrolyzer employing Ni2P/NiMoP as a bifunctional catalyst exhibits a current density of 10 mA cm–2 at a cell voltage of 1.35 V and excellent long-term durability after 80 h.

Ni2P/NiMoP heterostructure as a bifunctional electrocatalyst for energy-saving hydrogen production

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/aenm.202101180

Progress and Perspectives in Photo- and Electrochemical-Oxidation of Biomass for Sustainable Chemicals and Hydrogen Production

The increasing need for clean and sustainable energy inspires researchers to explore low-cost nonprecious metal electrocatalysts for advanced energy storage and conversion. Herein, we develop a rea...

Reactive Template-Derived CoFe/N-Doped Carbon Nanosheetsas Highly Efficient Electrocatalysts toward Oxygen Reduction, OxygenEvolution, and Hydrogen Evolution

Developing earth-abundant, highly active, and durable electrocatalysts for the oxygen evolution reaction (OER) is very important for many renewable energy conversion processes. Herein, we report a novel OER electrocatalyst of NiCo layered double hydroxide@NiCo-hydroxysulfide (NiCo-LDH@HOS) nanosheet arrays, which are prepared by a rapid room-temperature sulfurization of the surface of NiCo-LDH nanosheets grown on Ni foam. The surface sulfurization exerts important influences/changes on the structure, composition, surface properties and chemistry of NiCo-LDH. After surface sulfurization, the resulted NiCo-hydroxysulfide layer armor improved electrical conductivity and chemical resistance to alkaline electrolyte, delivers a stable current density of 10.0 mA cm–2 at a low overpotential of 293 mV in 0.1 M KOH solution, maintaining high stability during a 62 h test. The achieved enhanced oxygen evolution activity and improved durability are superior to those of NiCo-LDH nanosheets and benchmark commercial RuO2...

Surface Sulfurization of NiCo-Layered Double Hydroxide Nanosheets Enable Superior and Durable Oxygen Evolution Electrocatalysis

Development of highly efficient nonprecious metal (NPM) catalysts for oxygen reduction reaction (ORR) in acidic media is challenging but of great significance. Herein, an effective ORR catalyst based on Fe nanoparticles encapsulated by S,N-codoped few-layer defective carbon (Fe@S,N-DC) was synthesized via a microwave-assisted strategy. The obtained Fe@S,N-DC nanocomposite showed a remarkable electrocatalytic activity toward ORR in acidic media, with a half-wave potential (E1/2) of +0.785 V versus reversible hydrogen electrode, which was 80 mV more positive than that of the sulfur-free counterpart (Fe@N-DC). Furthermore, due to the protection by the S,N-codoped carbon shell, the Fe@S,N-DC nanocomposite displayed apparent stability with only a 13 mV negative shift of E1/2 after 10,000 cycles and excellent tolerance to methanol. X-ray absorption near-edge spectroscopy measurements confirmed the formation of multiple defective sites on the S,N-codoped carbon surface and strong interfacial electron transfer from the Fe core to the outer carbon surface, as compared to the sulfur-free counterpart. The enriched electron density on the defective carbon surface of Fe@S,N-DC, induced by the interfacial electron transfer, facilitated the reduction of O2 to OOH*, leading to enhanced ORR performance. These results shed light on the significance of S doping in Fe-N-C catalysts in the design of high-performance NPM catalysts for ORR in acidic media.

Iron Nanoparticles Encapsulated in S,N-Codoped Carbon: Sulfur Doping Enriches Surface Electron Density and Enhances Electrocatalytic Activity toward Oxygen Reduction.

An oxide catalyst plays an important role in environmental catalysis. Metal chlorides are widely used as precursors in the preparation of oxide catalysts. However, residual chlorine usually influen...

Panpan Hao

Papers

Boosting H 2 Generation Coupled with Selective Oxidation of Methanol into Value‐Added Chemical over Cobalt Hydroxide@Hydroxysulfide Nanosheets Electrocatalysts

Reactive Template-Derived CoFe/N-Doped Carbon Nanosheetsas Highly Efficient Electrocatalysts toward Oxygen Reduction, OxygenEvolution, and Hydrogen Evolution

Surface Sulfurization of NiCo-Layered Double Hydroxide Nanosheets Enable Superior and Durable Oxygen Evolution Electrocatalysis

Iron Nanoparticles Encapsulated in S,N-Codoped Carbon: Sulfur Doping Enriches Surface Electron Density and Enhances Electrocatalytic Activity toward Oxygen Reduction.

Effect of Residual Chlorine on the Catalytic Performance of Co3O4 for CO Oxidation