Increasing Electrocatalytic Oxygen Evolution Efficiency through Cobalt‐Induced Intrastructural Enhancement and Electronic Structure Modulation

Abstract

Electrolytic water splitting using surplus electricity represents one of the most cost-effective and promising strategies for hydrogen production. The high overpotential of the oxygenevolution reaction (OER) caused by the multi-electron transfer process with a high chemical energy barrier, however, limits its competitiveness. Here, a highly active and stable OER electrocatalyst was designed through a cobalt-induced intrastructural enhancement strategy combined with suitable electronic structure modulation. A carved carbon nanobox was embedded with tri-metal phosphide from a uniform NiÀ CoÀ Fe Prussian blue analogue (PBA) nanocube by sequential NH 3 • H 2 O etching and thermal phosphorization. The sample exhibited an OER activity in an alkaline medium, reaching a current density of 10 mA cm À 2 at an overpotential of 182 mV and displayed a small Tafel slope of 47 mV dec À 1 , superior to the most recently reported OER electrocatalysts. Moreover, it showed impressive electrocatalytic durability, increasing by approximately 2.7 % of operating voltage after 24 h of continuous testing. The excellent OER activity and stability are ascribed to a favorable transfer of mass and charge provided by the porous carbon shell, synergistic catalysis between the three-component metal phosphides originating from appropriate electronic structure modulation, more exposed catalytic sites on the hollow structure, and chainmail catalysis resulting from the carbon protective layer. It is foreseen that this successfully demonstrated design concept can be easily extended to other heterogeneous catalyst designs.

Co/MoC Nanoparticles Embedded in Carbon Nanoboxes as Robust Trifunctional Electrocatalysts for a Zn–Air Battery and Water Electrocatalysis

“…Over the past few years, many efforts have been made for the design and development of various advanced nonprecious metal-based electrocatalysts. − Among them, nitrogen-doped carbon (NC) materials confined with transition metal nanoparticles are indentified to be the promising electrocatalysts toward OER, HER, or ORR processes because of their intrinsic advantages of excellent electrical conductivity, rich active sites, and high activities . Recently, zeolitic imidazole frameworks (ZIFs) have been repeatedly proven to be ideal precursors for the preparation of metal–N-C catalysts, in which the metal centers and ligands of ZIF materials can supply transition metals and carbon sources doped with heteroatoms, respectively. − However, direct high-temperature carbonization strategy may result in a decrease in both nitrogen content and porosity of the prepared metal-embedded NC product, thereby greatly reducing the available active sites and limiting the mass transfer process, which will seriously affect the catalytic activity of the material .…”

Antifreezing and Nondrying Sensors of Ionic Hydrogels with a Double-Layer Structure for Highly Sensitive Motion Monitoring

“…In addition, the ionic hydrogel has low vapor pressure, high chemical stability, thermal stability, and resistance to extreme environments. , For the bottom layer of the hydrogel, the adhesion will decrease when the human skin is sweating. Therefore, mussel-inspired hydrogel, which is composed of dopamine or 3,4-dihydroxyphenylalanine ( l -Dopa), can be a pioneer candidate to address the above issues, − since marine mussels show a super capacity to adhere to various substrates (including organic and inorganic) under wet or dry environments. , The results of our previous work also demonstrated that mussel-inspired hydrogel exhibited 1.2 MPa adhesive strength under wet conditions.…”

Boosting the activity and stabilityviasynergistic catalysis of Co nanoparticles and MoC to construct a bifunctional electrocatalyst for high-performance and long-life rechargeable zinc–air batteries

“…[13][14][15][16] Currently, various advanced and low-cost non-precious metal-based electrocatalysts are being designed and developed. [17][18][19][20][21] Among these are nitrogen-doped carbon (NC) materials with transition metal nanoparticles as the main active sites. 22,23 Owing to the satisfactory inherent benefits of catalysts like outstanding conductivity of electrons, abundant active sites, and excellent activity, NC materials are considered promising electrocatalysts for OER or ORR processes.…”