In Situ Grown Co-Based Interstitial Compounds: Non-3d Metal and Non-Metal Dual Modulation Boosts Alkaline and Acidic Hydrogen Electrocatalysis.

Interfacial engineering and elemental doping are the two parameters to enhance the catalytic behavior of cobalt nitrides for the alkaline hydrogen evolution reaction (HER). However, simultaneously combining these two parameters to improve the HER catalytic properties of cobalt nitrides in alkaline media is rarely reported and also remains challenging in acidic media. Herein, it is demonstrated that high-valence non-3d metal and non-metal integration can simultaneously achieve Co-based nitride/oxide interstitial compound phase boundaries on stainless steel mesh (denoted Mo-Co N/N-CoO) for efficient HER in alkaline and acidic media.

Sub-Thick Electrodes with Enhanced Transport Kinetics via In Situ Epitaxial Heterogeneous Interfaces for High Areal-Capacity Lithium Ion Batteries.

The ever-growing portable electronics and electric vehicle draws the attention of scaling up of energy storage systems with high areal-capacity. The concept of thick electrode designs has been used to improve the active mass loading toward achieving high overall energy density. However, the poor rate capabilities of electrode material owing to increasing electrode thickness significantly affect the rapid transportation of ionic and electron diffusion kinetics.

Advanced Tri-Layer Carbon Matrices with π-π Stacking Interaction for Binder-Free Lithium-Ion Storage.

Enabling materials with distinct features toward achieving high-performance energy storage devices is of huge importance but highly challenging. Commercial carbon cloth (CC), because of its appealing chemical and mechanical properties, has been proven to be an excellent conductive substrate for active electrode materials. However, its performance is notably poor when directly used as an electrode in energy storage, due to its low theoretical capacity and surface area.

Polypyrrole Hollow Microspheres with Boosted Hydrophilic Properties for Enhanced Hydrogen Evolution Water Dissociation Kinetics.

The water dissociation step (HO + M + e → M - H + OH) is a crucial one toward achieving high-performance hydrogen evolution reaction (HER). The application of electronic conducting polymers (ECPs), such as polypyrrole (PPy), as the electrocatalyst for HER is rarely reported because of their poor adsorption energy per water molecule, which hinders the Volmer step. Herein, we strongly enrich PPy hollow microspheres (PPy-HMS) with attractive HER activity by enhancing their hydrophilic properties through hybridization with good water affinity SiO.

Asymmetric Pseudocapacitors Based on Interfacial Engineering of Vanadium Nitride Hybrids.

Vanadium nitride (VN) shows promising electrochemical properties as an energy storage devices electrode, specifically in supercapacitors. However, the pseudocapacitive charge storage in aqueous electrolytes shows mediocre performance. Herein, we judiciously demonstrate an impressive pseudocapacitor performance by hybridizing VN nanowires with pseudocapacitive 2D-layered MoS nanosheets.

Hierarchical CoO@N-Doped Carbon Composite as an Advanced Anode Material for Ultrastable Potassium Storage.

Cobalt oxide (CoO) delivers a poor capacity when applied in large-sized alkali metal-ion systems such as potassium-ion batteries (KIBs). Our density functional theory calculation suggests that this is due to poor conductivity, high diffusion barrier, and weak potassium interaction. N-doped carbon can effectively attract potassium ions, improve conductivity, and reduce diffusion barriers.

A Simple and Scalable Approach To Remarkably Boost the Overall Water Splitting Activity of Stainless Steel Electrocatalysts.

The stainless steel mesh (SSM) has received growing consideration as an electrocatalyst for efficient hydrogen and oxygen evolution reactions. Recently, the application of SSM as an oxygen evolution reaction (OER) electrocatalyst has been more promising, while its hydrogen evolution reaction (HER) catalytic activity is very low, which definitely affects its overall water splitting activity. Herein, a simple chemical bath deposition (CBD) method followed by phosphorization is employed to significantly boost the overall water splitting performance of SSM.

Co O @Cu-Based Conductive Metal-Organic Framework Core-Shell Nanowire Electrocatalysts Enable Efficient Low-Overall-Potential Water Splitting.

In the work reported herein, the electrocatalytic properties of Co O in hydrogen and oxygen evolution reactions have been significantly enhanced by coating a shell layer of a copper-based metal-organic framework on Co O porous nanowire arrays and using the products as high-performance bifunctional electrocatalysts for overall water splitting. The coating of the copper-based metal-organic framework resulted in the hybridization of the copper-embedded protective carbon shell layer with Co O to create a strong Cu-O-Co bonding interaction for efficient hydrogen adsorption. The hybridization also led to electronically induced oxygen defects and nitrogen doping to effectively enhance the electrical conductivity of Co O .

Efficient Hydrogen Evolution Activity and Overall Water Splitting of Metallic CoN Nanowires through Tunable d-Orbitals with Ultrafast Incorporation of FeOOH.

Cobalt nitride electrocatalysts have been investigated and proven to show excellent oxygen evolution reaction activity owing to their excellent metallic properties, but their hydrogen evolution reaction (HER) properties are rarely reported because of their unsatisfactory molecular energy level, especially the d-orbital. Herein, taking CoN as a case study, we tune the d-orbital of metallic CoN nanowires via rapid formation of iron oxyhydroxide (FeOOH). Experimental analyses show that FeOOH@CoN/SSM exhibits excellent HER catalytic activity with considerable low onset overpotential (22 mV), small Tafel slope (34 mV dec), and excellent stability at current densities ranging from 20 to 100 mA cm.