Crystalline Ru-Decorated MOF-Derived Amorphous CoMo-LDH Nanosheet Arrays as Bifunctional Catalysts for Overall Natural Seawater Electrolysis.

The construction of an amorphous/crystalline heterostructure of MOF-derived electrocatalysts offers an intriguing pathway to improve hydrogen production efficiency, but it has received little attention. Here, we report crystalline Ru-decorated MOF-derived amorphous CoMo-LDH nanosheet arrays as highly active and robust bifunctional electrocatalysts for natural seawater electrolysis. Benefiting from the abundant interfaces, the Ru-CoMo-LDH catalyst exhibits excellent activity toward OER under fresh and natural seawater, in particular; it requires only 257 and 406 mV overpotential at 10 and 500 mA cm in 1 M KOH + Seawater, outperforming the benchmark RuO.

Boosting Urea-Assisted Natural Seawater Electrolysis in 3D Leaf-Like Metal-Organic Framework Nanosheet Arrays Using Metal Node Engineering.

Metal node engineering, which can optimize the electronic structure and modulate the composition of poor electrically conductive metal-organic frameworks, is of great interest for electrochemical natural seawater splitting. However, the mechanism underlying the influence of mixed-metal nodes on electrocatalytic activities is still ambiguous. Herein, a strategic design is comprehensively demonstrated in which mixed Ni and Co metal redox-active centers are uniformly distributed within NH-Fe-MIL-101 to obtain a synergistic effect for the overall enhancement of electrocatalytic activities.

Dopant-Induced Charge Redistribution on the 3D Sponge-like Hierarchical Structure of Quaternary Metal Phosphides Nanosheet Arrays Derived from Metal-Organic Frameworks for Natural Seawater Splitting.

Dopant-induced electron redistribution on transition metal-based materials has long been considered an emerging new electrocatalyst that is expected to replace noble-metal-based electrocatalysts in natural seawater electrolysis; however, their practical applications remain extremely daunting due to their sluggish kinetics in natural seawater. In this work, we developed a facile strategy to synthesize the 3D sponge-like hierarchical structure of Ru-doped NiCoFeP nanosheet arrays derived from metal-organic frameworks with remarkable hydrogen evolution reaction (HER) performance in natural seawater. Based on experimental results and density functional theory calculations, Ru-doping-induced charge redistribution on the surface of metal active sites has been found, which can significantly enhance the HER activity.

Highly Efficient and Stable Hydrogen Evolution from Natural Seawater by Boron-Doped Three-Dimensional NiP-MoO Heterostructure Microrod Arrays.

The rational design of highly active and stable electrocatalysts toward the hydrogen evolution reaction (HER) is highly desirable but challenging in seawater electrolysis. Herein we propose a strategy of boron-doped three-dimensional NiP-MoO heterostructure microrod arrays that exhibit excellent catalytic activity for hydrogen evolution in both alkaline freshwater and seawater electrolytes. The incorporation of boron into NiP-MoO heterostructure microrod arrays could modulate the electronic properties, thereby accelerating the HER.

Promoting High-Oxidation-State Metal Active Sites in a Hollow Ternary Metal Fluoride Nanoflake Array for Urea Electrolysis.

The adsorption ability of hydrogen, hydroxide, and oxygenic intermediates plays a crucial role in electrochemical water splitting. Electron-deficient metal-active sites can prompt electrocatalytic activity by improving the adsorption ability of intermediates. However, it remains a significant challenge to synthesize highly abundant and stable electron-deficient metal-active site electrocatalysts.

Coupling Amorphous Ni Hydroxide Nanoparticles with Single-Atom Rh on Cu Nanowire Arrays for Highly Efficient Alkaline Seawater Electrolysis.

Exploring efficient catalysts for alkaline seawater electrolysis is highly desired yet challenging. Herein, coupling single-atom rhodium with amorphous nickel hydroxide nanoparticles on copper nanowire arrays is designed as a new active catalyst for the highly efficient alkaline seawater electrolysis. We found that an amorphous Ni(OH) nanoparticle is an effective catalyst to accelerate the water dissociation step.

In situ multi-dimensional actuation measurement method for tensile actuation of paraffin-infiltrated multi-wall carbon nanotube yarns.

We introduce an experimental setup for the simultaneous measurement of axial and radial strain variations of a hybrid carbon nanotube (CNT) yarn actuator, where a paraffin wax is melt-infiltrated inside the CNT yarn. Such a hybrid yarn system has been known as a Joule-heating-driven tensile/torsional actuator due to a large volume expansion of the infiltrated paraffin upon a solid-to-liquid phase transition. During the operation of this actuator, however, the axial strain variations along the yarn axis and the diameter change of the yarn, which is the radial strain variations perpendicular to the yarn axis, had been measured separately, which prohibits the exact understanding of the whole actuation dynamics.

Quantum Hall conductance of graphene combined with charge-trap memory operation.

The combination of quantum Hall conductance and charge-trap memory operation was qualitatively examined using a graphene field-effect transistor. The characteristics of two terminal quantum Hall conductance appeared clearly on the background of a huge conductance hysteresis during a gate-voltage sweep for a device using monolayer graphene as a channel,hexagonal boron-nitride flakes as a tunneling dielectric and defective silicon oxide as the charge storage node. Even though there was a giant shift of the charge neutrality point, the deviation of quantized resistance value at the state of filling factor 2 was less than 1.