Coordination Effect-Promoted Durable Ni(OH)_(2) for Energy-Saving Hydrogen Evolution from Water/ Methanol Co-Electrocatalysis

Electrocatalytic water splitting is a viable technique for generating hydrogen but is precluded from the sluggish kinetics of oxygen evolution reactions(OER).Small molecule oxidation reactions with lower working potentials,such as methanol oxidation reactions,are good alternatives to OER with faster kinetics.However,the typically employed Ni-based electrocatalysts have poor activity and stability.Herein,a novel three-dimensional(3D)-networking Modoped Ni(OH)_(2) with ultralow Ni-Ni coordination is synthesized,which exhibits a high MOR activity of 100 mA cm^(−2) at 1.39 V,delivering 28 mV dec^(−1) for the Tafel slope.Meanwhile,hydrogen evolution with value-added formate co-generation is boosted with a current density of more than 500 mA cm^(−2) at a cell voltage of 2.00 V for 50 h,showing excellent stability in an industrial alkaline concentration(6 M KOH).Mechanistic studies based on density functional the-ory and X-ray absorption spectroscopy showed that the improved performance is mainly attributed to the ultralow Ni-Ni coordination,3D-networking structures and Mo dopants,which improve the catalytic activity,increase the active site density and strengthen the Ni(OH)_(2)3D-networking structures,respectively.This study paves a new way for designing electrocatalysts with enhanced activity and durability for industrial energy-saving hydrogen production.

Sodium Alginate/Carboxyl-Functionalized Graphene Composite Hydrogel Via Neodymium Ions Coordination

A facile method for the preparation of sodium alginate(SA)/carboxyl-functionalized graphene(G-COOH)composite hydrogel was developed. Based on the coordination ability of lanthanide ions to the carboxyl groups, a series of hydrogel derived from different ratios of SA and G-COOH was fabricated by neodymium(Nd^(3+)) ions coordination. A relatively uniform layered structure was recorded by SEM at the interior of SA/G-COOH hydrogel. Several parameters such as water content, swelling ratio(SR), tensile test and solvent resistance were also investigated. The SA/G-COOH composite hydrogel showed excellent mechanical strength, and the tensile strength of SA/G-COOH composite hydrogel reaches 53.72 MPa at high water content. Due to the coordination ability of Nd^(3+) ions, the hydrogel also exhibited an excellent solvent resistance and stability.

Copper-based metal-organic frameworks for electrochemical reduction of CO_(2)

The electrochemical CO_(2)reduction reaction(CO_(2)ER)is an emerging process that involves utilizing CO_(2)to produce valuable chemicals and fuels by consuming excess electricity from renewable sources.Recently,Cu and Cu-based nanoparticles,as earth-abundant and economical metal sources,have been attracting significant interest.The chemical and physical properties of Cu-based nanoparticles are modified by different strategies,and CO_(2)can be converted into multicarbon products.Among various Cu-based nanoparticles,Cu-based metal-organic frameworks(MOFs)are gaining increasing interest in the field of catalysis because of their textural,topological,and electrocatalytic properties.In this minireview,we summarized and highlighted the main achievements in the research on Cu-based MOFs and their advantages in the CO_(2)ER as electrocatalysts,supports,or precursors.

Copper-cobalt-nickel oxide nanowire arrays on copper foams as self-standing anode materials for lithium ion batteries

Numerous scientists are in the pursuit of energy storage materials with high energy and high power density by assembly of electrochemically active materials into conductive scaffolds,owing to the emerging need for next-generation energy storage devices.In this architectures,the active materials bonded to the conductive scaffold can provide a robust and free-standing structure,which is crucial to the fabrication of materials with high gravimetric capacity.Thus,hierarchical copper-cobalt-nickel ternary oxide(CuCoNi-oxide) nanowire arrays grown from copper foam were successfully fabricated as freestanding anode materials for lithium ion batteries(LIBs).CuCoNi-oxide nanowire arrays could provide more active sites owing to the hyperbranched structure,leading to a better specific capacity of 1191 mAh/g,cycle performance of 73% retention in comparison to CuO nanowire structure,which exhibited a specific capacity of 1029 mAh/g and capacity retention of 43%,respectively.

WAEAS:An Optimization Scheme of EAS Scheduler for Wearable Applications

The rapid development of wearable computing technologies has led to an increased involvement of wearable devices in the daily lives of people.The main power sources of wearable devices are batteries;so,researchers must ensure high performance while reducing power consumption and improving the battery life of wearable devices.The purpose of this study is to analyze the new features of an Energy-Aware Scheduler(EAS)in the Android 7.1.2 operating system and the scarcity of EAS schedulers in wearable application scenarios.Also,the paper proposed an optimization scheme of EAS scheduler for wearable applications(Wearable-Application-optimized Energy-Aware Scheduler(WAEAS)).This scheme improves the accuracy of task workload prediction,the energy efficiency of central processing unit core selection,and the load balancing.The experimental results presented in this paper have verified the effectiveness of a WAEAS scheduler.