Metal Organic Frameworks Derived Layered Double Hydroxide Nanosheets for Electrochemical Energy Storage and Conversion

Abstract Porous materials are promising for energy applications and MOF‐derived layered double hydroxide (LDH) nanosheets vertically align on the conductive substrates showed an ultrathin porous morphology with tunable coordination environments for the metallic sites. This unique structure provides larger surface area, better intrinsic electrochemical activity than conventional LDH nanosheets. Herein, the synthetic strategies of MOF‐derived LDHs and their promising applications in electrochemistry are reviewed, presenting the significant potential and challenges of MOFs‐derived LDH nanosheets in advanced energy storage and conversion applications, providing an effective platform for efficient and sustainable MOFs‐based systems in future

Nano-Graphite Prepared by Rapid Pulverization as Anode for Lithium-Ion Batteries

Reducing the particle size of active material is an effective solution to the poor rate performance of the lithium-ion battery. In this study, we proposed a facile strategy for the preparation of nano-graphite as an anode for a lithium-ion battery via the rapid mechanical pulverization method. It is the first time that diamond particle was selected as the medium to achieve high preparation efficiency and low energy consumption. The as-prepared nano-graphite with the size from 10 to 300 nm displays an intact structure and high specific surface area. The introduced oxygen atoms increased the wettability of nano-graphite electrode and lowered its polarization. The nano-graphite prepared from three hours of grinding shows an excellent reversible capacity of 191 mAh g−1, at a rate of 5 C, after 480 cycles, along with an increase of 86% in capacity, at 1 C, in comparison with pristine graphite. The highlight of this strategy is to optimize the current preparation method. The good electrochemical performance comes from the combined effect of nano-scale particle size, large specific surface area, and continuous mesopores

Organocatalytic Synthesis of α-Aminonitriles: A Review

α-Aminonitriles, which have anticancer, antibacterial, antiviral, and antifungal properties, have played an important role in pharmacology. Furthermore, they can also be used to synthesize natural and unnatural amino acids. The main bottleneck in the commercialization of these products is their large-scale production with controlled chirality. A variety of methods have been used to synthesize α-aminonitriles. Among other reported methods for preparing α-aminonitriles, the Strecker reaction is considered appropriate. Recent developments, however, have enabled the α-cyanation of tertiary and secondary amines by functionalizing the carbon–hydrogen (C–H) bond as an attractive alternative procedure for the preparation of α-aminonitriles in the presence of an oxidant and a cyanide source. In most cases, these reactions are catalyzed by transition metal catalysts, such as Fe, Cu, Rh, V, Au, Ru, Mo, Pt, Re, and Co, or by photocatalysts. As an alternative, organocatalysts can also be used to produce aminonitriles. Although there have been numerous reviews on the preparation of α-aminonitriles, no such reviews have been published specifically on the organocatalyzed synthesis of α-aminonitriles. Organocatalysis plays a significant role in synthesizing α-aminonitriles via Strecker-type reactions and cross dehydrogenative coupling reactions (CDC). In this mini review, we discuss the organocatalyzed synthesis of these molecules. A review of new organocatalysts for the synthesis of aminonitriles is expected to provide insight into the development of new industrial catalysts

Organocatalytic Synthesis of α-Aminonitriles: A Review

α-Aminonitriles, which have anticancer, antibacterial, antiviral, and antifungal properties, have played an important role in pharmacology. Furthermore, they can also be used to synthesize natural and unnatural amino acids. The main bottleneck in the commercialization of these products is their large-scale production with controlled chirality. A variety of methods have been used to synthesize α-aminonitriles. Among other reported methods for preparing α-aminonitriles, the Strecker reaction is considered appropriate. Recent developments, however, have enabled the α-cyanation of tertiary and secondary amines by functionalizing the carbon–hydrogen (C–H) bond as an attractive alternative procedure for the preparation of α-aminonitriles in the presence of an oxidant and a cyanide source. In most cases, these reactions are catalyzed by transition metal catalysts, such as Fe, Cu, Rh, V, Au, Ru, Mo, Pt, Re, and Co, or by photocatalysts. As an alternative, organocatalysts can also be used to produce aminonitriles. Although there have been numerous reviews on the preparation of α-aminonitriles, no such reviews have been published specifically on the organocatalyzed synthesis of α-aminonitriles. Organocatalysis plays a significant role in synthesizing α-aminonitriles via Strecker-type reactions and cross dehydrogenative coupling reactions (CDC). In this mini review, we discuss the organocatalyzed synthesis of these molecules. A review of new organocatalysts for the synthesis of aminonitriles is expected to provide insight into the development of new industrial catalysts

CuZr Metal Glass Powder as Electrocatalysts for Hydrogen and Oxygen Evolution Reactions

For the practical application of water electrolysis, it is essential to develop cost-effective and high efficiency electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evaluation reaction (OER). In this work, we applied CuZr metallic glass powder, after chemical dealloying treatment, as electrocatalysts. The as-prepared sample had both the increased specific area and optimized surface composition of an efficient catalyst. During the HER and OER processes, the dealloyed CuZr sample displayed overpotential of 195 mV and 310 mV at current density of 10 mA cm−2, respectively. A two-electrode water splitting cell, using the as-prepared CuZr sample, exhibited high stability towards a high current density of 500 mA cm−2, and lower overpotential, compared to a Pt/C//IrO2 cell, during the 10 mA cm−2 constant current density aging test

CuZr Metal Glass Powder as Electrocatalysts for Hydrogen and Oxygen Evolution Reactions

For the practical application of water electrolysis, it is essential to develop cost-effective and high efficiency electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evaluation reaction (OER). In this work, we applied CuZr metallic glass powder, after chemical dealloying treatment, as electrocatalysts. The as-prepared sample had both the increased specific area and optimized surface composition of an efficient catalyst. During the HER and OER processes, the dealloyed CuZr sample displayed overpotential of 195 mV and 310 mV at current density of 10 mA cm−2, respectively. A two-electrode water splitting cell, using the as-prepared CuZr sample, exhibited high stability towards a high current density of 500 mA cm−2, and lower overpotential, compared to a Pt/C//IrO2 cell, during the 10 mA cm−2 constant current density aging test

Electrochemical CO2 reduction: Implications of electrocatalyst’s surface hydroxyl groups

Electrochemical CO2 reduction (ECCO2R) is a viable and promising approach for converting the greenhouse gas carbon dioxide into useful chemicals and fuels. Electrochemical activity and product selectivity are essential for this purpose. The ECCO2R can lead to the formation of a wide variety of by-products, which is primarily dictated by the nature of electrocatalysts. Surface modification of electrocatalysts with oxide and/or hydroxide moieties can be a simple yet effective strategy to improve activity and selectivity of the ECCO2R process. This article attempts to review and identify relationship between the surface hydroxylation of electrocatalysts and the product selectivity. Impact of electrocatalyst’s surface modification with oxide/hydroxide on activity, product selectivity, intermediate stability, plausible mechanism and catalyst evolution during the ECCO2R is highlighted by focusing on select and representative research findings. The review finds that the product selectivity is highly dependent not only on the presence of OH group on the electrocatalysts' surfaces but also the type and distribution of the group. Moreover, the selectivity can be tuned by introducing and controlling the density of surface OH. Future perspectives and challenges are also emphasized