Electrochemistry has recently gained increased attention as a versatile strategy for achieving challenging transformations at the forefront of synthetic organic chemistry. Electrochemistry's unique ability to generate highly reactive radical and radical ion intermediates in a controlled fashion under mild conditions has inspired the development of a number of new electrochemical methodologies for the preparation of valuable chemical motifs. Particularly, recent developments in electrosynthesis have featured an increased use of redox-active electrocatalysts to further enhance control over the selective formation and downstream reactivity of these reactive intermediates. Furthermore, electrocatalytic mediators enable synthetic transformations to proceed in a manner that is mechanistically distinct from purely chemical methods, allowing for the subversion of kinetic and thermodynamic obstacles encountered in conventional organic synthesis. This review highlights key innovations within the past decade in the area of synthetic electrocatalysis, with emphasis on the mechanisms and catalyst design principles underpinning these advancements. A host of oxidative and reductive electrocatalytic methodologies are discussed and are grouped according to the classification of the synthetic transformation and the nature of the electrocatalyst.

Electrocatalysis as an enabling technology for organic synthesis.

A Growing Appreciation for the Role of LiF in the Solid Electrolyte Interphase

Energy is an indispensable component in the development of modern society. Nanostructured transition metal phosphides (TMPs) have recently emerged as versatile and efficient catalysts in the fields of clean production of fossil fuels, renewable energies, and energy storage technologies. In this review, popular strategies to fabricate TMPs are initially summarized. Then, we present the diverse applications of TMPs as active catalysts in thermocatalysis, electrocatalysis, photocatalysis, and energy storage techniques, with special emphasis on the dependence of reaction activities on the features of TMPs. Throughout the various applications of TMPs, it can be inferred that TMPs themselves play key roles in some cases. While in other cases, it is the synergistic effect of surface oxidation and intrinsic TMPs that is responsible for the high reaction performances. At last, the future perspectives of TMPs are pointed out.

Recent advances in nanostructured transition metal phosphides: synthesis and energy-related applications

With the ever-increasing adaption of large-scale energy storage systems and electric devices, the energy storage capability of batteries and supercapacitors has faced increased demand and challenges. The electrodes of these devices have experienced radical change with the introduction of nano-scale materials. As new generation materials, heterostructure materials have attracted increasing attention due to their unique interfaces, robust architectures, and synergistic effects, and thus, the ability to enhance the energy/power outputs as well as the lifespan of batteries. In this review, the recent progress in heterostructure from energy storage fields is summarized. Specifically, the fundamental natures of heterostructures, including charge redistribution, built-in electric field, and associated energy storage mechanisms, are summarized and discussed in detail. Furthermore, various synthesis routes for heterostructures in energy storage fields are roundly reviewed, and their advantages and drawbacks are analyzed. The superiorities and current achievements of heterostructure materials in lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), lithium-sulfur batteries (Li-S batteries), supercapacitors, and other energy storage devices are discussed. Finally, the authors conclude with the current challenges and perspectives of the heterostructure materials for the fields of energy storage.

Emerging of Heterostructure Materials in Energy Storage: A Review.

2D/1D graphitic carbon nitride hybridized with titanate nanotubes (g-C3N4/TNTs) was prepared through a hydrothermal reaction–calcination method. The photocatalyst exhibited high degradation efficiency for sulfamethazine (SMT) through photocatalysis under simulated solar light. The optimized material was composed of anatase, rutile, titanate and g-C3N4 crystalline phases. In situ transformation of titanate to anatase and rutile with specific content proportion (∼80:20, P25-type composition) leaded to formation of nanoscale “hot spots” at rutile–anatase–titanate interfaces, and then subsequent charge transfer occurred. Large specific surface area of TNTs as skeleton resulted in high-efficient interface reaction, while heterojunction with g-C3N4 further extended the adsorption to visible light region and retarded electron-hole pairs recombination. Density functional theory (DFT) calculation indicated the SMT sites with high Fukui nucleophilic (f-) index prefered to be attacked by radacils. Reduced toxicity of SMT degradation intermediates, good reusability and stability of g-C3N4/TNTs all suggested the great application potential in practical water treatment area.

2D/1D graphitic carbon nitride/titanate nanotubes heterostructure for efficient photocatalysis of sulfamethazine under solar light: Catalytic “hot spots” at the rutile–anatase–titanate interfaces

https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.202014556

Inside Cover: Mn−O Covalency Governs the Intrinsic Activity of Co-Mn Spinel Oxides for Boosted Peroxymonosulfate Activation (Angew. Chem. Int. Ed. 1/2021)

Co3O4 with a high theoretical capacitance has been widely recognized as a promising electrode material for supercapacitor, but its poor electrical conductivity and stability limit its practical applications. Here, we developed an effective synthetic route to synthesize one-dimensional (1D) porous ZnO/Co3O4 heterojunction composites. Benefiting from the heterostructure to promote the charge transfer and protect Co3O4 from corrosion and the 1D porous structure to improve ion diffusion and prevent structural collapse in charge and discharge process, the as-prepared ZnO/Co3O4 composites exhibited an excellent capacitive performance and good cycling stability. The specific capacitance of the ZnO/Co3O4-450 (1135 F g–1 at 1 A g–1) was 1.4 times higher than that of Co3O4 (814 F g–1), and the high-rate performance for ZnO/Co3O4-450 was 4.9 times better than that of Co3O4. Also, approximately 83% of its specific capacitance was retained after 5000 cycles at 10 A g–1. Most importantly, the as-fabricated asymmetric s...

Porous ZnO-Coated Co3O4 Nanorod as a High-Energy-Density Supercapacitor Material.

Atrazine is a widely used herbicide and a typical toxic pollutant. TiO 2 -mediated photocatalysis is an efficient way to degrade such a refractory contaminate. In a photocatalyic process, great charge separation and efficient interparticle electron transfer are highly desired and are usually achieved through element doping and phase-junction optimization. However, in the traditional methods for synthesizing phase-junction TiO 2 , high phase transition temperature and appropriate adjustors are always needed. In this work, boron-doped (B-doped) TiO 2 with a tunable anatase/rutile ratio is successfully synthesized for efficient atrazine degradation by using a simple one-step calcination method, which is conducted below phase transition temperature with as-prepared Ti and B mixture as a precursor. The formation of the surface-phase junctions between anatase and rutile nanoparticles enables effective interparticle electron transfer and results in more efficient charge separation. Also, the B-doping serves as charge traps, which are able to mediate oxidative electron transfer. The prepared B-doped TiO 2 exhibits a higher photocatalytic activity for the degradation of atrazine, with a reaction rate of 4 times faster than that of the non-doped counterpart. The photogenerated reactive species and degradation intermediates of atrazine are identified, and the photocatalytic atrazine degradation mechanism is elucidated. This study provides a new approach to prepare phase-junction photocatalysts and demonstrates that the anatase/rutile ratio can be tuned by doping element. Such a “killing two birds with one arrow” strategy could be extended for preparing other photocatalysts for the degradation of various pollutants.

/pdf/photocatalytic-degradation-of-atrazine-by-boron-doped-tio2-2kdb1zmtfd.pdf

Photocatalytic degradation of atrazine by boron-doped TiO2 with a tunable rutile/anatase ratio

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/ange.202014556

Innentitelbild: Mn−O Covalency Governs the Intrinsic Activity of Co-Mn Spinel Oxides for Boosted Peroxymonosulfate Activation (Angew. Chem. 1/2021)

Electrode materials for high-rate supercapacitors are greatly desired. Among actively studied electrode materials, phosphide compounds with metallic features are recognized as such promising supercapacitor materials. In this work, considering the benefits of multimetal redox centers and superior electrical conductivity of ternary nickel–cobalt metal phosphides for improving the supercapacitor performance, urchin-like nickel–cobalt phosphide hollow spheres were prepared with a mild hydrothermal method followed by phosphorization. The formation process was explored using time-dependent experiments. The prepared material exhibited an excellent capacity of 761 C g–1 at a current density of 1 A g–1, with 693 C g–1 remaining even at 20 A g–1, which exhibited a high-rate capability with approximately 91.1% retention of its initial capacity. Moreover, the asymmetric supercapacitor assembled with the prepared NiCoP hollow sphere and activated carbon exhibited a maximum energy density of 35.6 W h kg–1 and maximum p...

Miao Gao

Papers

Inside Cover: Mn−O Covalency Governs the Intrinsic Activity of Co-Mn Spinel Oxides for Boosted Peroxymonosulfate Activation (Angew. Chem. Int. Ed. 1/2021)

Porous ZnO-Coated Co3O4 Nanorod as a High-Energy-Density Supercapacitor Material.

Photocatalytic degradation of atrazine by boron-doped TiO2 with a tunable rutile/anatase ratio

Innentitelbild: Mn−O Covalency Governs the Intrinsic Activity of Co-Mn Spinel Oxides for Boosted Peroxymonosulfate Activation (Angew. Chem. 1/2021)

Fabrication of Metallic Nickel–Cobalt Phosphide Hollow Microspheres for High-Rate Supercapacitors