1D Covalent Organic Frameworks with Tunable Dual-Cobalt Synergistic Sites for Efficient CO Photoreduction.

Diatomic catalysts enhance photocatalytic CO reduction through synergistic effects. However, precisely regulating the distance between two catalytic centers to achieve synergistic catalysis poses significant challenges. In this study, a series of one-dimensional (1D) covalent organic frameworks (COFs) are designed with adjustable micropores to facilitate efficient CO photoreduction.

1D Anionic Covalent Organic Frameworks With Directed Migration of Alkali Metal Ions for High Ionic Conductivity.

Rational construction of high-performance ionic conductors is a critical challenge in the field of energy storage. In this study, a series of 1D anionic titanium-based covalent organic frameworks (COFs) containing abundant alkali metal ion migration sites, namely, COF-M-R (M = Li, Na, K; R = H, Me, Et), is constructed. The integration of negative TiO sites on 1D anionic COFs allows alkali metal cations to migrate directly through the channels.

Three-Dimensional Covalent Organic Frameworks Based on Linear and Trigonal Linkers for High-Performance HO Photosynthesis.

The design of three-dimensional covalent organic frameworks (3D COFs) using linear and trigonal linkers remains challenging due to the difficulty in achieving a specific non-planar spatial arrangement with low-connectivity building units. Here, we report the novel 3D COFs with linear and trigonal linkers, termed TMB-COFs, exhibiting srs topology. The steric hindrance provides an additional force to alter the torsion angles of peripheral triangular units, guiding the linear unit to connect with the trigonal unit into 3D srs frameworks, rather than the more commonly observed two-dimensional (2D) hcb structures.

Covalent Organic Frameworks for Electrocatalysis: Design, Applications, and Perspectives.

Covalent organic frameworks (COFs) are an innovative class of crystalline porous polymers composed of light elements such as C, N, O, etc., linked by covalent bonds. The distinctive properties of COFs, including designable building blocks, large specific surface area, tunable pore size, abundant active sites, and remarkable stability, have led their widespread applications in electrocatalysis.

Engineering a molecular ruthenium catalyst into three-dimensional metal covalent organic frameworks for efficient water oxidation.

The water oxidation reaction plays an important role in clean energy conversion, utilization, and storage, but mimicking the oxygen-evolving complex of photosystem II for designing active and stable water oxidation catalysts (WOCs) is still an appealing challenge. Here, we innovatively engineered a molecular ruthenium WOC as a metal complex building unit to construct a series of three-dimensional metal covalent organic frameworks (3D MCOFs) for realizing efficient oxidation catalysis. The resultant MCOFs possessed rare 3D interlocking structures with inclined interpenetration of two-dimensional covalent rhombic nets, and the Ru sites were periodically arranged in the crystalline porous frameworks.

A 3D Covalent Organic Framework with In-situ Formed Pd Nanoparticles for Efficient Electrochemical Oxygen Reduction.

Non-platinum noble metals are highly desirable for the development of highly active, stable oxygen reduction reaction (ORR) electrocatalysts for fuel cells and metal-air batteries. However, how to improve the utilization of non-platinum noble metals is an urgent issue. Herein, a highly efficient catalyst for ORR was prepared through homogeneous loading of Pd precursors by a domain-limited method in a three-dimensional covalent organic framework (COF) followed by pyrolysis.

SERS study of surface plasmon resonance induced carrier movement in Au@CuO core-shell nanoparticles.

A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@CuO nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with CuO shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS.

Thermochemical stabilities, electronic structures, and optical properties of C56X10 (X = H, F, and Cl) fullerene compounds.

Stimulated by the recent isolation and characterization of C₅₆Cl₁₀ chlorofullerene (Tan et al., J Am Chem Soc 2008, 130, 15240), we perform a systematic study on the geometrical structures, thermochemistry, and electronic and optical properties of C₅₆X₁₀ (X = H, F, and Cl) on the basis of density functional theory (DFT). Compared with pristine C₅₆, the equatorial carbon atoms in C₅₆X₁₀ are saturated by X atoms and change to sp³ hybridization to release the large local strains.

Electronic structures and nonlinear optical properties of highly deformed halofullerenes C(3v) C60F18 and D(3d) C60Cl30.

Electronic structures and nonlinear optical properties of two highly deformed halofullerenes C(3v) C(60)F(18) and D(3d) C(60)Cl(30) have been systematically studied by means of density functional theory. The large energy gaps (3.62 and 2.

Structural stability and electronic property of C68X4 (X=H, F, and Cl) fullerene compounds.

A systematic study on the geometrical structures and electronic properties of C(68)X(4) (X=H, F, and Cl) fullerene compounds has been carried out on the basis of density functional theory. In all classical C(68)X(4) isomers with two adjacent pentagons and one quasifullerene isomer [C(s):C(68)(f)] containing a heptagon in the framework, the C(s):0064 isomers are most favorable in energy. The addition reaction energies of C(68)X(4) (C(s):0064) are high exothermic, and C(68)F(4) is more thermodynamically accessible.

Search for the most stable Ca@C44 isomer: structural stability and electronic property investigations.

Stimulated by the mass spectroscopic observation of the metallofullerene Ca@C(44), we have performed a systematic investigation to search for the most stable isomer using HF/3-21G approximately LanL2DZ, HF/6-31+G(d), B3LYP/6-31+G(d), and MP2/6-31+G(d)//B3LYP/6-31+G(d) methods. The Ca@C(44) (D(2):53) isomer with eight adjacent pentagons in the fullerene framework is predicted to possess the lowest energy. The thermodynamics stability explorations of Ca@C(44) isomers at different temperatures show that Ca@C(44) (D(2):53) is the most thermodynamically stable in the temperature range of absolute zero to 4000 K.