: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Rapidly increasing atmospheric CO2 concentrations threaten human society, the natural environment, and the synergy between the two. In order to ameliorate the CO2 problem, carbon capture and conversion techniques have been proposed. Metal–organic framework (MOF)-based materials, a relatively new class of porous materials with unique structural features, high surface areas, chemical tunability and stability, have been extensively studied with respect to their applicability to such techniques. Recently, it has become apparent that the CO2 capture capabilities of MOF-based materials significantly boost their potential toward CO2 conversion. Furthermore, MOF-based materials’ well-defined structures greatly facilitate the understanding of structure–property relationships and their roles in CO2 capture and conversion. In this review, we provide a comprehensive account of significant progress in the design and synthesis of MOF-based materials, including MOFs, MOF composites and MOF derivatives, and their application to carbon capture and conversion. Special emphases on the relationships between CO2 capture capacities of MOF-based materials and their catalytic CO2 conversion performances are discussed.

Carbon capture and conversion using metal–organic frameworks and MOF-based materials

Advanced oxidation process-mediated removal of pharmaceuticals from water: A review.

More than 95% (in volume) of all of today’s chemical products are manufactured through catalytic processes, making research into more efficient catalytic materials a thrilling and very dynamic rese...

Metal–Organic Frameworks in Heterogeneous Catalysis: Recent Progress, New Trends, and Future Perspectives

Covalent organic frameworks (COFs) as an emerging class of crystalline porous materials have received much attention due to their tunable porosity, modifiable skeletons, and atomically precise structures. Besides, COFs can provide multiple high-rate charge carrier transport (electron, hole, and ion) pathways, including conjugated skeletons, overlapped π electron clouds among the stacked layers, and open channels with a variable chemical environment. Therefore, they have shown great potential in electrochemical energy storage (EES) and conversion (EEC). However, in bulk COFs, the defects always impede charge carrier conduction, and the difficulties in reaching deep-buried active sites by either electrons or ions lead to limited performance. To overcome these obstacles, numerous research studies have been carried out to obtain COF nanosheets (NSs). This review first describes the preparation strategies of COF NSs via bottom-up and top-down approaches. Then, the applications of bulk COFs and COF NSs in EES and EEC are summarized, such as in batteries, supercapacitors, and fuel cells. Finally, key challenges and future directions in these areas are discussed.

Bulk COFs and COF nanosheets for electrochemical energy storage and conversion

Recent Development of Metallic (1T) Phase of Molybdenum Disulfide for Energy Conversion and Storage

Exfoliated Triazine-Based Covalent Organic Nanosheets with Multielectron Redox for High-Performance Lithium Organic Batteries

MOFs-Based Heterogeneous Catalysts: New Opportunities for Energy-Related CO2 Conversion

In this research, bulk graphitic carbon nitride (g-C3 N4 ) is exfoliated and transferred to the carbon nitride nanosheets (CNNSs), which are then coupled with MIL-88B(Fe) to form the hybrid. From the results of the powder X-ray diffraction, scanning electronic microscopy and thermogravimetric analysis, it is found that the doping of CNNSs on the surface of MIL-88(Fe) could maintain the basic structure of MIL-88B(Fe), and the smaller dimension of CNNSs might influence the crystallization process of metal-organic frameworks (MOFs) compared to bulk g-C3 N4 . Besides, the effects of the CNNSs incorporation on photocatalysis are also investigated. Through the photoluminescence spectra, electrochemical measurements, and photocatalytic experiments, the hybrid containing 6% CNNSs is certified to possess the highest catalytic activity to degrade methylene blue and reduce Cr(VI) under visible light. The improvement of the photocatalytic performance can be attributed to the matched energy level which favors the formation of the heterojunctions. Besides, it promotes the charge migration such that the contact between MOFs and CNNSs is more intimate, which can be inferred from the electronic microscopy images. Finally, a possible photocatalytic mechanism is put forward by the relative calculation and the employment of the scavengers to trap the active species.

The Influence of Carbon Nitride Nanosheets Doping on the Crystalline Formation of MIL-88B(Fe) and the Photocatalytic Activities.

Layered material MoS2 is widely applied as a promising anode for lithium-ion batteries (LIBs). Herein, a scalable and facile dopamine-assisted hydrothermal technique for the preparation of strongly coupled MoS2 nanosheets and nitrogen-doped graphene (MoS2 /N-G) composite is developed. In this composite, the interconnected MoS2 nanosheets are well wrapped onto the surface of graphene, forming a unique veil-like architecture. Experimental results indicate that dopamine plays multiple roles in the synthesis: a binding agent to anchor and uniformly disperse MoS2 nanosheets, a morphology promoter, and the precursor for in situ nitrogen doping during the self-polymerization process. Density functional theory calculations further reveal that a strong interaction exists at the interface of MoS2 nanosheets and nitrogen-doped graphene, which facilitates the charge transfer in the hybrid system. When used as the anode for LIBs, the resulting MoS2 /N-G composite electrode exhibits much higher and more stable Li-ion storage capacity (e.g., 1102 mAh g-1 at 100 mA g-1 ) than that of MoS2 /G electrode without employing the dopamine linker. Significantly, it is also identified that the thin MoS2 nanosheets display outstanding high-rate capability due to surface-dominated pseudocapacitance contribution.

Zhendong Lei

Papers

Recent Development of Metallic (1T) Phase of Molybdenum Disulfide for Energy Conversion and Storage

Exfoliated Triazine-Based Covalent Organic Nanosheets with Multielectron Redox for High-Performance Lithium Organic Batteries

MOFs-Based Heterogeneous Catalysts: New Opportunities for Energy-Related CO2 Conversion

The Influence of Carbon Nitride Nanosheets Doping on the Crystalline Formation of MIL-88B(Fe) and the Photocatalytic Activities.

Strong Coupling of MoS2 Nanosheets and Nitrogen-Doped Graphene for High-Performance Pseudocapacitance Lithium Storage