Additive Mixing of Emissive Ligands in Covalent Organic Frameworks for White Light Emission.

Emissive covalent organic frameworks (COFs) are a promising class of crystalline materials that have demonstrated applications for sensing and light-emitting diodes. However, white light emission from a single COF has not been achieved yet as it requires multicomponent organic chromophores that simultaneously emit blue, green, and red light. In this work, we report the successful synthesis of a single COF with efficient white light emission by utilizing tunable emission properties of 2,1,3-benzothiadazole after incorporating different functional groups on its core structure, which results in the formation of three ligands, i.

Cu Promoted the Dynamic Evolution of Ni-Based Catalysts for Polyethylene Terephthalate Plastic Upcycling.

Upcycling plastic wastes into value-added chemicals is a promising approach to put end-of-life plastic wastes back into their ecocycle. As one of the polyesters that is used daily, polyethylene terephthalate (PET) plastic waste is employed here as the model substrate. Herein, a nickel (Ni)-based catalyst was prepared via electrochemically depositing copper (Cu) species on Ni foam (NiCu/NF).

Dominant Role of Hole Transport Pathway in Achieving Record High Photoconductivity in Two-Dimensional Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) with mobile charges have attracted significant attention due to their potential applications in photoelectric devices, chemical resistance sensors, and catalysis. However, fundamental understanding of the charge transport pathway within the framework and the key properties that determine the performance of conductive MOFs in photoelectric devices remain underexplored. Herein, we report the mechanisms of photoinduced charge transport and electron dynamics in the conductive 2D M-HHTP (M=Cu, Zn or Cu/Zn mixed; HHTP=2,3,6,7,10,11-hexahydroxytriphenylene) MOFs and their correlation with photoconductivity using the combination of time-resolved terahertz spectroscopy, optical transient absorption spectroscopy, X-ray transient absorption spectroscopy, and density functional theory (DFT) calculations.

Engineering Band Gap and Photoconduction in Semiconducting Metal Organic Frameworks: Metal Node Effect.

We report a systematic study on the correlation of the metal nodes in M-THQ conducting MOFs (M = Fe, Ni, Cu, and Zn; THQ = tetra-hydroxybenzoquinone) with their structure, photophysical property, and photoconductivity. We found that the structural preference in these MOFs is controlled by metal node identity where Cu prefers a square planar coordination which leads to a 2D Kagome-type structure. Fe, Ni, and Zn prefer an octahedral sphere which leads to a 3D structure.

Quantum dot gels as efficient and unique photocatalysts for organic synthesis.

Here we report CdS quantum dot (QD) gels as highly efficient and unique photocatalysts for organic synthesis. We found that the photocatalytic activity of CdS QD gel was superior to phosphine oxide- and thiolate-capped CdS QDs for dehalogenation and α-amine arylation reactions because of the high accessibility of its surface sites to the substrates. In addition, we discovered the unique reactivity of CdS QD gel for ring-opening during α-amine arylation of tetrahydroisoquinoline the reductive cleavage of C-N bonds.

Symmetry-Guided Synthesis of -Bicarbazole and Porphyrin-Based Mixed-Ligand Metal-Organic Frameworks: Light Harvesting and Energy Transfer.

In the past decades, many attempts have been made to mimic the energy transfer (EnT) in photosynthesis, a key process occurring in nature that is of fundamental significance in solar fuels and sustainable energy. Metal-organic frameworks (MOFs), an emerging class of porous crystalline materials self-assembled from organic linkers and metal or metal cluster nodes, offer an ideal platform for the exploration of directional EnT phenomena. However, placing energy donor and acceptor moieties within the same framework with an atomistic precision appears to be a major synthesis challenge.

Direct Evidence of Photoinduced Charge Transport Mechanism in 2D Conductive Metal Organic Frameworks.

Conductive metal organic frameworks (MOFs) represent a promising class of porous crystalline materials that have demonstrated potential in photo-electronics and photocatalytic applications. However, the lack of fundamental understanding on charge transport (CT) mechanism as well as the correlation of CT mechanism with their structure hampered their further development. Herein, we report the direct evidence of CT mechanism in 2D Cu-THQ MOFs and the correlation of temporal and spatial behaviors of charge carriers with their photoconductivity by combining three advanced spectroscopic methods, including time resolved optical and X-ray absorption spectroscopy and terahertz spectroscopy.

Unravelling a long-lived ligand-to-metal cluster charge transfer state in Ce-TCPP metal organic frameworks.

Metal organic frameworks (MOFs) have emerged as promising photocatalytic materials for solar energy conversion. However, a fundamental understanding of light harvesting and charge separation (CS) dynamics in MOFs remains underexplored, yet they are key factors that determine the efficiency of photocatalysis. Herein, we report the design and CS dynamics of the Ce-TCPP MOF using ultrafast spectroscopic methods.