Redox-Active Triphenylamine-Triazine Covalent Organic Framework: A High Surface Area Microporous Material for Electrochromism and Electrofluorochromism.

Porous covalent organic frameworks (COFs) offer significant advantages in electrochromic (EC) applications due to their high surface area and porosity, which facilitate faradaic redox-mediated diffusion-controlled processes. However, COFs remain underexplored as EC materials due to challenges such as limited solubility and poor film-forming ability. In this study, we synthesized a redox-active triphenylamine-containing COF (TPA-TCIF) on ITO glass via a solvothermal method tailored for electrochromism and electrofluorochromism.

Harnessing Biomolecule-Infused 2D Multi-layered Luminescent Zn(II) Coordination Polymer for Electrochemical Energy Storage.

Selecting the right functional linkers and metal centers is crucial for creating multifunctional crystalline coordination polymers, which show promise in energy storage applications. Herein, a new two-dimensional Zn(II)-based CP, named , has been synthesized using solvothermal methods with 2-amino terephthalic acid (2ATA) and the biomolecule purine as key building blocks. Purine, which is relatively unexplored in CP synthesis, plays a crucial role in the distinct properties of CPs.

A Highly Robust and Conducting Ultramicroporous 3D Fe(II)-Based Metal-Organic Framework for Efficient Energy Storage.

Exploitation of metal-organic framework (MOF) materials as active electrodes for energy storage or conversion is reasonably challenging owing to their poor robustness against various acidic/basic conditions and conventionally low electric conductivity. Keeping this in perspective, herein, a 3D ultramicroporous triazolate Fe-MOF (abbreviated as Fe-MET) is judiciously employed using cheap and commercially available starting materials. Fe-MET possesses ultra-stability against various chemical environments (pH-1 to pH-14 with varied organic solvents) and is highly electrically conductive (σ = 0.

Electro-Oxidation Reaction of Methanol over LaSrNi(Mn/Fe/Co)O Ruddlesden-Popper Oxides.

Solution combustion-synthesized Ruddlesden-Popper oxides LaSrNi(Mn/Fe/Co)O were explored for the methanol electro-oxidation reaction. With optimal doping of Sr in the A site and Co in the B site, Ni with t configuration in LaSrNiCoO exhibited a tetragonal distortion with compression in axial bonds and elongation in equatorial bonds. This structural modification fostered an augmented overlap of orbitals with axial O 2p orbitals, leading to a heightened density of states at the Fermi level.

Co-containing metal-organic framework for high-performance asymmetric supercapacitors with functionalized reduced graphene oxide.

Nowadays, supercapacitors are the most coveted eco-friendly and sustainable next-generation energy storage devices. In this regard, developing supercapacitors with high energy density and power density has always been a challenge for researchers. Herein, we have exploited an electroactive Co-containing metal-organic framework (Co-MOF) using cheap and commercially available starting materials under refluxing conditions and explored its energy storage properties in three- and two-electrode methods.

Side-Chain Modification in Conjugated Polymer Frameworks for the Electrocatalytic Oxygen Evolution Reaction.

Conjugated polymer frameworks (CPFs) have recently sparked tremendous research interest due to their broad potentials in various frontline application areas such as photocatalysis, sensing, gas storage, energy storage, etc. These framework materials, without sidechains or functional groups on their backbone, are generally insoluble in common organic solvents and less solution processable for further device applications. There are few reports on metal-free electrocatalysis, especially oxygen evolution reaction (OER) using CPF.

A terpyridine based hydrogel system for reversible transmissive-to-dark electrochromism and bright-to-quenched electrofluorochromism.

A carboxylic acid-containing terpyridine-based hydrogelator (TPPCA) is synthesized to afford a self-assembly induced TPPCA hydrogel, which was used as an all-in-one electrochrome in electrochromic devices (ECDs) to demonstrate reversible transparent-to-black electrochromism with fast darkening and bleaching time of 8.3 s and 9.5 s, respectively, high photopic coloration efficiency of 65.

Electrochromic and photochromic behaviour in a single metal-organic framework containing a redox-active linker.

A Zr-based metal organic framework with naphthalene diimide teracarboxylate linkers is reported for its dual electrochromic and photochromic behavior. MOF crystals display reversible yellow to green photochromism upon exposure to visible light and colourless to dark-brown reversible electrochromism on applying a potential of 0 to -2.5 V.

Targeted Bioimaging of Cancer Cells Using Free Folic Acid-Sensitive Molybdenum Disulfide Quantum Dots through Fluorescence "Turn-Off".

In the present study, a proficient way for targeted bioimaging of folate receptor (FR)-positive cancer cells using free folic acid (FA)- and MoS QD-based nanoprobes is discussed along with its advantages over the preparation of orthodox direct FA-nanoprobe bioconjugates for the imaging. The water-soluble MoS QDs of size 4-5 nm with cysteine functionalization are synthesized by a simplistic bottom-up hydrothermal method. The as-prepared MoS QDs exhibit the blue emission with the highest emission intensity at 444 nm upon excitation of 370 nm.

Transmissive to blackish-green NIR electrochromism in a Co(II)-based interfacial co-ordination thin film.

Herein, a Co(ii)-based metallo-polymer (Co-tpy-L) with a three armed non-conjugated terpyridine ligand is synthesized using solvent-solvent interfacial polymerization. The thin film exhibits durable transmissive-to-blackish green electrochromism, selectively covering both the visible and NIR regions with a moderate voltage range of -1.4 to 0 V.

Metal-Immobilized Micellar Aggregates of a Block Copolymer from a Mixed Solvent for a SERS-Active Sensing Substrate and Versatile Dip Catalysis.

Here, we have reported micellar aggregations of an amphiphilic block copolymer in mixed solvent and their subsequent use as a template for the fabrication of a very dense, tunable metal nanoparticle-decorated surface for SERS and flexible dip catalysis applications. A silver nanoparticle-immobilized layer on silicon substrates shows excellent SERS (surface-enhanced Raman scattering)-based sensing performance for model analyte rhodamine B up to 10 M concentration with a well-defined calibration curve. Furthermore, a facile approach to the preparation of metal NP-immobilized BCP membranes as efficient dip catalyst for two model reactions (the reduction of nitrophenol and the Suzuki-Miyaura reaction of iodobenzene or 2,7-diiodofluorene with phenyl boronic acid) is also demonstrated.

Interfacial Coordination Nanosheet Based on Nonconjugated Three-Arm Terpyridine: A Highly Color-Efficient Electrochromic Material to Converge Fast Switching with Long Optical Memory.

An electrochromic (EC) hyperbranched coordination nanosheet (CONASH) comprising a three-arm terpyridine (3tpy)-based ligand and Fe(II) ion has been synthesized by interfacial complexation at the liquid-liquid interface. The film can be easily deposited on the desired substrate such as indium tin oxide (ITO) glass. Characterization of CONASH deposited on ITO by microscopic methods reveals the homogeneous nanosheet film with an ∼350 nm thickness after 48 h of reaction.

Structure-Sensitive Electrocatalytic Reduction of CO to Methanol over Carbon-Supported Intermetallic PtZn Nano-Alloys.

The electrochemical reduction of CO (CORR) to produce valuable synthetic fuel like CHOH not only mitigates the accumulated greenhouse gas from the environment but is also a promising direction toward attenuating our continuous reliance on fossil fuels. However, CORR to yield CHOH suffers because of large overpotential, competitive H evolution reaction (HER), and poor product selectivity. In this regard, intermetallic alloy catalysts open up a wide possibility of fine-tuning the electronic property and attain appropriate structures that facilitate selective CORR.

Enhanced Photoinduced Electrocatalytic Oxidation of Methanol Using Pt Nanoparticle-Decorated TiO-Polyaniline Ternary Nanofibers.

Herein, perylene-3,4,9,10-tetracarboxylic acid-doped polyaniline (PTP) nanofibers with/without photoreactive anatase TiO (TiO-PTP and PTP, respectively) have been successively synthesized and subsequently decorated by Pt nanoparticles (Pt NPs) to prepare Pt-PTP and Pt-TiO-PTP composites. High-resolution transmission electron microscopy confirms the presence of ∼3 nm spherical-shaped Pt NPs on both the composites along with TiO on Pt-TiO-PTP. Pt loading on the composites is deliberately kept similar to compare the methanol electro-oxidation in the two composites.

Probing the photo- and electro-catalytic degradation mechanism of methylene blue dye over ZIF-derived ZnO.

Due to the severe water pollution from effluent dyes, the need of the hour is to find a suitable dye degradation technology, and appropriate catalyst materials. Semiconducting ZnO was produced by pyrolysis of ZIF-8 template. The materials were well characterized with in situ and ex situ XRD and TGA, FE-SEM, HRTEM, UV-DRS, PL, and FRET.

Determination of band edges and their influences on photocatalytic reduction of nitrobenzene by bulk and exfoliated g-CN.

Thermally and chemically exfoliated metal-free semiconducting g-C3N4 are synthesized from bulk g-C3N4. Thorough characterization of the synthesized materials is performed with the help of XRD, FTIR, FE-SEM, PL, surface area analysis and DRS to probe differences in structural, morphological and optical properties between thermally and chemically exfoliated g-C3N4. The synthesized materials are exposed to light for photocatalytic reduction of nitrobenzene.

Modulation of a coordination structure in a europium(iii)-based metallo-supramolecular polymer for high proton conduction.

Developing high proton conducting solid materials is significant in the field of fuel cells. A europium(iii)-based metallo-supramolecular polymer with uncoordinated carboxylic acids (PolyEu-H) was successfully synthesized by modifying the synthesis conditions. The proton conductivity was enhanced with increasing the relative humidity (RH) from 30 to 95% RH.

Electrochromic Os(II)-Based Metallo-Supramolecular Polymers.

This work presents the preparation of a series of novel Os(II)-based metallo-supramolecular polymers (polyOss: linear polyOsL1 and hyperbranched polyOsL1 L2 ) that show a broad absorption spanning 312 to 677 nm and a low Os(II)/(III) redox potential of 0.94 V. The electrochromic properties of a polyOs film cast on an ITO substrate is investigated.

One-Dimensional Anhydrous Proton Conducting Channel Formation at High Temperature in a Pt(II)-Based Metallo-Supramolecular Polymer and Imidazole System.

One dimensional (1D) Pt(II)-based metallo-supramolecular polymer with carboxylic acids (polyPtC) was synthesized using a new asymmetrical ditopic ligand with a pyridine moiety bearing two carboxylic acids. The carboxylic acids in the polymer successfully served as apohosts for imidazole loaded in the polymer interlayer scaffold to generate highly ordered 1D imidazole channels through the metallo-supramolecular polymer chains. The 1D structure of imidazole loaded polymer (polyPtC-Im) was analyzed in detail by thermogravimetric analysis, powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible and photoluminescence spectroscopic measurements.

Proton Conductive Nanosheets Formed by Alignment of Metallo-Supramolecular Polymers.

Linear Fe(II)-based metallo-supramolecular polymer chains were precisely aligned by the simple replacement of the counteranion with an N,N'-bis(4-benzosulfonic acid)perylene-3,4,9,10-tetracarboxylbisimide (PSA) dianion, which linked the polymer chains strongly. A parallel alignment of the polymer chains promoted by the PSA dianions yielded nanosheets formation. The nanosheets' structure was analyzed with FESEM, HRTEM, UV-vis, and XRD in detail.

Platinum(II)-Based Metallo-Supramolecular Polymer with Controlled Unidirectional Dipoles for Tunable Rectification.

A platinum(II)-based, luminescent, metallo-supramolecular polymer (PolyPtL1) having an inherent dipole moment was synthesized via complexation of Pt(II) ions with an asymmetric ligand L1, containing terpyridyl and pyridyl moieties. The synthesized ligand and polymer were well characterized by various NMR techniques, optical spectroscopy, and cyclic voltammetry studies. The morphological study by atomic force microscopy revealed the individual and assembled polymer chains of 1-4 nm height.

Vice versa donor acceptor fluorene-ferrocene alternate copolymer: a twisted ribbon for electrical switching.

Two donor-acceptor type copolymers (PFFC-1 and PFFC-2) containing ferrocene and fluorene moieties have been successfully synthesized to evaluate the redox triggered optical and electronic properties. Interestingly, PFFC-1 shows a twisted ribbon-like morphology at the liquid interface and switches to a micellar structure on oxidation.