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Although all-inorganic lead halide perovskite nanocrystals (NCs) have attracted great attention, the intrinsic toxicity of lead remains to be resolved. Doped CsBr NCs have recently proved to be a new promising candidate of lead-free NCs, but the low photoluminescence quantum yield (PLQY) and the difficulty in the fine modulation of chrominance are still the current challenges. Herein, environment-friendly Cu doped CsBr (Cu:CsBr) NCs were synthesized with good stability and high PLQY (∼38.8%) by using a facile one-pot colloidal synthesis approach. Moreover, for the first time, Mn was introduced into the Cu:CsBr NCs, resulting in dual-emission from Cu and Mn dopants. By controlling the doping amounts of Mn, the co-doped CsBr NCs with flexibly controlled two emission peak intensities and chrominance could be realized. The current co-doping method can not only realize fine modulation of chrominance but also avoid the instability induced by mixed halide. Finally, as-synthesized NCs can be employed as an efficient color conversion layer for fabricating phosphor-converted LEDs. [ABSTRACT FROM AUTHOR]

The development of asymmetric supercapacitors (ASCs) with high power and energy density is greatly restricted by the low capacitance of the anode materials. V2O5 is a promising anode material with high theoretical capacity, but its low conductivity and high dissolution are not conducive to applications in energy storage. Herein, oxygen-vacancy PEDOT/V2O5 ultrathin nanosheets with a thickness of about 4.4 nm are fabricated by the oxidative polymerization of EDOT monomers on V2O5 nanosheets in the absence of other oxidants. The results of XPS and EPR confirm that the polymerization of PEDOT increases the oxygen vacancy concentration of V2O5. The PEDOT/V2O5 nanosheets exhibit a specific capacitance of 406 F g−1 at 2 mV s−1 and excellent cyclic stability in the mixed organic electrolyte of dimethyl carbonate and ethylene carbonate. The energy density of ASCs composed of PEDOT/V2O5 as the anode and activated carbon as the cathode reaches 65 W h kg−1 at a power density of 1490 W kg−1. This means that PEDOT/V2O5 has enormous potential in high-energy storage. [ABSTRACT FROM AUTHOR]

Through-bond conjugated rod-like molecules are the major frameworks for traditional conjugated polymers, while through-space conjugated groups are rarely utilized in the construction of conjugated polymer backbones. Herein, we report a series of oligomers consisting of thiophene/EDOT and naphthalene featuring through-bond or through-space conjugation. The structure–property relationships and electropolymerized performances of the oligomers and the effect of through-space conjugation on the properties of polymers are fully investigated. The crystal structures and theoretical calculations show that through-bond and through-space conjugations are integrated into one single molecule, allowing for two transport channels in conjugated polymers, which is beneficial for improving the redox activity and stability. The multichannel transport by integrating through-bond and through-space conjugations could be an effective strategy for robust conjugated polymers. [ABSTRACT FROM AUTHOR]

Fluorination of conjugated polymers has been explored as a viable strategy for enhancing the overall performance of corresponding polymers. In this work, two trifluoromethylated polyindoles (5-PFMIn and 6-PFMIn) are synthesized via simple electropolymerization and applied as energy storage materials for supercapacitors. Spectroscopic, morphological, thermal stability, and electrochemical analyses of trifluoromethylated polyindoles and their non-fluorinated counterparts (5-PMIn and 6-PMIn) are performed to reveal the significant effect of the trifluoromethyl group on the properties of polymers. Compared with non-fluorinated counterparts, 5-PFMIn and 6-PFMIn show rougher morphologies and higher thermal stabilities, and more interestingly, the fluorination of polyindoles results in substantial improvement of their electrochemical behavior. The specific capacitances of 5-PFMIn and 6-PFMIn are found to be 269 F g−1 and 296 F g−1 at 10 A g−1, respectively with excellent cycling stability of about 90% after 5000 cycles, which are superior to those of their counterparts, 5-PMIn (75 F g−1, 73%) and 6-PMIn (178 F g−1, 70%). The promising trifluoromethylated polyindoles demonstrate high potential for electrochemical capacitor application. [ABSTRACT FROM AUTHOR]

Two electrochromic polymers based on thiophene–benzene derivatives were prepared using an electrochemical method and exhibited multiple separate redox couples due to the introduction of side chains. The energy storage states of electrochromic supercapacitors based on the resulting polymers could be monitored by their appearance colour. [ABSTRACT FROM AUTHOR]

Owing to their excellent fluorescence properties and molecular wire signal amplification effect, water-soluble conjugated oligo-/polymer-based fluorescent sensors have been used for the detection of various metal ions, some of which have already been used in real applications in aqueous environments and biological systems. Herein, we synthesize water-soluble oligo(1-pyrenesulfonic acid) by one-step electropolymerization in boron trifluoride diethyl etherate (BFEE). This oligomer is demonstrated to be an excellent blue light-emitter with a high fluorescence quantum yield of approximately 0.68 in deionized water. We further find that oligo(1-pyrenesulfonic acid) can be employed to effectively detect Fe3+ in aqueous solution due to the aggregation fluorescence quenching of its oligomer chains. Minute sensing analytical results indicate that the oligomer displays good selectivity and a low detection limit (1.00 × 10−7 M), which are better than those of its monomer 1-pyrenesulfonic acid. Moreover, the fluorescence quenching of the oligomer can be recovered by introducing phosphates with outstanding reversibility (97% of its original intensity). With these results, electrosynthesized oligo(1-pyrenesulfonic acid) will be a good candidate for the determination of Fe3+ in aqueous solution. [ABSTRACT FROM AUTHOR]

Freestanding flexible capacitive materials are ideal for use in bendable electronic devices. However, it is difficult to prepare pure PEDOT films in a freestanding state by chemical and electrochemical methods. Here, we used a simple strategy of introducing alkoxy, ether, ester, and amide chains for bridging two EDOT units to form precursors, which could then be electrodeposited readily to produce freestanding and flexible films. The precursor with the amide group was suitable for obtaining higher-quality films with improved thermal stability, mechanical properties, and capacitive performance. In addition, the asymmetric PBEDTA//PEDOT capacitors exhibited a capacitance retention rate of 98.5% after 5000 cycles, which is higher than those of PBEDTH//PEDOT (92.7%), PBEDTG//PEDOT (80.5%), and PBEDTE//PEDOT (86.8%) capacitors. This result indicates that the polymer films and, in particular, the PBEDTA films, are suitable for use in flexible supercapacitors. [ABSTRACT FROM AUTHOR]

Conjugated polymers containing selenophene have received attention due to their unique properties and promising application in organic electronics. Herein, to further improve the optoelectronic properties, two typical selenophenes containing [1,2,5]thiadiazolo[3,4-c]pyridine (PT)/[1,2,5]selenadiazolo[3,4-c]pyridine (PS) were synthesized by a donor–acceptor strategy and electropolymerized to form the donor–acceptor–donor polymers. The two precursors exhibited yellow and red emission characteristics with high quantum yields (∼0.48); the value was far greater than those for previously reported selenophenes. Furthermore, electrochromic studies demonstrated that the obtained polymers have superior coloration efficiencies (168 cm−2 C−1) than thiophene based analogues and fast response times (1.6 s). [ABSTRACT FROM AUTHOR]

In this work, poly(N-methyl-3,4-dihydrothieno[3,4-b][1,4]oxazine) (PMDTO), a new nitrogen poly(3,4-ethylendioxythiophene) (PEDOT) analogue, was synthesized by an electrochemical deposition method, and the capacitive properties of PMDTO were investigated and compared with those of PEDOT. The structure and morphology of PMDTO were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. The pseudocapacitive properties of the as-prepared PMDTO electrodes have been examined by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) measurements and electrochemical impedance spectroscopy (EIS) in 0.1 mol L−1 CH3CN–Bu4NBF4 electrolyte solution. The as-prepared PMDTO electrode showed a high specific capacitance of 154.3 F g−1 at a discharge current density of 3 A g−1 and exhibited cycling stability with the maximal capacitance retention of nearly 71% after 500 cycles at a high current density of 10 A g−1. Additionally, the asymmetrical supercapacitor based on PMDTO and PEDOT electrodes exhibited a maximum specific capacitance of 63.5 F g−1 and an energy density of 12.7 W h kg−1 at a power density of 0.59 kW kg−1. These results implied that the PMDTO electrode can be used as a potential electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

Two novel EDOT end-capped monomers, namely, 2,8-di-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl-dibenzothiophene (DBT-EDOT), and 2,8-di-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl-dibenzofuran (DBF-EDOT), were synthesised via Stille coupling and electropolymerised to form conjugated polymers P(DBT-EDOT) and P(DBF-EDOT). The monomers exhibited blue-light-emitting characteristics, and DFT calculations revealed band gap values of 4.20 eV for DBT-EDOT and 4.34 eV for DBF-EDOT, while those of the corresponding polymers were brought down to 2.46 eV for P(DBT-EDOT) and 2.58 eV for P(DBF-EDOT), respectively. Moreover, both of the polymers displayed good electrochromic properties with colour switching between yellow in the reduced state and purple in the oxidised state. Structure characterisation and properties of monomers and as-formed polymers using FTIR spectroscopy, UV-vis spectroscopy, surface morphology, fluorescence spectroscopy, electrochemistry, and spectroelectrochemistry, together with structure–property relationships, were systematically investigated and comprehensively discussed. [ABSTRACT FROM AUTHOR]