We report a simple metal ion-catechol coordination strategy to coat ruthenium-catechol polymer complex (TAC-Ru) on the surface of carbon nanotubes (CNT) to form a core-shell structure (abbreviated as CNT@TAC-Ru). This is achieved by firstly polymerizing catechol and boronic acid monomers on the surface of CNT to form a boronate ester polymer (BP) shell. Then, Ru3+is used to etch the BP shell, and cleave the dynamic boronate ester bond, leading to the formation of a CNT@ruthenium-catechol coordination complex based on the coordinative efficiency of the catechol group. The electrocatalytic property of the CNT@TAC-Ru composite can be activated through electrochemical cycling treatment. The as-activated CNT@TAC-Ru exhibits evidently improved hydrogen evolution reaction (HER) performance with an overpotential of 10 mV in 1.0 M KOH at a current density of 10 mA cm-2, which is better than that of commercial Pt/C (32 mV). And the long-term stability is also desirable. This work provides a pyrolysis-free method to form metal-polymer-carbon composite with high HER performance under the alkaline condition.
BiOCl has been actively explored as a promising material for photodetectors (PDs), but inefficient charge separation and narrow response spectral range limit the further development of BiOCl-based PDs. Herein, we show that coating BiOCl with a boronate polymer (BP) shell may provide a simple route to overcome the above limitations. The migration of Bi3+ from BiOCl to BP changes the energy level and enhances the light absorption of BP shell. Violent coordination at the core-shell interface, as well as Bi3+ migration induces the generation of Bi3+-O·-Bi3+ defects. Also, BP shell can reduce the darkcurrent of BiOCl@BPs PDs. The optimized PD assembled with BiOCl@BP1.9 (the subscript represents the shell thickness) shows fast photoresponse (rise time: 32, decay time: 52 ms, respectively), high on/off ratio, and responsivity of 119.77 μA/W under 365 nm light at 15 V. Moreover, BiOCl@BP PDs exhibit a gradually broadened spectral response range with the increase of BP shell thickness and show much higher photodetection performances. For example, under 940 nm light stimulation, the optimized PD (BiOCl@BP20.1) exhibits a high responsivity of 22.18 μA/W, 28 times that of BP PD. Our findings may provide a guideline for the design of high-performance PDs based on the precise construction of polymer-inorganic heterostructures.
In order to easily achieve the multifunctionality of epoxy resin, this paper designs and synthesizes a ternary hybrid copolymer containing POSS/DOPO/F. This method not only facile combines POSS with DOPO, but also introduces F element to further reduce the surface energy of epoxy composite materials. Research has found that the POSS/DOPO/F ternary hybrid copolymer can achieve a UL-94 flame retardant rating of V-0 and a limit oxygen index of 32% for epoxy composites at a content of only 5 wt%, which is 23.1% higher than pure epoxy. The residual carbon after combustion is denser and the carbonization rate is higher. Furthermore, we conducted an in-depth analysis of the flame retardant mechanism of POSS/DOPO/F ternary hybrid copolymer epoxy composites using TGA-FTIR technology and EDS. In addition, the introduction of ternary hybrid polymers effectively improves the mechanical properties of epoxy composite materials and significantly reduces the surface energy of the composite materials.
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