Minghua Wang,Dan Guo,Bochong Wang,Jianyong Xiang,Kun Zhai,Tianyu Xue,Fusheng Wen,Yingchun Cheng,Congpu Mu
In this work, MIL-96 (Ga) was successfully synthesized by a microwave-assisted method and pyrolyzed at 700 o C to obtain Ga 2 O 3 /C (G-700) composites. After carbonization, Ga 2 O 3 nanoparticles were uniformly embedded in a porous carbon skeleton. The surface of MIL-96(Ga)-derived Ga 2 O 3 /C was used as a template for directional pyrrole polymerization. G-700@PPy composite materials were obtained by in-situ polymerization of pyrrole on the surface of G-700. A hierarchical interfacial structure was created with regulated dielectric properties. The effect of pyrrole doping content on the electromagnetic waves (EMWs) absorption properties of G-700@PPy composite materials was studied. The experimental result showed that the minimum reflection loss ( RL min ) value of G-700@PPy-3 composite materials reached -79.0 dB under a thin thickness of 1.58 mm, and the maximum effective absorption bandwidth (EAB) of 5.66 GHz was obtained under 1.78 mm. The results indicate that highly conductive PPy could significantly improve the impedance matching conditions and electromagnetic attenuation capacity of G-700 composite materials, which provided an important idea for optimizing the microwave absorption properties of low permittivity composites.
Yusen Chen,Shuzhao Zhang,Xiongcheng Duan,Jia Liu,Hengye Li,Meijie Wei,Wei Wang
The rapid and efficient removal of radioiodine from water is a challenging and meaningful task to safeguard human health. Herein, two calix[4]pyrrole-based polymers were prepared through Mannich reaction between nitrogen-rich 2,4,6-tri(piperazin-1-yl)-1,3,5-triazine (TPT) and two configurational isomers of tetra- meso resorcinol-functionalized calix[4]pyrrole (2α2β-CP and 4α-CP), referred as 2α2β-CP-TPT and 4α-CP-TPT, respectively. The nitrogen contents of 2α,2β-CP-TPT and 4α-CP-TPT were as high as 15.11 % and 14.84 %, respectively. Accompanied by the bowl-shaped calix[4]pyrroles, the CP-TPTs showed high vapor iodine uptake, especially 4.82 g/g for 4α-CP-TPT. More importantly, the CP-TPTs exhibited rapid adsorption kinetics for capture iodine from aqueous phase, with the 2α,2β-CP-TPT at 1 mg/mL level showing a k 2 value as high as 7.374 × 10 −3 g/(mg min). In addition, high iodine adsorption capacity for 2α,2β-CP-TPT and 4α-CP-TPT were achieved to be 1989.6 and 2812.6 mg/g from water, respectively. Even more impressive was the removal efficiency above 98 % in flow-through applications even at flow rate as high as 10 mL/min and in simulated seawater conditions. The CP-TPTs could also exhibit high dynamic iodine adsorption capacity from water as well as excellent stability and outstanding reusability. Adsorption mechanism study discovered the foundational role of the charge transfer interaction on the excellent adsorption performance of the CP-TPTs. All these features demonstrated promising application prospects of the CP-TPTs for iodine removal from water.
Harvesting electrical energy from the ubiquitous water cycle to power flexible electronic devices is receiving increasing attention. However, the development of moisture-driven generators with high and stable power output remains a significant challenge. Here, we design a photothermal evaporation-driven moisture generator (PEMG) that modifies a cotton fabric with in situ polymerized pyrrole by a polydopamine (PDA)-structured color film to form an asymmetric photothermal temperature gradient. The PDA asymmetric photothermal layer not only effectively addresses the issue of insufficient sustained power generation caused by water adsorption saturation but also mitigates the unstable moisture gradient resulting from excessive water evaporation. CF@PPy@PDA (purple) achieved an open-circuit voltage ( V oc ) of 0.74 V and a short-circuit current ( I sc ) of 0.72 mA under 60% relative humidity (RH) and 1-sun illumination, respectively. White LED bulbs emit a steady stream of light for more than 24 h. Moreover, the V oc of the PEMG (six units in series) reaches 1.18 V at an average solar intensity of 1000 W m −2 and 43% RH, while the V oc is 0.72 V at night (52% RH). Meanwhile, wearable systems designed with integrated PEMG units provide sufficient power supply for electronic devices under natural conditions.
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