To enhance mercury removal efficiency at low temperature in flue gas , UiO-66-NH 2 framework was functionalized using halogen group via a diazotization process. -NH 2 was successfully replaced by halogen groups, and diazotization process had little impact on the morphology and the structural information of UiO-66-NH 2 , indicated UiO-66-X (Cl, Br, I) had an excellently chemical stability. Hg 0 capture experiments indicated added iodine (I) functional group was the most effective compared with chlorine (Cl) and bromine (Br). UiO-66-I can reach nearly 100% Hg 0 removal efficiency at 25–150 ℃，and the difference was the duration time for high performance. Moreover, oxygen played an important role for Hg 0 removal, which could be activated by the halogen functional group and then reacted with Hg 0 , finally existed on the adsorbent in the form of UiO-66-X … Hg-O. Furthermore, adsorption kinetic analysis indicated mercury adsorption at surface active sites was the rate controlling step .
Lithium-selenium batteries (LSeBs) have attracted increasing attention due to their excellent electronic conductivity and high theoretical specific capacity. However, there are still difficult problems such as low utilization rate and fast capacity decay in the actual application process. Herein, a surface iodine modified three-dimensional (3D) nano hollow carbon fiber (I-NHCF) network is designed and synthesized as Se host (Se@I-NHCF) for highly stable LSeBs. The surface iodine species induce the formation of robust cathode electrolyte interface (CEI), thus preventing the transformation of amorphous selenium to low-activity crystalline selenium and enabling stable electrochemical performance. Moreover, the surface iodine species promote rapid charge transfer, enhancing the chemical reaction kinetics and improving the utilization of the active Se species. As a result, the Se@I-NHCF cathode exhibits superior specific capacity of 581.8 mAh g −1 with a high stability (0.0054% capacity decay per cycle) after 500 cycles at 1C, and an excellent rate performance of 567.6 mAh g −1 at 2C. This work addresses the problem of rapid capacity decay by the formation of uniform and robust CEI to conserve highly reactive amorphous Se species, improve Se utilization, and achieve ultra-stable Li-Se batteries with high energy and long cycle life.
Jiajia Long,Yuting Qian,Wenrou Tian,Najun Li,Dongyun Chen,Qingfeng Xu,Hua Li,Jianmei Lu
The insufficient active sites, low separation efficiency of free carriers and poor capacity to generate active free radicals are limitations of asymmetrical BiFeO 3 in piezocatalysis. To address these issues, BiFeO 3 hollow nanospheres with exposed abundant catalytic active sites were fabricated via a solvothermal method for the first time. In addition, surface iodine-grafting was introduced, resulting in a local electric field and the conduction band potential of BiFeO 3 closer to the O 2 /·O 2 – redox potential (-0.33 eV). It facilitated charge transmission and active species generation to remove bisphenol A under ultrasonic vibration. Thus, the iodine-grafted BiFeO 3 hollow nanospheres could completely degrade 20 mL bisphenol A (10 ppm) within 60 min with a relatively fast rate constant of 0.153 min −1 , which was 4.5 times higher than that of un-grafted BiFeO 3 . This work provides a feasible approach to construct efficient piezocatalysts for industrial wastewater purification.
危险品化学品经营许可证（带存储）