The synthesis of a novel conjugated microporous polymer and application on photocatalytic removal of uranium(Ⅵ) from wastewater under visible light

Amide Linkages in Pyrene-Based Covalent Organic Frameworks toward Efficient Photocatalytic Reduction of Uranyl

“…Imine and amide COF TFPPy–DP were applied to photocatalysis reduction of U­(VI) under 40 W LED lamps (460 nm), various kinds of organic compounds (isopropyl alcohol, lactic acid, and ascorbic acid) were tested as sacrificial agents for trapping photogenerated holes, , as shown in Figure a, either imine or amide COFs, the concentration of U­(VI) did not change in the absence of additional sacrificial agent, indicating that U­(VI) was neither catalyzed, reduced, nor adsorbed by imine or amide COFs. In the presence of 0.5% lactic acid, the removal percentages of 238 ppm U were 38.2 and 26.5% for imine and amide COFs, respectively.…”

“…The reduction of soluble uranyl ions to U­(IV) precipitation followed by solid–liquid separation is an effective strategy for U removal from aqueous solutions. , A series of reduction methods, such as chemical reagent reduction, reductive solid materials, electrochemical reduction, , microbial-assisted reduction, and photocatalytic reduction have been explored. Heterogeneous photocatalytic reduction is considered to be an environmentally friendly and economic method among them, especially the visible light-driven photocatalytic reduction. − However, several shortcomings of traditional photocatalysts limit their further applications, for example, the narrow band gap of TiO 2 and g-C 3 N 4 resulted in the weak utilization of visible light, high power Hg or Xe lamps are required in photocatalysis; otherwise, it usually leads to slow catalytic reduction rate U­(VI). − Efficient photocatalytic reduction of uranyl by COF materials has also been reported. COF DHBD-TMT (DHBD, 2,5-dihydroxy-1,4-benzenedicarboxaldehyde; TMT, 2,4,6-trimethyl-1,3,5-triazine) possess hydroquinone and highly planar conjugated triazine units on the skeleton, which enhances the π-electron delocalization and decreases the optical band gap, thereby COF DHBD-TMT has good light utilization ability and could reach adsorption and reduction equilibrium of 500 ppm U within 200 min, but a high power 300 W xenon lamp is needed …”

Design and Fabrication of Hypercrosslinked Covalent Organic Adsorbents for Selective Uranium Extraction

“…synthesized a novel conjugated TT-TTP COP with photocatalytic properties as uranium adsorbent. The adsorbent maintains a removal rate of U­(VI) at 89.9% even under the condition of high ionic strength (3 mol L –1 NaNO 3 ), indicating the excellent potential for practical uranium wastewater treatment . However, much attention has been paid to the design and fabrication of MOFs/COFs during the past few decades.…”

“…The adsorbent maintains a removal rate of U(VI) at 89.9% even under the condition of high ionic strength (3 mol L −1 NaNO 3 ), indicating the excellent potential for practical uranium wastewater treatment. 31 However, much attention has been paid to the design and fabrication of MOFs/COFs during the past few decades. COPs for uranium extraction and detection are not designed rationally and well explored, resulting in large limitations in their applications.…”

Efficient faradaic supercapacitor energy storage using redox-active pyrene- and benzodithiophene-4,8-dione-tethered conjugated microporous polymers

“…[35][36][37][38][39][40][41] Even though CMPs have been employed in numerous elds, including photocatalysis, drug delivery, gas storage, gas separation, dye removal, and uorescence detection, their uses as SCs electrodes are restricted by their subpar conductivity, which signicantly decreases their capacitance. [42][43][44][45][46][47][48][49][50][51][52][53][54] CMPs are generally mixed with other conductive materials to boost the conductivity of CMP-based electrodes. Unfortunately, it is challenging to considerably improve the CMP performance due to the poor connection between the CMP and conductor.…”