By a facile coordination-based post-synthetic strategy, the high surface area MIL-101(Cr) nanoparticles was functionallized by grafting amine group of ethylenediamine (ED) on coordinatively unsaturated Cr(III) centers, yielding a series of ED-MIL-101(Cr)-based adsorbents and their application for adsorption of U(VI) from aqueous solution were also studied. The obtained ED-functionallized samples with different ED contents were characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), FTIR, elemental analysis (EA) and N2 adsorption and desorption isothermal. Compared with the pristine MIL-101(Cr) sorbents, the ED-functionallized MIL-101(Cr) exhibits significantly higher adsorption capacity for U(VI) ions from water with maximum adsorption capacities as high as 200 mg/g (corresponding to 100% extraction rate) at pH of 4.5 with ED/Cr ratio of 0.68 and the sorbed U(VI) ions can easily be desorbed at lower pH (pH ≤ 2.0). The adsorption mode of U(VI) ions and effects of grafted ED on the MIL-101(Cr) frameworks were also been studied by X-ray absorption spectroscopy (XAS). We believe that this work establishes a simple and energy efficient route to a novel type of functional materials for U(VI) ions extraction from solution via the post-synthetic modification (PSM) strategy.
A series of Bi2S3@ZIF-8 core–shell heterostructures has been synthesized using in situ self-assembly, which exhibit enhanced photocatalytic degradation of Rhodamine B under visible-light irradiation, reaching 25.3 times that observed for pristine Bi2S3 and 26.7 times that found for commercial Degussa P25.
Ce3+, Eu2+ and Eu3+ singly activated and Ce3+/Eu2+/Eu3+-coactivated Ca11(SiO4)4(BO3)2 (CSB) phosphors were synthesized by novel and efficient aluminium reduction solid state reactions. Under ultraviolet light excitation, the Ce3+, Eu2+ and Eu3+ singly activated CSB phosphors exhibit intense red, green and blue emissions, respectively. The unique host CSB shows its superior advantages in color balance compared with the widely-used Ca2SiO4, Ca3B2O6 and Y3Al5O12. The red, green and blue colors can be controlled by the reduction temperature, and a white light emitting phosphor was obtained by reducing the as-prepared CSB:0.02Ce,0.005Eu powder at 700 °C for 8 h. The unique property of CSB in color balance was proposed to attribute to the group synergy effect. Furthermore, the energy transfer probability was discussed in detail, and the critical distance was calculated.
Recently, CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (QDs) have exhibited significant potential for application in the field of lighting. However, their self-absorption and agglomeration significantly decrease their photoluminescence when their solution is centrifuged to form a powder; this hinders their applications in the field of solid-state lighting. Currently, there is lack of efficient solutions to overcome the self-absorption issue for CsPbX3 QDs. Thus, herein, an effective strategy is proposed via the in situ growth of CsPbBr3 (CPB) QDs in a mesoporous silica (m-SiO2) matrix, where self-absorption originating from the agglomeration of the QD powder is distinctly suppressed in the m-SiO2 matrix. Furthermore, due to its higher transmissivity, some photons can transport along the channels of m-SiO2 with less light loss. As a result, the photoluminescence quantum yield (PLQY) of 68% for the CsPbBr3/m-SiO2 (CPB/MS) powder is distinctly higher than that of the discrete CPB powder (36%). In addition, the chemical stability, thermal quenching and luminous decay were evidently improved for the CPB/MS nanocomposite. Finally, a remote flexible light-emitting diode with ultrahigh stability and arbitrary bending angle was achieved, which presented a pathway for the application of CPB QDs in solid-state lighting.