论文部分内容阅读
In this work,hybrid material CNTs@MIL-101(Cr) was synthesized in 2 h using multi-walled carbon nanotubes(MWCNTs) as the crystal growth accelerator with hydrothermal method.The characteristic differences between the crystals of CNTs@MIL-101(Cr) and MIL-101 were investigated by N_2 adsorption–desorption isotherms,X-ray diffraction(XRD),scanning electron microscope(SEM) and thermogravimetric analyzer(TGA).The results showed that MWCNTs embedding in the hybrid material provide more mesoporous volumes than that of MIL-101.Moreover,the fast synthesized crystals of CNTs@MIL-101(Cr) still preserve the octahedral shape like MIL-101 and have a larger size ranging from 1.5 to 2.0 μm which were approximately three times larger than that of MIL-101.In the proposed mechanism,the roles of MWCNTs played in the crystallization were discussed where MWCNTs can be seen as coaxial cylindrical tubes composed of multi-layer graphenes and the place where nucleation and crystal growth processes occur at the tubes’ out surface.Then,a crystal seeding layer bonding with the MWCNTs may be easily formed which accelerates the growth rate of MIL-101 crystals.Thus,larger crystals of CNTs@MIL-101(Cr) were formed due to the faster crystal growth rate of MIL-101.
In this work, hybrid material CNTs @ MIL-101 (Cr) was synthesized in 2 h using multi-walled carbon nanotubes (MWCNTs) as the crystal growth accelerator with hydrothermal method. The characteristic differences between the crystals of CNTs @ MIL-101 Cr and MIL-101 were investigated by N2 adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analyzer (TGA). The results showed that MWCNTs embedding in the hybrid material provide more mesoporous volumes than that of MIL-101. Moreover, the fast formed crystals of CNTs @ MIL-101 (Cr) still preserve the octahedral shape like MIL-101 and have a larger size ranging from 1.5 to 2.0 μm which were approximately three times larger than that of MIL-101.In the proposed mechanism, the roles of MWCNTs played in the crystallization were discussed where MWCNTs can be seen as coaxial cylindrical tubes composed of multi-layer graphenes and the place where nucleation and crystal growth processes occur at the tubes’ out surface. Chen, a crystal seeding layer bonding with the MWCNTs may be easily formed of accelerating the growth rate of MIL-101 crystals. Thus, larger crystals of CNTs @ MIL-101 (Cr) were formed due to the faster crystal growth rate of MIL-101.