Synergistic Effect Of Nano-sized Carbon Blacks On The Preparation Of Carbon Nanotubes And Carbon Black-soldering Carbon Nanotube Networks From Polyolefins

Using low-cost plastics as carbon source presents a sustainable and environmental benign route for the preparation of carbon nanomaterials.However,the current catalysts basically take effect on a certain type of plastic.Herein,a kind of universal catalyst,Ni-Mo-Mg catalyst combined with CB,has been found to effectively catalyze polyolefin to form carbon nanotubes and carbon black-soldering carbon nanotube networks in this work.A significantly universal carbonization performance of Ni-Mo-Mg catalyst has been created for polypropylene(PP),polyethylene(PE),polystyrene(PS)and their blends with the highest CNTs yields of 26.24%,28.36%,18.39% and 31.66%.With the further introduction of a universal synergistic agent(carbon black),the maximum CNTs yields of 53.56%,65.95%,41.85% and 59.83% from PP,PE,PS and their blends were achieved,respectively.The morphology,microstructure and the graphitization of above CNTs were measured by scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution transmission electron microscope(HRTEM),X-ray diffractometer(XRD)and Raman spectroscopy.Results demonstrated that the addition of carbon black could further improve the morphology of CNTs and enhance the graphitization of CNTs.Finally,the highly universal carbonization performance of Ni-Mo-Mg catalysts and the universal synergistic effect were also discussed.A kind of junction-soldered CNT networks has been successfully prepared just by adding a kind of carbon black into the catalytic carbonization of PP.Scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were applied to measure the morphology and microstructures of CNT networks.X-ray diffractometer(XRD),Raman spectroscopy,thermogravimetric analysis(TGA)and X-ray photoelectron spectroscopy(XPS)were used to characterize the phase structures,thermal stability and surface compositions of the CNT networks.Results demonstrated that the added CB-1 not only had a positive effect on the CNTs yield from PP/Ni-Mo-Mg,but also soldered the forming CNTs to form a novel CB-soldering CNT network.By analyzing the formation mechanism,the increased effect on CNTs yield should come from its radical trapping ability,while the soldering performance was heavily dependent on the size of CB.