A Convenient Electrochemical Method for Preparing Carbon Nanotubes Filled with Amorphous Boron

Carbon nanotubes (CNTs) with a filler possess better physicochemical properties and exhibit promising applications. A convenient method to prepare CNTs filled with boron is proposed by the electrochemical conversion of CO2 in CaCl2-CaCO3-B2O3 molten salt. Amorphous B-filling CNTs with the diameter of 10–20 nm was obtained on the nickel cathode at a potential of −1.2 V (vs. Ag/AgCl). The electroreduction process of C and B is analyzed. The formation mechanism of B-filling CNTs is discussed. Compared with other methods, the proposed approach is more convenient and environment-friendly.