General synthesis of MXene by green etching chemistry of fluoride-free Lewis acidic melts

The MXene has emerged as a rising star on the horizon of material science due to widespread applications ranging from energy and catalysis to biomedicine[1,2].These two-dimensional(2D)transition metal carbides/nitrides well collect a variety of attractive properties such as rich surface chemistry,high hydrophily,and metallic conductivity that are difficultly attained for all in conventional 2D atomic crystals[3,4].