Improving the performance of a titanium carbide MXene in supercapacitors by partial oxidation treatment

MXenes are a family of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides that are supposed to be promising materials for high pseudocapacitive energy storage. It has been proven that Ti3C2Tx (T-x refers to -F, & xe001;O, -Cl and -OH) MXenes with more O-termination could exhibit better performance in pseudocapacitors. However, direct oxidation modification would result in the serious oxidation of Ti3C2Tx into titanium dioxide. Here we report the controllable oxidation of Ti3C2Tx by readily adjusting the loading of ammonium persulfate, in order to turn the -F terminal groups to -O terminal groups on the Ti3C2Tx MXene. The partially oxidized Ti3C2Tx achieved a high capacitance of 303 F g(-1) at 2 mV s(-1), and 96.6% capacity can remain even after 9000 cycles. Hence, the controllable oxidation modification of Ti3C2Tx could be a promising strategy for surface modification of MXenes.