MXenes and MXene-based composite materials have potential applications in a wide range of areas due to their unique physical and chemical characteristics. At present, it is still a major challenge to develop a simple, safe, and efficient route to prepare MXenes without using fluorinated etchants. Herein, we design a facile method to prepare Ti3C2Tx MXene sheets by selectively etching Ti3AlC2 powders in an aqueous diluted H2SO4 solution with H2O2 as an oxidant. In a system of H2SO4 and H2O2, an aqueous H2SO4 solution with a concentration of 6mol...