▎ 摘　　要

The development of effective strategies for the massive production of layer-number tunable graphene is of great importance to satisfy the requirements in versatile applications such as energy storage, thermal management, photocatalysis. However, how to prepare the layer-tunable graphene by a simple and efficient way is still a great challenge. Herein, an attempt has been made to exfoliate graphite into layer-tunable graphene by simply soaking the graphite in a binary-component solution composed of H2SO4 and (NH4)(2)S2O8. In this one-step method, we demonstrate that the layer-number for the as-prepared graphene can be significantly reduced by increasing the exfoliating temperature. An average thickness of similar to 20, similar to 10, and similar to 3 atomic layers can be obtained for the graphene samples exfoliated at the temperature of 30 degrees C, 60 degrees C, and 90 degrees C, respectively. Meanwhile, higher exfoliating temperature not only facilitates the higher efficiency in the exfoliation of graphite, but also achieves a superior conductivity for the prepared graphene. We have demonstrated for the first time that controlling in a sole factor of temperature can effectively tune the layer-number of graphene by a one-step chemical exfoliation method, which will find its great potential in the practical application where the designated property of graphene is required.