文摘
Mass production of high-quality graphene sheets is essential for their practical application in electronics, optoelectronics, composite materials, and energy-storage devices. Here we report a prompt electrochemical exfoliation of graphene sheets into aqueous solutions of different inorganic salts ((NH4)2SO4, Na2SO4, K2SO4, etc.). Exfoliation in these electrolytes leads to graphene with a high yield (>85%, 鈮? layers), large lateral size (up to 44 渭m), low oxidation degree (a C/O ratio of 17.2), and a remarkable hole mobility of 310 cm2 V鈥? s鈥?. Further, highly conductive graphene films (11 惟 sq鈥?) are readily fabricated on an A4-size paper by applying brush painting of a concentrated graphene ink (10 mg mL鈥?, in N,N鈥?/i>-dimethylformamide). All-solid-state flexible supercapacitors manufactured on the basis of such graphene films deliver a high area capacitance of 11.3 mF cm鈥? and an excellent rate capability of 5000 mV s鈥?. The described electrochemical exfoliation shows great promise for the industrial-scale synthesis of high-quality graphene for numerous advanced applications.