▎ 摘　　要

Direct, metal-free synthesis of graphene films on insulating substrates in a controlled manner is of great importance for applications in (opto)electronic and energy storage devices. Graphene films are fabricated on fused silica substrates without metal catalyst via chemical vapor deposition (CVD), using propionic acid as a carbon source. Film-thickness is readily adjustable between 5 and 45 nm by changing the deposition time and flow rate of the precursor, displaying sheet resistance in the range of 0.27-1.86 k omega(-1). The resulting graphene films are directly integrated into micro-supercapacitors without film transfer or liquid-phase processing, and demonstrate ultrahigh operation rates up to 1000 V s(-1). Moreover, these films exhibit excellent rate capabilities, achieving a high volumetric capacitance of 131 F cm(-3) at 10 mV s(-1).