▎ 摘　　要

The hard template approach for preparing porous materials allows one to be able to control pore size and particle morphology. However, the cost of this method is a crucial factor for mass production. In this work, commercially available low-cost hydrophobic CaCO3 spheres (HCS) of different particle sizes were used as hard templates for preparing porous reduced graphene oxide (RGO). Nitrogen physisorption, field-emission scanning electron microscopy and transmission electron microscopy images, and the electrochemical impedance spectroscopy technique revealed that the HCS acted as a template to generate hierarchical pores in the resultant RGO. A porous RGO sample with a specific surface area of 540 m(2) g(-1) templated by HCS with an average diameter of about 50 nm exhibited a gravimetric charge-discharge capacitance of 201 F g(-1) at a current density of 0.1 A g(-1). After 1000 continuous cycles, the electrode retained about 98.4% of its initial capacitance. This HCS template method provides a viable and inexpensive route to mass production of graphene-based porous materials for electrochemical energy storage.