Multi-template synthesis of hierarchically porous carbon spheres with potential application in supercapacitors

A new and simple multi-template approach towards hierarchical porous carbon (HPC) materials was reported. HPC spheres were prepared by using hierarchical silica capsules (HSCs) as the hard template and triblock copolymer Pluronic P123 as the soft template. Three types of pores were tunably constructed in the HPC spheres in a wide size range of 3.0 to 100 nm. Since the HSCs were in situ constructed by silica nanoparticles, which were formed from the sol–gel system of tetraethylorthosilicate and (3-aminopropyl)triethoxysilane (APTES), the porous structures of HPCs were simply controlled by changing the size of silica nanoparticles, i.e. by varying the APTES content. Thanks to their high surface areas and interconnected pores, the HPCs exhibited good electrochemical performance with specific capacitances of up to 170 F g−1 and outstanding cycling stability without capacitance loss after 5000 cycles.