High hydrogen storage capacity of heteroatom-containing porous carbon nanospheres produced from cross-linked polyphosphazene nanospheres

Abstract

Heteroatom-containing porous carbon nanospheres were fabricated by forming polyphosphazene nanospheres and carbonizing them with NaOH as activating agent. They were then examined as a material for hydrogen storage. N2 sorption and H2 sorption measurements showed that the carbon nanospheres possess a BET surface area of 1140m2g−1, a total pore volume of 0.90m3g−1, an ultramicropore volume of 0.30m3g−1, a bimodal pore size distribution (3–5nm and 0.6–0.8nm diameter pores), and a gravimetric hydrogen uptake of 2.7 wt.% at 77k and 1atm.