Porous 3D flower-like bismuth silicate@nitrogen-doped graphene nanomaterial as high-efficient catalyst for fuel cell cathode

Three-dimensional (3D) flower-like Bi₂SiO₅ nanomaterials (FLB) and 3D flower-like Bi₂SiO₅@nitrogen doped graphene nanomaterials (FLBNG) have been originally synthesized. Notably, as-synthesized FLB and FLBNG nanomaterials have not yet been discussed in previous reports. The FLBNG nanomaterials have been for the first time studied as the cathodic catalysts for Fuel cell. Research results have shown that the FLBNG-2 possesses perfectly 3D flower-like Bi₂SiO₅ with numerous uniformly coiled nanowires and exhibits good methanol immunity, high activity and high durability during oxygen reduction reaction (ORR) process under acidic and basic electrolytes. The value of onset potential (E₀) for FLBNG-2 in alkaline electrolyte can reach to 1.091 V, Tafel slope of FLBNG-2 is 45.637 mV dec⁻¹ and its limiting current density (J_L) is 6.49 mA cm⁻². Similarly, These ORR performances in acidic electrolyte are also better than those of 20 wt% commercial Pt/C and most of the associated reports. Thus, the FLBNG-2 could be a potential ORR catalyst, applied in the cathode of fuel cells to enhance the kinetic rate, decrease costs and enhance durability. And this synthesis method may be provide a good design to synthesize other 3D flower-like nanomaterials with desirable properties.