One-step hydrothermal synthesis of honeycomb 3D graphene-like Co9S8 and its catalytic characteristics for NaHCO3 reduction by H2S

Abstract Honeycomb 3D graphene-like Co 9 S 8 nanocrystallines were successfully synthesized using cobalt and Na 2 S·9H 2 O as starting materials without a template via a simple hydrothermal route. The composition, structure, morphology, and catalytic activity of the as-prepared Co 9 S 8 were characterized by investigation of XRD, SEM, EDS, XPS, GC–MS and HPLC. It was found that an appropriate concentration of inexpensive NaHCO 3 play a critical role for the formation of honeycomb Co 9 S 8 nanocrystallines. On the other hand, Co 9 S 8 acted as a catalyst in the hydrothermal reaction, producing formic acid reduced from NaHCO 3 as high as 3680 mg/L. It indicates that the present study not only proposes a simple way of honeycomb Co 9 S 8 synthesis, but also provides a potential approach to CO 2 reduction.