Synthesis and characterization of carbon sphere-supported sand-rose like N-GQDs/NiCo2S4 structures with synergetic effect for development of hydrogen storage capacity

Abstract

Porous carbon spheres (CSs) decorated with sand-rose shaped NiCo2S4/Co9S8/CoS and N- doped graphene quantum dots (N-GQDs) were prepared via one-step free-surfactant hydrothermal route. Ni-Co sulfide based materials (NCS) were created in the presence of Tioglycolic acid (TGA) as both sulfur source and capping agent. Altering of synthesis parameters involving metal salt type, TGA and NaOH amount help to control the sulfide-based materials features. The obtained 3D hierarchical N-GQD/NCS/CS core-double shell spheres were considered in terms of morphology, dimension and porosity. Different formed Ni-Co sulfide structures were evaluated for hydrogen storage capacity. The achieved 3D microspheres could be utilized as a favorable candidate in electrochemical hydrogen storage, incorporating the prominent electro-conductivity of N-GQDs and CSs carbonic materials and high capacity of sand-rose shaped NCS nanostructures. Carbon microspheres formed through rapid sonochemical approach and various linear amines were applied as conductive support. It was discovered that the presenting of N-GQDs prominently improves the discharge efficiency of the core-double shell spheres from 930 to 1244 mAh g−1 because of trap positions formed by both Nitrogen dopants and edge conditions which can adsorb charge transporters to rise the storage proficiency.