Solar light assisted green synthesis of palladium nanoparticle decorated nitrogen doped graphene for hydrogen storage application

Abstract

Recent research developments reveal that nanomaterials, especially carbon nanomaterials, can play a significant role in the performance enhancement of energy conversion and storage devices. The synthesis procedure of nanomaterials, however, remains one of the governing factors for their wide scale implementation. In this paper, an in situ synthesis method to prepare palladium nanoparticle decorated nitrogen doped graphene sheets (Pd/N-SG) using focused solar radiation is developed. The present synthesis technique combines three processes simultaneously, namely (a) graphene sheet formation, (b) nitrogen doping of graphene sheets and (c) metal precursor reduction to metal nanoparticles, in one step through a green approach. The hydrogen storage properties of the Pd/N-SG sample are investigated using high pressure Sievert’s apparatus and the sample exhibits an excellent hydrogen storage capacity of 4.3 wt% at room temperature (25 °C and 4 MPa hydrogen pressure). The method developed for the synthesis is environmentally benign, easy to adopt and economical. Also, the proposed one-step synthesis method can be easily scaled up to large quantities and this opens a new pathway for the synthesis of nanomaterials for use in the renewable energy field.