Flexible gold nanoparticles/rGO and thin film/rGO papers: novel electrocatalysts for hydrogen evolution reaction

BACKGROUND Fabrication of cost-effective and durable materials for efficient hydrogen production in splitting water (hydrogen evolution reaction) is of importance for the successful utilization of hydrogen-based green energy technologies. Therefore, electrocatalytic materials have been designed with a simple approach using electrodeposition of gold nanoparticles (AuNPs) and thin film (AuTF) directly on reduced graphene oxide (rGO) paper. As-prepared paper electrocatalysts (AuNPs/rGO and AuTF/rGO) were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). RESULTS Free-standing and flexible AuNPs/rGO and AuTF/rGO electrocatalysts have exhibited excellent performances on HER with low Tafel slopes (88 and 112 mV dec(-1)), low onset potentials (-47 and -55 mV), small overpotentials of only -176 and -204 mV to drive 10 mA cm(-2), respectively, and high durability even with the rolled design. The outstanding performance of these two electrocatalysts can be attributed to the uniform distribution of 20-nm-sized AuNPs and the deposition of well-ordered AuTF on rGO paper, providing an increment in the surface area and an enhancement of the electron density. CONCLUSION The controllable design of AuNPs/rGO and AuTF/rGO electrocatalysts, together with their high flexibility, good stability and promising results, suggest potential use in future applications of H-2 production in splitting water. (c) 2019 Society of Chemical Industry