Electro‑catalytic hydrogen evolution and magnetic behavior of N‑doped‑rGO supported Ni_xP_y

摘要

Search for cost effective, earth abundant electrocatalysts for hydrogen generation through water splitting is the challengeof the hour whereas multifunctional applicability of the materials is the extremely sought issue for multi-tasking smartmaterials. In this work, nitrogen doped reduced graphene oxide (N-rGO) supported nickel phosphide (Ni_xP_y) nanomaterialhas been prepared and characterized. Details electrocatalytic measurements exhibit the commendable performance ofthe composite materials against hydrogen evolution reaction in acid medium. The reduction of the required overpotentialfor reaching 10 mA/cm~2 from 265 mV (Ni_xP_y) to 248 mV (Ni_xP_y/N-rGO) is observed in 0.5 M H_2SO_4solution which proves the benefit for attaching N-rGO with Ni_xP_y.The electrochemical active surface area measurement also ascertains thequality of the composite and the enhancement of an active surface area is attributed to the attachment of N-rGO matrix.Furthermore, the Ni_xP_y/N-rGO composite confirms it’s stability in the acidic medium for 1200 min at 248 mV withoutany significant loss of current. Ground state ferromagnetic behavior has been demonstrated by Ni_xP_y/N-rGO in sharpcontrast to the paramagnetic behavior exhibited by the bare Ni_xP_ynanoclusters at low temperature. Thus, the N-rGOmatrix supported Ni_xP_ymanifests both electrocatalytic proficiency and magnetic ordering with potential application inthe future green energy as well as in data storage technologies.