Ni-Pt coating on graphene based 3D printed electrodes for hydrogen evolution reactions in alkaline media

[Display omitted] •Graphene based 3D printed electrodes are prepared for HER.•Ni and Pt were successfully electrodeposited on 3D printed electrodes.•The presence of Pt in the electrode is improved the kinetic activity of NiPt electrodes.•NiPt3 electrode sample has two and half lower overpotential than uncoated sample. Additive manufacturing (AM), a three-dimensional (3D) printing method has attracted great attention in manufacturing technology because of the low cost of fabrication of medium to small sizes of products, fast prototyping, and high precision. The 3D printing method has emerged as an innovative interface in electrode applications due to the opportunity to use conductive Polylactic Acid (PLA) filaments. In this study, Nickel (Ni) and Platinum (Pt) with different metal ratios were deposited on 3D printed electrodes and prepared using conductive graphene-based PLA filament. Then, the NiPt coated 3D printed graphene-based electrodes were modified by different metal ratios of Ni/Pt: 1:1, 1:2, and 1:3, called NiPt1, NiPt2, and NiPt3, respectively. The physical properties of the NiPt coated 3D printed electrodes were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), FE-SEM/Energy Dispersive X-ray Spectroscopy (FE-SEM/EDX), FE-SEM mapping, X-ray Powder Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS) techniques. Electrochemical measurements of the electrodes were examined by using Linear Sweep Voltammetry (LSV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS), Tafel polarization analysis and Chronoamperometry (CA) techniques. The results showed that on NiPt3 3D printed electrode surface, the current density was improved by 25% compared to the other electrode samples. Moreover, it was found that the NiPt3 coated 3D printed electrode had 1.5 times higher current density than the NiPt1 coated 3D printed electrode for HER.