Graphene-PEDOT-Platinum Tertiary Composite Material Based Catalyst for Hydrogen Evolution Reaction

Abstract

We fabricated a Laser Scribed Graphene-PEDOT-Platinum (LSG-PEDOT-Pt) tertiary composite material, using a three-step synthesis process, to investigate its catalytic hydrogen evolution reaction (HER) performance: 1. Graphene oxide film was photo-thermally reduced via a CO­­2 laser into laser-scribed graphene (LSG). 2. A layer of PEDOT polymer was grown on top of the LSG film using vapor assisted polymerization methods to yield a LSG-PEDOT composite film. 3. Platinum nanoparticles were deposited on the LSG-PEDOT composite via pulse-potentiometry. The vapor-assisted polymerized PEDOT decorates the surface of the LSG, forming nanoribbon/wire like structures. The pulse potentiommetry enables platinum to grow vertically on top of the LSG-PEDOT substrate, forming arrays of nanowires. The composite material shows better HER performances than metal platinum in 0.5M H2SO4 solution, with a very low Tafel slope of 29mV/decade, 15mV (vs. RHE) onset overpotential, and achieves 10mA/cm2 current density at a low overpotential of 35mV (vs. RHE). Even though LSG-PEDOT is an intrinsically poor HER catalyst, its high surface area, high conductivity and low charge transfer resistance make LSG-PEDOT a good substrate for HER catalysis material, as demonstrated by the performances of LSG-PEDOT-Pt. LSG-PEDOT composite material could be a promising base material for developing non-noble metal based catalysts. Figure 1