Enhanced Hydrogen Evolution Reaction By Porous Curcumin Enveloped Gold Nanoparticles

Abstract

We report a facile electrosynthesis (constant current of 0.5 mA) of gold-curcumin (Au-CM) nanocomposite using a gold wire (anode) and glassy carbon electrode (cathode, GCE) in a solution of curcumin. A thin and stable film of the nanocomposite was deposited on the GCE in 30 minutes. Extensive morphological and structural characterizations were carried out by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and BET analysis, which confirmed the formation of gold nanoparticles enveloped by a porous network of curcumin. Hydrogen evolution reaction (HER) was carried out in an aqueous solution of 0.5 M sulfuric acid with the modified GCEs. Enhanced hydrogen evolution activity was observed with Au-CM/GCE by a reduction in potential from -0.43 V (Au/GCE) to -0.32 V (Au-CM/GCE) (vs. Ag/AgCl: RE) with a 2-fold increase in current density compared to bare gold. A decrease in charge transfer resistance (9.13 kΩ to 82.6 Ω) was observed with the rise in cathodic potential from (-0.3 V to -0.48 V) at Au-CM/GCE, implying the facile nature of reaction at higher potential due to faster electron flow across the electrode-electrolyte interface. This is the first report wherein the curcumin network in the Au-CM nanocomposite aids in reducing 110 mV potential during the HER compared to bare Au. Figure 1