Poly(3-Hexylthiophene) Stabilized Ultrafine Nickel Oxide Nanoparticles as Superior Electrocatalyst for Oxygen Evolution Reaction: Catalyst Design Through Synergistic Combination of Pi-Conjugated Polymers and Metal-Based Nanoparticles

Abstract

We report the synthesis and electrocatalytic activity of poly(3-hexylthiophene) stabilized nickel oxide nanoparticles (P3HT@NiO NPs). Employing semiconducting P3HT as a stabilizing agent produced well dispersed P3HT@NiO NPs with uniform size distribution (2.5 +/- 1.2 nm). For comparison, NiO NPs stabilized with the small molecule 3-hexylthiophene (3HT@NiO NPs) were also synthesized and characterized as reference material. The physiochemical properties of the developed hybrid P3HT@NiO were fully characterized using UV/Vis absorption spectroscopy, fluorescence spectroscopy, high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The electrocatalytic activities of the developed semiconducting polymer-stabilized NPs were evaluated for the oxygen evolution reaction (OER) of water splitting. Our work reveals the electronic communication between P3HT and NiO NPs and demonstrates that P3HT@NiO NPs exhibit superior catalytic activity with an overpotential of 310 mV when compared to the reference 3HT@NiO NPs which exhibited an overpotential 560 mV. These results suggest that the heteroatom-containing pi-conjugated semiconducting polymers can be employed as electrocatalytic performance enhancing and stabilizing ligands for the synthesis of ultrafine metal-based NPs as efficient electrocatalytic platforms.