Cellulose‐Based Reduced Nanographene Oxide on Gold Nanoparticle Supports for CO2 Electrocatalysis

Abstract

AbstractCellulose‐based reduced graphene oxide materials (r‐nGO) were fabricated and anchored onto polyvinyl alcohol stabilized gold nanoparticles. Their potential in applications in the electrocatalytic reduction of CO2 (ER‐CO2) is demonstrated. The nGO was synthesized by microwave‐assisted cellulose carbonization followed by two different reduction methods, that is, with super‐heated water (i) or caffeic acid (ii). These materials, denoted as r‐nGO (i) r‐nGO‐CA (ii), were utilized to immobilize colloidal gold nanoparticles (Au NPs) in an aqueous environment. The two r‐nGO‐supported Au NP materials were deposited on glassy carbon electrode surfaces and studied as catalysts for ER‐CO2. ER‐CO2 was investigated at room temperature and pressure (RTP) using ionic liquids (RTILs) or an aprotic solvent acetonitrile (ACN). Tetrabutylammonium hexafluoroborate (TBAPF6) was used as an electrolyte salt in the case of ACN. The current response resulting from ER‐CO2 was measured under cyclic voltammetric conditions using a one‐compartment three‐electrode cell. Results showed that, r‐nGO‐supported gold nanoparticles catalyze ER‐CO2 and they significantly reduce the overpotential of CO2 reduction from −1.9 V to −1.6 V vs. Ag/AgCl. Moreover, of all the materials studied, Au/r‐nGO was superior in reducing CO2 in both RTILs and TBAPF6/ACN. These outcomes serve as grounds for the further development of electrocatalysts from bio‐based reduced graphene oxides.