Introducing Platinum Nanoparticles on Inorganic/Organic Nanoheterostructures for Enhancing their Efficiency toward the Photoelectrochemical Urea Oxidation Reaction

Abstract

TiO2-based inorganic/organic nanoheterostructure (NHs) photoanodes have been widely employed for visible-light-driven photoelectrochemical (PEC) urea oxidation to produce hydrogen (H2). The efficiency of these NHs toward the PEC urea oxidation reaction (UOR) is further enhanced by anchoring platinum (Pt) nanoparticles (NPs) on inorganic/organic NHs. In this article, Pt nanoparticle-decorated inorganic/organic NHs (Pt@TiO2/NDIPh) were fabricated for the PEC UOR. These NHs consist of a N,N-bis(hexyl)-2,6-(phenyl)-naphthalenediimide (NDIPh) thin layer on TiO2 nanorods (TiO2/NDIPh). To these TiO2/NDIPh NHs, the Pt NPs are anchored by the magnetron sputtering technique. The Pt NPs on TiO2/NDIPh NHs act as a protective layer, increasing the stability of the NHs. The significance of introducing Pt NPs to inorganic/organic NHs is explored through PEC studies under light illumination conditions. Pt@TiO2/NDIPh NHs achieve a high current density and provide long-term stability over light illumination with 92% faradaic efficiency. The improved PEC performance of the Pt-decorated NHs was attributed to an increased separation of the photogenerated electron–hole charge carriers.