Enhancing the Photoelectrochemical Performance of a Hematite Dendrite/Graphitic Carbon Nitride Nanocomposite through Surface Modification with CoFeOx

Abstract

AbstractIn this article, we report the surface modification of a hematite dendrite/graphitic carbon nitride composite (HD/g‐CN) with an oxygen evolution catalyst (OER), specifically CoFeOx, to achieve enhanced photoelectrochemical (PEC) water splitting under visible‐light irradiation. Such modified hematite dendrites are studied for the first time for PEC water splitting and demonstrate higher activity compared to unmodified composites. The synthesized composites are characterized by X‐ray diffraction spectroscopy, Raman spectroscopy, field emission scanning electron microscopy (FESEM) and elemental dispersive analysis (EDX). The photoelectrochemical performance was studied by linear sweep voltammetry (LSV) under visible‐light irradiation. The photoelectrochemical characterization reveals that the CoFeOx/HD/g‐CN composite shows a maximum photocurrent density of 0.60 mA cm−2 at 1.23 V versus RHE (reversible hydrogen electrode), which is comparable to the best reported value of hematite. A Mott–Schottky analysis demonstrates the formation of a p–n heterojunction of CoFeOx with the HD/g‐CN composite which is responsible for the enhanced PEC activity as a result of efficient separation of photogenerated electron–hole pairs.