Enhanced Photoelectrochemical Performance in Reduced Graphene Oxide/BiFeO₃ Heterostructures

Abstract

BiFeO (BFO)-based ferroelectrics have been proved to be visible-light-driven photoelectrodes for O production. However, the hitherto reported photoelectrochemical performances remain inferior to meet the requirements for any applications. Besides, expensive noble metals (Ag, Au) are commonly required to achieve high photoelectric conversion efficiency. Here, the significant enhancements of photoelectrochemical performance is reported by fabricating a noble-metal-free reduced graphene oxide (RGO)/BFO composite film via a simple and cost-effective solution process. The optimized RGO/BFO composite film exhibits a 600% improvement of the short-circuit photocurrent density compared to that of the pristine BFO, and also outperforms the noble-metal/BFO cells under the same reaction conditions. Furthermore, the incident photon-to-current efficiency of the optimized RGO/BFO sample shows threefold enhancement. This study delivers a facile and low-cost approach to preparing 2D materials/ferroelectric heterostructures and offers a promising pathway to boost the performance of semiconducting ferroelectric photoelectrodes.

Regulation of Ferroelectric Polarization to Achieve Efficient Charge Separation and Transfer in Particulate RuO2/BiFeO3 for High Photocatalytic Water Oxidation Activity

“…[ 16 ] Enhanced photoelectric activities have been also reported for several other ferroelectric semiconductor materials. [ 17–19 ] Unfortunately, relatively low photocurrent densities were usually observed, and the reason behind is still under debate. Control of granularity and centrosymmetry were considered as promising strategies to improve photovoltaics, however, poorly controllable interfaces [ 20 ] and large bandgaps of the majority of the ferroelectric materials studied so far limit achievement of high photocurrent density.…”

“…[ 26–28 ] Due to the presence of spontaneous polarization (≈120 μC cm −2 for R‐phase and up to 150 μC cm −2 for T‐phase), [ 29 ] BFO may serve as a benchmark visible light absorbing ferroelectric photocatalyst to study the effect of ferroelectric properties on charge separation and transfer in photocatalysis. [ 30 ] It should mention here that BFO as particulate photocatalyst [ 19,28 ] or photoelectrocatalyst [ 17,18,31 ] for water splitting have been already reported, but the activities are either quite low or normal using plasmonic Au as light absorber. The intrinsic ferroelectric polarization for charge separation and transfer has not been fully exploited.…”

In‐Situ Synthesis of Tetraphenylporphyrin/Tungsten (VI) Oxide/Reduced Graphene Oxide (TPP/WO3/RGO) Nanocomposite for Visible Light Photocatalytic Degradation of Acid Blue 25

“…The photogenerated electron‐hole pairs occurred when WO 3 was exposed to visible light as discussed in the optical properties section. The photogenerated electrons were transported through RGO to the photoactive surface of the catalyst to interact with adsorbed O 2 to form • O 2 − while the photogenerated holes reacted with water and produced • OH radicals . The • O 2 − superoxide and • OH radicals synergistically act as strong oxidizing agents for the mineralisation of AB25 dye adsorbed.…”

Enhanced Visible Light Driven Photocatalytic Behavior of BiFeO3/Reduced Graphene Oxide Composites

“…A large number of RGO nanosheets attach to the surface of the BFO particles, resulting in an increased contact area between photocatalyst and organic pollutants; (3) A decrease in the recombination of the electron-hole pairs. The close contact between BFO and RGO leads to the transport of photogenerated carriers at the interface, and a semiconductor heterostructure may be formed locally [ 45 ]. It is believed that the delocalized conjugated structure and superior electrical conductivity of RGO facilitate the photogenerated electrons transferring from the conduction band of BFO to RGO, consequently suppressing the photogenerated electron-hole recombination, and eventually leading to the enhanced photocatalytic performance; (4) The affinity of graphene to dye molecules.…”