Introduction

Braun, Artur; Diale, M.; Malherbe, J.B.; Braun, M. W. H.

doi:10.1557/jmr.2017.426

Cited by 2 publications

(1 citation statement)

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“…Efforts of matching of incommensurate layers in heterostructures are usually countered by formation of defects, [ 25 ] as illustrated in Figure a. Such defects can detrimentally affect the charge separation and transfer within heterostructures often as unwelcome recombination centers for the photogenerated carriers.…”

Section: Resultsmentioning

confidence: 99%

Covalent SO Bonding Enables Enhanced Photoelectrochemical Performance of Cu₂S/Fe₂O₃ Heterojunction for Water Splitting

Zhang

Huang

Zhu

et al. 2021

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O 3 ), possessing a bandgap of 1.9-2.2 eV and theoretically enabling a photocurrent density of 12.6 mA cm −2 at 1.23 V versus reversible hydrogen electrode (RHE) for water splitting, [6] become one of the most investigated photoanode materials. Additionally, Hematite has stable properties, abundant reserves, and nontoxicity compared with other photoanode materials. [7] However, the photoelectrochemical performance of hematite is severely restricted by its short hole diffusion length (≈2-4 nm), low conductivity, and short lifetime of the excited state carriers (≈10 −12 s). Furthermore, a high concentration of surface states and slow kinetics for sluggish oxygen evolution reaction (OER) at the surface of Fe 2 O 3 call for the necessary modifications to improve the PEC performance.Cu 2 S, a p-type semiconductor with a narrow bandgap (1.2 eV), is attracting broad interest for solar energy conversion and storage in numerous applications. [8][9][10] It is ideally suitable for harvesting sunlight in a wide wavelength range and simultaneously the high conductivity allows for efficient photogenerated charge transfer. Moreover, copper vacancies are generated once copper(I) sulfide is exposed to oxygen, and then an localized surface plasmon resonance band will emerge. [11,12] This property of copper sulfide enables the utilization of sunlight with the wavelength up to the near-infrared region. Due to the photothermal effect, CuS compound nanocrystals have been used widely for energy storage and photothermal therapy. [13,14] Importantly, a recent report demonstrates that the derivatives of Cu 2 S under the condition of OER The severe charge recombination and the sluggish kinetic for oxygen evolution reaction have largely limited the application of hematite (α-Fe 2 O 3 ) for water splitting. Herein, the construction of Cu 2 S/Fe 2 O 3 heterojunction and discover that the formation of covalent SO bonds between Cu 2 S and Fe 2 O 3 can significantly improve the photoelectrochemical performance and stability for water splitting is reported. Compared with bare Fe 2 O 3 , the heterostructure of Cu 2 S/Fe 2 O 3 endows the resulting electrode with enhanced charge separation and transfer, extended range for light absorption, and reduced charge recombination rate. Additionally, due to the photothermal properties of Cu 2 S, the heterostructure exhibits locally a higher temperature under illumination, profitable for increasing the rate of oxygen evolution reaction. Consequently, the photocurrent density of the heterostructure is enhanced by 177% to be 1.19 mA cm −2 at 1.23 V versus reversible hydrogen electrode. This work may provide guideline for future in the design and fabrication of highly efficient photoelectrodes for various reactions.

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Section: Resultsmentioning

confidence: 99%