Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Jul 5;15(32):12973-12982.
doi: 10.1039/d4sc03442b. eCollection 2024 Aug 14.

Enhanced photoelectrochemical water splitting performance of α-Fe2O3 photoanodes through Co-modification with Co single atoms and g-C3N4

Affiliations

Enhanced photoelectrochemical water splitting performance of α-Fe2O3 photoanodes through Co-modification with Co single atoms and g-C3N4

Juan Wu et al. Chem Sci. .

Abstract

The practical application of α-Fe2O3 in water splitting is hindered by significant charge recombination and slow water oxidation. To address this issue, a CoSAs-g-C3N4/Fe2O3 (CoSAs: cobalt single atoms) photoanode was fabricated in this study through the co-modification of CoSAs and g-C3N4 to enhance photoelectrochemical (PEC) water splitting. The coupling between g-C3N4 and α-Fe2O3 resulted in the formation of a heterojunction, which provided a strong built-in electric field and an additional driving force to mitigate charge recombination. Moreover, g-C3N4 served as a suitable carrier for single atoms, which effectively anchored CoSAs through N/C coordination. The highly dispersed CoSAs provided abundant active sites, which further promoted surface holes extraction and oxidation kinetics, resulting in higher PEC performance and photostability. This study indicates the benefits of these collaborative strategies and provides more efficient designs for solar energy conversion in PEC systems.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1
Fig. 1. (a) Schematic of the CoSAs–g-C3N4/Fe2O3 NRA photoanode preparation process. Top-view SEM images of (b) α-Fe2O3; (c) g-C3N4/Fe2O3; (d) CoSAs–g-C3N4/Fe2O3.
Fig. 2
Fig. 2. (a)–(c) Atomic-resolution TEM images of CoSAs–g-C3N4/Fe2O3 NR (CoSAs are highlighted by red circles); (d) and (e) HRTEM image and EDS mapping of Co, Fe, O, C, and N for CoSAs–g-C3N4/Fe2O3 NR.
Fig. 3
Fig. 3. High-resolution XPS spectra of (a) C 1s; (b) N 1s; (c) O 1s; (d) Co 2p, for CoSAs–g-C3N4/Fe2O3.
Fig. 4
Fig. 4. (a) XANES spectra; (b) R-space Co K-edge EXAFS spectra; (c) EXAFS R-space fitting curve; (d) WT-EXAFS signals of Co foil, CoO, CoPc and CoSAs–g-C3N4/Fe2O3.
Fig. 5
Fig. 5. (a) LSV curves; (b) transient photocurrent measurements at 1.23 VRHE; (c) IPCE curves; (d) ABPE curves of α-Fe2O3, g-C3N4/Fe2O3, and CoSAs–g-C3N4/Fe2O3 photoanodes.
Fig. 6
Fig. 6. (a) M–S plots; (b) OCP transient decay curves; (c) potential (VRHE) versus time for the photoelectrodes at 1 mA cm−2; (d) ηbulk; (e) ηsurface; (f) EIS of α-Fe2O3, g-C3N4/Fe2O3, CoSAs–g-C3N4/Fe2O3 photoanodes.
Fig. 7
Fig. 7. (a) Photocurrent density stability of CoSAs–g-C3N4/Fe2O3 photoanodes at 1.23 VRHE; (b) XRD pattern; (c) SEM; (d) HRTEM of CoSAs–g-C3N4/Fe2O3 photoanodes after long-term stability tests.
Fig. 8
Fig. 8. (a) Calculated band gap values (based on UV-Vis absorption spectra) of α-Fe2O3 and g-C3N4. Ultra UV photoelectron spectroscopy (UPS) and work function of (b) α-Fe2O3 and (c) g-C3N4; (d) energy band diagram of the g-C3N4/Fe2O3 heterojunction; (e) Schematic illustration of electron–hole separation of CoSAs–g-C3N4/Fe2O3 photoanode for PEC water splitting.

References

    1. Peng Z. Su Y. Ennaji I. Khojastehnezhad A. Siaj M. Chem. Eng. J. 2023;477:147082. doi: 10.1016/j.cej.2023.147082. - DOI
    1. Bai W. Li H. Peng G. Wang J. Li A. Corvini P. F.-X. Appl. Catal., B. 2024;352:124023. doi: 10.1016/j.apcatb.2024.124023. - DOI
    1. Gao R. T. Liu L. Li Y. Yang Y. He J. Liu X. Zhang X. Wang L. Wu L. Proc. Natl. Acad. Sci. U. S. A. 2023;120:e2300493120. doi: 10.1073/pnas.2300493120. - DOI - PMC - PubMed
    1. Gao R. T. Nguyen T. N. Nakajima T. He J. Liu X. Zhang X. Wang L. Wu L. Sci. Adv. 2023;9:eade4589. doi: 10.1126/sciadv.ade4589. - DOI - PMC - PubMed
    1. Wang L. Zhu J. Liu X. ACS Appl. Mater. Interfaces. 2019;11:22272–22277. doi: 10.1021/acsami.9b03789. - DOI - PubMed

LinkOut - more resources