Promoting photocarrier separation for photoelectrochemical water splitting in α-Fe2O3@C
- 38 Downloads
Core-shell-nanostructured hematite@graphite (α-Fe2O3@C) for photoelectrochemical (PEC) water splitting was innovatively prepared from graphite-encapsulated iron (Fe@C) nanoparticles by the arc-discharge method. The graphite was successfully controlled from dozens to few layers, and Fe was transformed into α-Fe2O3 with particle size of 20–30 nm during the thermal oxidation. α-Fe2O3@C was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. The photocurrent density of α-Fe2O3@C reached a maximum of 20 μA/cm2 at 1.23 VRHE when there were 2–3 layers of graphite and the film thickness was 200 nm. Herein, graphite was proven to play the key role in coupling between light blocking and enhanced photocarrier separation rather than changing the density of the oxygen vacancies. The addition of graphite layers enhanced the photocurrent density by 20 times compared with that of the bare α-Fe2O3 particle film derived from the hydrothermal method, which was further demonstrated by electrochemical impedance spectra (EIS).
KeywordsCore-shell α-Fe2O3@C Photoelectrochemistry Water splitting Charge separation
This work was supported by the Research Foundation of Young Teachers in Anhui University of Technology (QZ201720 and QZ201605), University Natural Science Research Project of Anhui Province (KJ2018A0055), and the Joint Funds of the National Natural Science Foundation of China (U1860201), Anhui Provincial Natural Science Foundation (1908085QE179, 1908085QE192).
Compliance with ethical standards
Conflict of interest
The authors declare they have no conflicts of interest.
- Legodi MA (2008) Raman spectroscopy applied to iron oxide pigments from waste materials and earthenware archaeological objects. Diss. University of PretoriaGoogle Scholar
- Li Y, Wang J, Li S, Wu Y, Wang J, Cao F, Qin G (2018) Solar energy protects steels against corrosion: enhanced protection capability achieved by NiFeO decorated BiVO4 photoanode. Mater Res Bull 107:416–420. https://doi.org/10.1016/j.materresbull.2018.08.015 CrossRefGoogle Scholar
- Sun S, Larry D (2008) Introduction to organic electronic and optoelectronic materials and devices, illustrated. Taylor & FrancisGoogle Scholar
- Tavakkoli M, Kallio T, Reynaud O, Nasibulin AG, Johans C, Sainio J, Jiang H, Kauppinen EI, Laasonen K (2015) Single-shell carbon-encapsulated iron nanoparticles: synthesis and high electrocatalytic activity for hydrogen evolution reaction. Angew Chem-Int Edit 54:4535–4538. https://doi.org/10.1002/anie.201411450 CrossRefGoogle Scholar
- Wang J, Wang Y, Liu Y, Lv X, Li S, Zhou J, Cao F, Qin G (2018) Facile fabrication of α-Fe2O3/Ag2S heterojunction with enhanced photoelectrochemical water splitting property. J Nanopart Res 20. https://doi.org/10.1007/s11051-018-4328-x
- Warren SC, Voitchovsky K, Dotan H et al (2013) Identifying champion nanostructures for solar water splitting. Nat Mater 12:842–849. https://doi.org/10.1038/nmat368410.1038/NMAT3684
- Ye Y, Zhang H, Chen Y, Deng P, Huang Z, Liu L, Qian Y, Li Y, Li Q (2015) Core–shell structure carbon coated ferric oxide (Fe2O3@C) nanoparticles for supercapacitors with superior electrochemical performance. J Alloy Compd 639:422–427. https://doi.org/10.1016/j.jallcom.2015.03.113 CrossRefGoogle Scholar