Abstract
Photoelectrochemical water splitting using solar energy is a highly promising technology to produce hydrogen as an environmentally friendly and renewable fuel with high-energy density. This approach requires the development of appropriate photoelectrode materials and substrates, which are low-cost and applicable for the fabrication of large area electrodes. In this work, hematite photoelectrodes are grown by aerosol assisted chemical vapour deposition (AA-CVD) onto highly-conductive and bulk porous SnO2 (Sb-doped) ceramic substrates. For such photoelectrodes, the photocurrent density of 2.8 mA cm-2 is achieved in aqueous 0.1 M NaOH under blue LED illumination (λ = 455 nm; 198 mW cm-2) at 1.23 V vs. RHE (reversible hydrogen electrode). This relatively good photoelectrochemical performance of the photoelectrode is achieved despite the simple fabrication process. Good performance is suggested to be related to the three-dimensional morphology of the porous ceramic substrate resulting in excellent light-driven charge carrier harvesting. The porosity of the ceramic substrate allows growth of the photoactive layer (SnO2-grains covered by hematite) to a depth of some micrometers, whereas the thickness of Fe2O3-coating on individual grains is only about 100–150 nm. This architecture of the photoactive layer assures a good light absorption and it creates favourable conditions for charge separation and transport.
Original language | English |
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Pages (from-to) | 19667-19675 |
Number of pages | 9 |
Journal | International Journal of Hydrogen Energy |
Volume | 44 |
Issue number | 36 |
Early online date | 5 Jul 2019 |
DOIs | |
Publication status | Published - 26 Jul 2019 |
Funding
The authors thank Prof. L. Peter for discussion and support. This study was supported by the CONACYT-México (projects #280373 , #A1-S-20353 and #259705 ) and funding from the PRODEP by project number UTMIX-PTC-054 to assemble AA-CVD system. This support is gratefully acknowledged. The authors are grateful to Dr. Erick Adrián Juárez Arellano for his help with X-ray analysis.
Keywords
- Ceramics
- Hematite
- Photoanode
- Solar energy
- Water splitting
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology