Abstract
Photo-induced charge separation and photon absorption play important roles in determining the performance of the photoelectrocatalytic water splitting process. In this work, we utilize dual quantum dots (QDs), consisting of BiVO 4 and carbon, to fabricate a hybrid homojunction-based BiVO 4 photoanode for efficient and stable solar water oxidation. Formation of homojunctions, by decorating as-prepared BiVO 4 substrate with BiVO 4 QDs, enhances the charge separation efficiency by 1.3 times. This enhancement originates from lattice match, which benefits charge transfer across the interface. Furthermore, the use of carbon QDs as a stable photosensitizer effectively extends the photon absorption limit from 520 nm to over 700 nm, yielding an incident photon-to-electron conversion efficiency of 6.0 %, even at 600 nm at 1.23 V versus RHE. Finally, a remarkable photocurrent density of 6.1 mA cm −2 at 1.23 V was recorded after depositing FeOOH/NiOOH as cocatalysts, thereby, reaching 82 % of the theoretical efficiency for BiVO 4 .
Original language | English |
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Pages (from-to) | 1240-1245 |
Number of pages | 6 |
Journal | ChemSusChem |
Volume | 12 |
Issue number | 6 |
DOIs | |
Publication status | Published - 21 Mar 2019 |
Keywords
- BiVO
- carbon quantum dots
- homojunction
- photoanode
- water oxidation
Equipment
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Centre for Electron Microscopy (MCEM)
Peter Miller (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility
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X-ray Platform (MXP)
James Griffith (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility