Ge‐Mediated Modification in Ta3N5 Photoelectrodes with Enhanced Charge Transport for Solar Water Splitting |
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| Authors: | Jianyong Feng Dapeng Cao Zhiqiang Wang Wenjun Luo Jiajia Wang Prof. Zhaosheng Li Prof. Zhigang Zou |
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| Affiliation: | National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Ecomaterials and Renewable Energy Research Center, Nanjing University, 22 Hankou Road, Nanjing 210093 (P.R. China) |
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| Abstract: | Ta3N5 is a promising photoanode candidate for photoelectrochemical water splitting, with a band gap of about 2.1 eV and a theoretical solar‐to‐hydrogen efficiency as high as 15.9 % under AM 1.5 G 100 mW cm?2 irradiation. However, the presently achieved highest photocurrent (ca. 7.5 mA cm?2) on Ta3N5 photoelectrodes under AM 1.5 G 100 mW cm?2 is far from the theoretical maximum (ca. 12.9 mA cm?2), which is possibly due to serious bulk recombination (poor bulk charge transport and charge separation) in Ta3N5 photoelectrodes. In this study, we show that volatilization of intentionally added Ge (5 %) during the synthesis of Ta3N5 promotes the electron transport and thereby improves the charge‐separation efficiency in bulk Ta3N5 photoanode, which affords a 320 % increase of the highest photocurrent comparing with that of pure Ta3N5 photoanode under AM 1.5 G 100 mW cm?2 simulated sunlight. |
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| Keywords: | charge transfer electron transport energy conversion photochemistry tantalum nitride |
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