Kim Sarang, Oh Dongrak, Jang Ji-Wook
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
Graduate School of Carbon Neutrality, UNIST, Ulsan 44919, Republic of Korea.
Nano Lett. 2024 May 1;24(17):5146-5153. doi: 10.1021/acs.nanolett.3c05136. Epub 2024 Mar 25.
Photoelectrochemical (PEC) HO production via two-electron O reduction is promising for HO production without emitting CO. For PEC HO production, α-FeO is an ideal semiconductor owing to its earth abundance, superior stability in water, and an appropriate band gap for efficient solar light utilization. Moreover, its conduction band is suitable for O reduction to produce HO. However, a significant overpotential for water oxidation is required due to the poor surface properties of α-FeO. Thus, unassisted solar HO production is not yet possible. Herein, we demonstrate unassisted PEC HO production using α-FeO for the first time by applying glycerol oxidation, which requires less bias compared with water oxidation. We obtain maximum Faradaic efficiencies of 96.89 ± 0.6% and 100% for glycerol oxidation and HO production, respectively, with high stability for 25 h. Our results indicate that unassisted and stable PEC HO production is feasible with glycerol valorization using the α-FeO photoanode.
通过双电子氧还原进行光电化学（PEC）产过氧化氢有望在不排放二氧化碳的情况下生产过氧化氢。对于PEC产过氧化氢而言，α-FeO是一种理想的半导体，因其在地壳中储量丰富、在水中具有卓越的稳定性以及具有适合高效利用太阳光的带隙。此外，其导带适合氧还原以产生过氧化氢。然而，由于α-FeO表面性质较差，水氧化需要显著的过电位。因此，无辅助的太阳能产过氧化氢目前尚不可能实现。在此，我们首次通过应用甘油氧化展示了使用α-FeO进行无辅助PEC产过氧化氢，与水氧化相比，甘油氧化所需的偏压较小。我们分别获得了96.89±0.6%和100%的甘油氧化和产过氧化氢的最大法拉第效率，并在25小时内具有高稳定性。我们的结果表明，使用α-FeO光阳极通过甘油增值实现无辅助且稳定的PEC产过氧化氢是可行的。
