Earth-abundant iron(iii) species serves as a cocatalyst boosting the multielectron reduction of IO3－/I－ redox shuttle in Z-scheme photocatalytic water splitting
Earth-abundant iron(iii) species serves as a cocatalyst boosting the multielectron reduction of IO3－/I－ redox shuttle in Z-scheme photocatalytic water splitting
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地球丰富的铁(iii)物种作为助催化剂促进Z型光催化水分解中IO3－/I－氧化还原穿梭的多电子还原
DOI：
10.1039/d1ta01703a
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发表时间：
2021
影响因子：
11.9
通讯作者：
Ryu Abe
中科院分区：
文献类型：
--
作者：
Katsuya Murofushi;Kanta Ogawa;Hajime Suzuki;Ryota Sakamoto;Osamu Tomita;Kosuke Kato;Akira Yamakata;Akinori Saeki;Ryu Abe
在可见光照射下，z -方案水分解在实际应用中具有很大的潜力。该系统包括两个用于O2和H2演化的光催化剂，以及用于在这些光催化剂之间传递电子的氧化还原穿梭子。因此，促进梭子的氧化还原反应对高效分解水起着至关重要的作用。特别是，对于多电子氧化还原反应（例如，IO3−/I−），辅助催化剂是必不可少的，其中迄今为止只有贵金属可能起作用。在此，我们证明了FeOx催化Bi4TaO8Cl光催化剂上的多电子IO3−还原。由于缺乏多电子还原能力，裸Bi4TaO8Cl不能从IO3−水溶液中析出O2，而负载FeOx则可以析出O2。通过一系列的实验研究，如时间分辨光谱，我们阐明了O2演化增强是由于FeOx促进了IO3−的多电子还原。负载FeOx中的FeIII/FeII氧化还原对有利于从Bi4TaO8Cl中捕获电子载流子和还原氧化还原介质。此外，FeOx对其他光催化剂和氧化还原介质也是有效的。据我们所知，所开发的助催化剂是地球上第一个丰富的多电子氧化还原介质的助催化剂。
Z-scheme water splitting has exhibited significant potential for practical water splitting under visible light irradiation. This system comprises two photocatalysts for O2 and H2 evolution, along with a redox shuttle for transporting electrons between these photocatalysts. Therefore, the promotion of redox reaction of the shuttle play a crucial role in efficient water splitting. In particular, for multielectron redox reactions (e.g., IO3−/I−), a cocatalyst is indispensable, where only noble metals may contribute thus far. Herein, we demonstrate that FeOx catalyzes the multielectron IO3− reduction on the Bi4TaO8Cl photocatalyst. While bare Bi4TaO8Cl does not show O2 evolution from an aqueous IO3− solution because of the lack of multielectron reduction ability, FeOx loading enables O2 evolution. Based on a series of experimental investigations, such as time-resolved spectroscopy, we elucidated that the O2 evolution enhancement stems from the promotion of multielectron reduction of IO3− by FeOx. The FeIII/FeII redox couple in the loaded FeOx facilitates both electron carrier capture from Bi4TaO8Cl and reduction of the redox mediator. In addition, FeOx is effective for other photocatalysts and redox mediators. To the best of our knowledge, the developed cocatalysts is the first earth-abundant cocatalyst for multielectron redox mediators.