Single-Atom Iridium on Hematite Photoanodes for Solar Water Splitting: Catalyst or Spectator?
Single-Atom Iridium on Hematite Photoanodes for Solar Water Splitting: Catalyst or Spectator?
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在赤铁矿光阳极上进行太阳能水分裂的单原子虹膜：催化剂还是观众？
DOI：
10.1021/jacs.2c09974
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发表时间：
2023-01-25
影响因子：
15
通讯作者：
Sobrido, Ana Belen Jorge
中科院分区：
文献类型：
--
作者：
Guo, Qian;Zhao, Qi;Crespo-Otero, Rachel;Di Tommaso, Devis;Tang, Junwang;Dimitrov, Stoichko D.;Titirici, Maria-Magdalena;Li, Xuanhua;Sobrido, Ana Belen Jorge
赤铁矿光阳极上的单原子催化剂（SAC）是提高光电化学性能的有效助催化剂。它们具有高原子利用率、显著的活性和独特的活性位点。然而，SAC在赤铁矿光阳极上的具体作用尚未完全了解：SAC是作为催化位点还是作为旁观者？通过光谱实验和计算机模拟相结合的方法，我们证明了在赤铁矿（α-Fe 2 O3/sIr）光阳极上的单原子铱（sIr）催化剂作为一种真正的催化剂，通过捕获来自赤铁矿的空穴并为水的氧化反应提供活性位点。原位瞬态吸收光谱表明，减少了孔的数量和缩短的空穴寿命中存在的硅铱。这在第二个时间尺度上特别明显，表明空穴向水氧化的快速转移和耗尽。强度调制光电流谱表明，与裸α-Fe 2 O3相比，α-Fe 2 O3/siIr/电解质界面的空穴传输速度更快。密度泛函理论计算揭示了水氧化的机制，使用铱作为催化中心是首选的途径，因为它显示出较低的起始电位比Fe网站。X射线光电子能谱分析表明，SiR引入了一个中间带隙4d态，这是空穴快速传输和空穴耗尽的关键。这些综合结果为控制太阳能水氧化的过程以及SAC在增强半导体在光辅助反应中的催化性能方面的作用提供了新的见解。
Single-atom catalysts (SACs) on hematite photoanodes are efficient cocatalysts to boost photoelectrochemical performance. They feature high atom utilization, remarkable activity, and distinct active sites. However, the specific role of SACs on hematite photoanodes is not fully understood yet: Do SACs behave as a catalytic site or as a spectator? By combining spectroscopic experiments and computer simulations, we demonstrate that single-atom iridium (sIr) catalysts on hematite (α-Fe2O3/sIr) photoanodes act as a true catalyst by trapping holes from hematite and providing active sites for the water oxidation reaction. In situ transient absorption spectroscopy showed a reduced number of holes and shortened hole lifetime in the presence of sIr. This was particularly evident on the second timescale, indicative of fast hole transfer and depletion toward water oxidation. Intensity-modulated photocurrent spectroscopy evidenced a faster hole transfer at the α-Fe2O3/sIr/electrolyte interface compared to that at bare α-Fe2O3. Density functional theory calculations revealed the mechanism for water oxidation using sIr as a catalytic center to be the preferred pathway as it displayed a lower onset potential than the Fe sites. X-ray photoelectron spectroscopy demonstrated that sIr introduced a mid-gap of 4d state, key to the fast hole transfer and hole depletion. These combined results provide new insights into the processes controlling solar water oxidation and the role of SACs in enhancing the catalytic performance of semiconductors in photo-assisted reactions.
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影响因子：
16.6
作者：
Sheehan SW;Thomsen JM;Hintermair U;Crabtree RH;Brudvig GW;Schmuttenmaer CA
通讯作者：
Schmuttenmaer CA
影响因子：
3.7
作者：
Pina, Joao;Dias, Paula;Seixas de Melo, Joao Sergio
通讯作者：
Seixas de Melo, Joao Sergio
在赤铁矿光电极中极性缺陷状态的费米水平偏移的局限性。
影响因子：
16.6
作者：
Lohaus C;Klein A;Jaegermann W
通讯作者：
Jaegermann W
通过氧化铁和硅实现无辅助太阳能分解水
影响因子：
16.6
作者：
Jang, Ji-Wook;Du, Chun;Ye, Yifan;Lin, Yongjing;Yao, Xiahui;Thorne, James;Liu, Erik;McMahon, Gregory;Zhu, Junfa;Javey, Ali;Guo, Jinghua;Wang, Dunwei
通讯作者：
Wang, Dunwei
影响因子：
15
作者：
Kay, Andreas;Cesar, Ilkay;Graetzel, Michael
通讯作者：
Graetzel, Michael