Layered Perovskite Oxyiodide with Narrow Band Gap and Long Lifetime Carriers for Water Splitting Photocatalysis
Layered Perovskite Oxyiodide with Narrow Band Gap and Long Lifetime Carriers for Water Splitting Photocatalysis
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具有窄带隙和长寿命载流子的层状钙钛矿氧碘化物用于水分解光催化
DOI：
10.1021/jacs.1c02763
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发表时间：
2021
影响因子：
15
通讯作者：
Abe Ryu
中科院分区：
文献类型：
--
作者：
Ogawa Kanta;Suzuki Hajime;Zhong Chengchao;Sakamoto Ryota;Tomita Osamu;Saeki Akinori;Kageyama Hiroshi;Abe Ryu
开发具有窄带隙和高稳定性的半导体对于实现太阳能到化学能的转换至关重要。具有高极化率的碘化合物由于其窄的带隙和长的载流子寿命而引起关注，如卤化物钙钛矿太阳能电池所代表的;然而，它们被认为不适合苛刻的光催化水分解，因为碘易于自氧化。在这里，我们证明了Ba 2Bi 3 Nb 2 O 11 I，一种层状的Sillén-Aurivillius碘氧化物，不仅比其氯化物和溴化物对应物具有更宽的可见光范围，而且还可以作为稳定的光催化剂，有效地氧化水。密度泛函理论计算表明，在钙钛矿块，而不是萤石Bi 2 O2块中的氧2 p轨道如前所述，有害地推高价带最大值，这可以解释为一个修改的马德隆势分析，考虑到碘的高极化率。此外，高度可极化的碘化物有助于Ba 2Bi 3 Nb 2 O 11 I的更长的载流子寿命，从而允许比其氯化物和溴化物对应物显著更高的量子效率。首次在碘基体系中以Ba 2Bi 3 Nb 2 O 11 I为析氧光催化剂实现了可见光驱动的Z型水分解。本研究提供了一种新的方法，将可极化的“软”阴离子到层状材料的构建块中，以操纵能带结构并改善可见光响应功能的载流子动力学。
The development of semiconductors with narrow band gap and high stability is crucial for achieving solar to chemical energy conversion. Compounds with iodine, which has a high polarizability, have attracted attention because of their narrow band gap and long carrier lifetime, as typified by halide perovskite solar cells; however, they have been regarded as unsuitable for harsh photocatalytic water splitting because iodine is prone to self-oxidation. Here, we demonstrate that Ba2Bi3Nb2O11I, a layered Sillén–Aurivillius oxyiodide, not only has access to a wider range of visible light than its chloride and bromide counterparts, but also functions as a stable photocatalyst, efficiently oxidizing water. Density functional theory calculations reveal that the oxygen 2p orbitals in the perovskite block, rather than the fluorite Bi2O2block as previously pointed out, anomalously push up the valence band maximum, which can be explained by a modified Madelung potential analysis that takes into account the high polarizability of iodine. In addition, the highly polarizable iodide contributes to longer carrier lifetime of Ba2Bi3Nb2O11I, allowing for a significantly higher quantum efficiency than its chloride and bromide counterparts. Visible-light-driven Z-scheme water splitting was achieved for the first time in an iodine-based system using Ba2Bi3Nb2O11I as an oxygen-evolution photocatalyst. The present study provides a novel approach for incorporating polarizable “soft” anions into building blocks of layered materials to manipulate the band structure and improve the carrier dynamics for visible-light responsive functions.