Antioxidative Stannous Oxalate Derived Lead-Free Stable CsSnX3 (X=Cl, Br, and I) Perovskite Nanocrystals
Antioxidative Stannous Oxalate Derived Lead-Free Stable CsSnX3 (X=Cl, Br, and I) Perovskite Nanocrystals
复制标题
抗氧化草酸亚锡衍生的无铅稳定 CsSnX3（X=Cl、Br 和 I）钙钛矿纳米晶体
DOI：
10.1002/anie.202011569
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发表时间：
2020-11-03
影响因子：
16.6
通讯作者：
Zhong, Xinhua
中科院分区：
文献类型：
--
作者：
Kang, Cuiting;Rao, Huashang;Zhong, Xinhua
无铅的CsSnX 3钙钛矿NC正成为CsPbX 3（X=Cl、Br、I）的有前途的替代品，但具有极差的稳定性。在此，我们强调了合成中使用的Sn-II前体对所得CsSnX 3 NC的稳定性的显著影响。提出了一种使用Cs2 CO 3、SnC 2 O 4和NH 4X作为相应的组分前体来合成CsSnX 3 NCs的方法，其中反应物的比例可以容易地调节。使用抗氧化剂SnC_2O_4作为Sn-II前驱体可以得到稳定的CsSnX_3纳米粒子。实验结果表明，SnC_2O_4前驱体中草酸盐的加入是提高纳米晶稳定性的主要原因。草酸根离子具有很强的抗氧化能力，能有效抑制Sn-II在合成过程中的氧化。此外，草酸根作为双齿封端配体被证明是在形成的NC表面上的配位。这不仅可以钝化表面上未配位的Sn，而且可以防止NC的氧化。
Lead-free CsSnX3 perovskite NCs are becoming a promising alternative to CsPbX3 (X=Cl, Br, I), but suffer from extremely poor stability. Herein, we highlight the significant effect of Sn-II precursors used in the synthesis on the stability of the resultant CsSnX3 NCs. A method is proposed for synthesizing CsSnX3 NCs using Cs2CO3, SnC2O4, and NH4X as corresponding constituent precursors, wherein the ratio of reactants can be easily adjusted. Stable CsSnX3 NCs can be obtained with the use of antioxidative SnC2O4 as the Sn-II precursor. Experimental results show that the improvement of NCs stability is mainly ascribed to the role of oxalate in the SnC2O4 precursor. Oxalate ion has a strong antioxidative ability and can effectively inhibit the oxidation of Sn-II during the synthesis. Besides, oxalate as a bidentate capping ligand is shown to be coordinated on the surface of formed NCs. This can not only passivate the uncoordinated Sn on the surface but also prevent the oxidation of the NCs.