Gan Xiaoyu, Zheng Ruijin, Liu Tianlin, Meng Jiao, Chen Ruiping, Sun Xuan, Sun Xun
Key Laboratory for Colloid & Interface Chemistry, Shandong University, Education Ministry, Jinan, 250100, P.R. China.
Key Laboratory of Functional Crystal Materials and Device, Shandong University, Ministry of Education, Jinan, 250100, P.R. China.
Chemistry. 2017 May 29;23(30):7264-7271. doi: 10.1002/chem.201605576. Epub 2017 Mar 30.
As an excellent n-type semiconductor, indium oxide (In O ) is also a good candidate for photocatalysis such as light-induced water splitting. However, the efficiency of the oxygen evolution reaction (OER) underperforms in view of the wide band gap (BG) and fast charge recombination in In O . N-doping provides a sound method to narrow the BG and to prohibit the charge recombination by forming new energy levels between the valence band (VB) and the conduction band (CB). In this work, an In-based organic framework sod-ZMOF was used as a precursor to prepare the N-doped In O . After calcination, sod-ZMOF is transformed into N-doped In O nanocrystalline, in which the ligand within sod-ZMOF serves as the nitrogen source. In addition, sod-ZMOF acts as self-template during calcination to generate abundant nanopores within the In O frameworks, providing large specific surface area and active sites for OER. The BG is narrowed to 2.9 from 3.7 eV of the pure In O on account of the N-doping. N species are doped in both the substitutional and interstitial fashion, and the interstitial doping is believed to improve the photo-induced carrier separation by the formation of oxygen vacancies. As a consequence, the overpotential for OER is effectively decreased from the pure In O , and the electrocatalytic experiment proves superior catalytic activity with a high current density and long-term durability compared to the In O nanoparticles obtained from In(OH) .
作为一种优秀的n型半导体，氧化铟（In₂O₃）也是光催化（如光致水分解）的良好候选材料。然而，鉴于In₂O₃的宽带隙（BG）和快速的电荷复合，析氧反应（OER）的效率表现不佳。氮掺杂提供了一种合理的方法来缩小带隙，并通过在价带（VB）和导带（CB）之间形成新的能级来抑制电荷复合。在这项工作中，一种基于铟的有机框架sod-ZMOF被用作前驱体来制备氮掺杂的In₂O₃。煅烧后，sod-ZMOF转变为氮掺杂的In₂O₃纳米晶体，其中sod-ZMOF中的配体作为氮源。此外，sod-ZMOF在煅烧过程中充当自模板，在In₂O₃框架内产生大量纳米孔，为OER提供大的比表面积和活性位点。由于氮掺杂，带隙从纯In₂O₃的3.7 eV缩小到2.9。氮物种以替代和间隙两种方式掺杂，并且间隙掺杂被认为通过形成氧空位来改善光生载流子的分离。结果，与纯In₂O₃相比，OER的过电位有效降低，并且电催化实验证明与由In(OH)₃获得的In₂O₃纳米颗粒相比，具有更高的电流密度和长期耐久性的优异催化活性。
