In Situ Imaging of Catalytic Reactions on Tungsten Oxide Nanowires Connects Surface–Ligand Redox Chemistry with Photocatalytic Activity
In Situ Imaging of Catalytic Reactions on Tungsten Oxide Nanowires Connects Surface–Ligand Redox Chemistry with Photocatalytic Activity
复制标题
氧化钨纳米线上催化反应的原位成像将表面配体氧化还原化学与光催化活性连接起来
DOI：
10.1021/acs.nanolett.2c00674
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发表时间：
2022
期刊：
影响因子：
10.8
通讯作者：
Sadtler, Bryce
中科院分区：
文献类型：
--
作者：
Shen, Meikun;Ding, Tianben;Tan, Che;Rackers, William H.;Zhang, Dongyan;Lew, Matthew D.;Sadtler, Bryce
半导体纳米晶体是通过光催化产生化学原料的有希望的候选者。由于纳米晶体表面的复杂性和异质性，了解用于制备胶体纳米晶体的配体在催化中的作用具有挑战性。我们使用原位分子荧光成像来绘制抗坏血酸功能化之前和之后沿着单个氧化钨纳米线的活性区域的空间分布。我们观察到用抗坏血酸处理后光催化水氧化活性显着增强，而不是阻塞活性位点。虽然初始纳米线包含沿其长度分散的非活性区域，但功能化纳米线的光催化活性表现出高度均匀性。活性区域与其表面化学性质的空间共定位表明，光催化过程中抗坏血酸的氧化会沿着纳米线表面产生新的氧空位。我们证明，在光催化过程中控制表面配体氧化还原化学可以提高纳米晶体催化剂上的活性位点浓度。
Semiconductor nanocrystals are promising candidates for generating chemical feedstocks through photocatalysis. Understanding the role of ligands used to prepare colloidal nanocrystals in catalysis is challenging due to the complexity and heterogeneity of nanocrystal surfaces. We usein situsingle-molecule fluorescence imaging to map the spatial distribution of active regions along individual tungsten oxide nanowires before and after functionalizing them with ascorbic acid. Rather than blocking active sites, we observed a significant enhancement in activity for photocatalytic water oxidation after treatment with ascorbic acid. While the initial nanowires contain inactive regions dispersed along their length, the functionalized nanowires show high uniformity in their photocatalytic activity. Spatial colocalization of the active regions with their surface chemical properties shows that oxidation of ascorbic acid during photocatalysis generates new oxygen vacancies along the nanowire surface. We demonstrate that controlling surface–ligand redox chemistry during photocatalysis can enhance the active site concentration on nanocrystal catalysts.