Superior NOx photocatalytic removal over hybrid hierarchical Bi/BiOI with high non-NO2 selectivity: synergistic effect of oxygen vacancies and bismuth nanoparticles
Superior NOx photocatalytic removal over hybrid hierarchical Bi/BiOI with high non-NO2 selectivity: synergistic effect of oxygen vacancies and bismuth nanoparticles
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DOI：
10.1039/c8cy01466c
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发表时间：
2018-10
影响因子：
5
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中科院分区：
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为了实现一种有效的光催化剂用于NO污染控制，丰富的氧空位和金属铋（Bi）纳米粒子同时引入到三维分层BiOI通过原位自还原与含水硼氢化钠。与原始BiOI相比，所获得的20-Bi/BiOI表现出上级NOx（NO和NO2）去除效率以及对非NO2的高选择性。经过仔细分析各种表征结果，发现这种增强归因于由氧空位形成的浅施主和Bi纳米颗粒的表面等离子体共振（SPR）效应的协同结果，这两者都有助于促进光捕获和抑制光生电荷载流子的复合。此外，氧空位可以改善NO吸附，与NO2强烈联合收割机结合，并促进stecOH和stecO 2 −自由基的形成，促进NOx（NO和NO2）深度氧化为NO2−和NO3−，离子色谱法的结果有力地证明了这一点。总的来说，这项工作突出了Bi和氧空位通过自还原策略引入的协同效应，并为解决NO污染开辟了有效途径。
To achieve an efficient photocatalyst for NO pollution control, abundant oxygen vacancies and metallic bismuth (Bi) nanoparticles were simultaneously introduced into three-dimensional hierarchal BiOI via in situ self-reduction with aqueous NaBH4. The obtained 20-Bi/BiOI exhibited superior NOx (NO and NO2) removal efficiency with high selectivity for non-NO2, compared to pristine BiOI. After careful analysis of various characterization results, it was found that such an enhancement was attributed to the synergistic results of shallow donors formed by oxygen vacancies and the surface plasmonic resonance (SPR) effect of Bi nanoparticles, both of which contributed to the promotion of light harvesting and the suppression of the recombination of photoinduced charge carriers. What's more, oxygen vacancies can improve NO adsorption, strongly combine with NO2, and facilitate the formation of ˙OH and ˙O2− radicals, promoting the deep oxidation of NOx (NO and NO2) to NO2− and NO3−, robustly evidenced by the results of ion chromatography. Overall, this work highlights the synergistic effects of Bi and oxygen vacancies introduced by a self-reduction strategy and opens up an effective avenue for addressing NO pollution.