Synergetic effect of oxygen vacancies coupled with in-situ Bi clusters in Bi2WO6 for enhancing photocatalytic CO2 reduction
Synergetic effect of oxygen vacancies coupled with in-situ Bi clusters in Bi2WO6 for enhancing photocatalytic CO2 reduction
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DOI：
10.1016/j.apsusc.2023.156530
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发表时间：
2023-01
影响因子：
6.7
通讯作者：
Zhe Sun;Tianwu Liu;Qianqian Shen;Huimin Li;Xuguang Liu;H. Jia;J. Xue
中科院分区：
文献类型：
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作者：
Zhe Sun;Tianwu Liu;Qianqian Shen;Huimin Li;Xuguang Liu;H. Jia;J. Xue
为了提高光催化性能，采用温和铝热还原法制备了具有氧空位（Vo）和原位负载Bi团簇的Bi 2 WO 6（BWO）。从形貌和结构特征可以看出，随着退火温度的升高，Bi团簇由于氧空位而逐渐从BWO表面析出。450 ℃退火处理的Bi-Vo-BWO-450光催化剂表现出最好的光催化还原CO2性能，CO和CH 4的生成速率分别达到5.94和1.18 μmol·g−1·h−1。实验分析和第一性原理计算表明，原位Bi团簇表现出独特的表面等离子体共振（SPR）效应，并通过Bi与BWO之间的肖特基势垒诱导形成内电场，增强了光催化剂的光吸收，提高了电荷分离和转移效率。同时，Bi团簇作为表面活性位，活化CO2吸附，降低光催化还原CO2的限速势垒，并通过阻止含氧基团吸附在氧缺陷位，提高氧空位的活性.这一工作对Bi团簇与氧空位之间的协同效应有了清晰的认识，为高效催化剂的研究提供了新的启示。
In order to improve photocatalytic performance, Bi2WO6(BWO) with oxygen vacancies (Vo) and in-situ loaded Bi clusters was prepared by using mild aluminothermic reduction. From morphological and structural characterization, it can be seen that Bi clusters gradually precipitates from the surface of BWO owing to oxygen vacancies as annealing temperature increases. The photocatalyst annealed at 450 ℃ (Bi-Vo-BWO-450) demonstrates the best photocatalytic CO2reduction performance with CO and CH4production rate reaching 5.94 and 1.18 µmol·g−1·h−1, respectively. From experimental analyses and first principles calculation, in-situ Bi clusters exhibit the unique surface plasma resonance (SPR) effect and induce the formation of internal electric field by Schottky barrier between Bi and BWO, which enhance the light absorption of photocatalyst and improve charge separation and transfer efficiency. Meanwhile, Bi clusters act as the surface active sites to activate CO2adsorption for reducing the rate-limiting potential barrier in photocatalytic CO2reduction, and improve the activity of oxygen vacancies by preventing the oxygen-containing groups from being adsorbed at the oxygen defect site. This work has a clear understanding of the synergetic effect between Bi clusters and oxygen vacancies, and provides a new enlightenment into high-efficiency catalyst.