Zhao Jinlin, Miao Zerui, Zhang Yanfeng, Wen Guangyu, Liu Lihu, Wang Xuxu, Cao Xingzhong, Wang Baoyi
National Experimental Chemistry Teaching Center, Hebei Key Laboratory of Inorganic Nano-materials, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, PR China.
National Experimental Chemistry Teaching Center, Hebei Key Laboratory of Inorganic Nano-materials, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, PR China.
J Colloid Interface Sci. 2021 Jul;593:231-243. doi: 10.1016/j.jcis.2021.02.117. Epub 2021 Mar 9.
Conversion of carbon dioxide into useful chemicals has attracted great attention. However, the significant bottlenecks facing in the field are the poor conversion efficiency of CO and low selectivity of products. Herein, hierarchical BiOBr hollow microspheres are fabricated by a solvothermal method using ethylene glycol (EG) as solvent in presence of polyvinyl pyrrolidone (PVP). The hollow BiOBr microspheres prepared at 120 °C exhibit the best performance for CO photoreduction. The evolution rates of product CO and CH are up to 88.1 µmol gh and 5.8 µmol gh, which are 8.8 times and 5.8 times higher than that of plate-like BiOBr respectively. The hollow microspheres possess larger specific area and generate multiple reflections of light in the cavity, thus enhancing the utilization efficiency of light. The modulated electronic structure by oxygen vacancy (OVs) is beneficial to the transfer of photogenerated electrons and holes. Especially, the enriched charge density of BiOBr by OVs is conductive to the adsorption and activation of CO, which could lower the overall activation energy barrier of CO photoreduction In summary, the synergistic effect of the hollow structure with OVs plays a vital role in boosting the photoreduction of CO for BiOBr. This work provides a new opportunity for designing the high efficiency catalyst by morphology engineering with defects at the atomic level for CO photoreduction.
将二氧化碳转化为有用的化学品已引起了极大关注。然而，该领域面临的重大瓶颈是二氧化碳转化效率低和产物选择性差。在此，以乙二醇（EG）为溶剂，在聚乙烯吡咯烷酮（PVP）存在下，通过溶剂热法制备了分级结构的BiOBr空心微球。在120℃制备的空心BiOBr微球对二氧化碳光还原表现出最佳性能。产物一氧化碳和甲烷的析出速率分别高达88.1 μmol g⁻¹ h⁻¹和5.8 μmol g⁻¹ h⁻¹，分别是片状BiOBr的8.8倍和5.8倍。空心微球具有更大的比表面积，并在腔内产生多次光反射，从而提高了光的利用效率。由氧空位（OVs）调制的电子结构有利于光生电子和空穴的转移。特别是，氧空位使BiOBr的电荷密度富集，有利于一氧化碳的吸附和活化，这可以降低二氧化碳光还原的整体活化能垒。综上所述，空心结构与氧空位的协同作用在促进BiOBr对二氧化碳的光还原中起着至关重要的作用。这项工作为通过原子级缺陷的形貌工程设计用于二氧化碳光还原的高效催化剂提供了新的机会。
