Lin Yue, Zhihao Zeng, Xujie Ren, Shude Yuan, Chuanqi Xia, Xin Hu, Leihong Zhao, Lvchao Zhuang, Yiming He
{"title":"Enhanced photocatalytic N2 fixation using KNbO3/Bi4O5Br2 type II heterojunction","authors":"Lin Yue, Zhihao Zeng, Xujie Ren, Shude Yuan, Chuanqi Xia, Xin Hu, Leihong Zhao, Lvchao Zhuang, Yiming He","doi":"10.1007/s11705-024-2424-2","DOIUrl":null,"url":null,"abstract":"<div><p>The fabrication of heterojunction catalysts is an effective strategy to enhance charge separation efficiency, thus boosting the performance of photocatalysts. This work presents the synthesis and investigation of a novel KNbO<sub>3</sub>/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> heterostructure catalyst for photocatalytic N<sub>2</sub>–to–NH<sub>3</sub> conversion under light illumination. While morphology analysis revealed KNbO<sub>3</sub> microcubes embedded within Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> nanosheets, the composite exhibited no significant improvement in specific surface area or optical property compared to Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> due to the relatively wide band gap and low surface area of KNbO<sub>3</sub>. The main contribution lies in the enhanced separation efficiency of photogenerated electrons and holes. Besides, the band structure analysis suggests that KNbO<sub>3</sub> and Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> exhibit suitable band potentials to form a type II heterojunction. Benefiting from the higher Fermi level of KNbO<sub>3</sub> than Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>, the electron drift at the contact region thus occurs and leads to the formation of a built-in electric field with the direction from KNbO<sub>3</sub> to Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>, accelerating electron migration and improving the operational efficiency of the photocatalysts. Consequently, the KNbO<sub>3</sub>/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub> catalyst shows an increased photoactivity, achieving an NH<sub>3</sub> generation rate 1.78 and 1.58 times those of KNbO<sub>3</sub> and Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>, respectively. This work may offer valuable insights for the design and synthesis of heterojunction composite photocatalysts.\n</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":571,"journal":{"name":"Frontiers of Chemical Science and Engineering","volume":"18 6","pages":""},"PeriodicalIF":4.3000,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Chemical Science and Engineering","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11705-024-2424-2","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The fabrication of heterojunction catalysts is an effective strategy to enhance charge separation efficiency, thus boosting the performance of photocatalysts. This work presents the synthesis and investigation of a novel KNbO3/Bi4O5Br2 heterostructure catalyst for photocatalytic N2–to–NH3 conversion under light illumination. While morphology analysis revealed KNbO3 microcubes embedded within Bi4O5Br2 nanosheets, the composite exhibited no significant improvement in specific surface area or optical property compared to Bi4O5Br2 due to the relatively wide band gap and low surface area of KNbO3. The main contribution lies in the enhanced separation efficiency of photogenerated electrons and holes. Besides, the band structure analysis suggests that KNbO3 and Bi4O5Br2 exhibit suitable band potentials to form a type II heterojunction. Benefiting from the higher Fermi level of KNbO3 than Bi4O5Br2, the electron drift at the contact region thus occurs and leads to the formation of a built-in electric field with the direction from KNbO3 to Bi4O5Br2, accelerating electron migration and improving the operational efficiency of the photocatalysts. Consequently, the KNbO3/Bi4O5Br2 catalyst shows an increased photoactivity, achieving an NH3 generation rate 1.78 and 1.58 times those of KNbO3 and Bi4O5Br2, respectively. This work may offer valuable insights for the design and synthesis of heterojunction composite photocatalysts.
期刊介绍:
Frontiers of Chemical Science and Engineering presents the latest developments in chemical science and engineering, emphasizing emerging and multidisciplinary fields and international trends in research and development. The journal promotes communication and exchange between scientists all over the world. The contents include original reviews, research papers and short communications. Coverage includes catalysis and reaction engineering, clean energy, functional material, nanotechnology and nanoscience, biomaterials and biotechnology, particle technology and multiphase processing, separation science and technology, sustainable technologies and green processing.