摘要
S型异质结不但可以提高载流子的分离效率,还可以维持较强的氧化还原能力。因此,构建S型异质是提高光催化二氧化碳还原反应的有效途径。本研究通过静电自组装法构建了具有近红外光响应(>780 nm)的二维BiOBr_(0.5)Cl(0.5)纳米片和一维WO_(3)纳米棒S型异质结光催化剂,并用于高效还原二氧化碳。能带位置和界面电子相互作用的综合分析表明:在光催化二氧化碳还原反应过程中,BiOBr_(0.5)Cl(0.5)/WO_(3)遵循S型电子转移路径;不仅提高了载流子的高效分离,还维持了两相(BiOBr_(0.5)Cl(0.5)和WO_(3))较高的氧化还原能力。此外,二维纳米片/一维纳米棒的结构使得半导体之间具备良好的界面接触,有利于载流子的分离,且暴露更多的活性位点,最终提高催化效率。结果显示,BiOBr_(0.5)Cl(0.5)/WO_(3)异质结催化剂表现出较高的CO_(2)还原能力和CO选择性,CO的产率高达16.68μmol∙g^(−1)∙h^(−1),分别是BiOBr_(0.5)Cl(0.5)的1.7倍和WO_(3)的9.8倍。本工作为构建S型二维/一维异质结光催化剂高效还原二氧化碳提供了新的思路。
Catalytic reduction of CO_(2) to CO has been considered promising for converting the greenhouse gas into chemical intermediates.Compared to other catalytic methods,photocatalytic CO_(2) reduction,which uses solar energy as the energy input,has attracted significant attention because it is a clean and inexhaustible resource.Therefore,using high-performance photocatalysts for effective CO_(2) reduction under mild reaction conditions is an active research hotspot.However,several current photocatalysts suffer from low solar energy conversion efficiency due to the extensive charge recombination and few active sites,leading to low CO_(2) reduction efficiency.Generally,constructing an S-scheme heterojunction can not only promote charge separation but also help maintain strong redox ability.Therefore,the S-scheme heterojunction is expected to help in achieving high conversion activity and CO_(2) reduction efficiency.Here,2D tetragonal BiOBr_(0.5)Cl(0.5) nanosheets and hexagonal WO_(3) nanorods were prepared using a simple hydrothermal synthesis method,and the 2D/1D BiOBr_(0.5)Cl(0.5) nanosheets/WO_(3) nanorods(BiOBr_(0.5)Cl(0.5)/WO_(3))S-scheme heterojunction with near infrared(NIR)light(>780 nm)response were prepared via the electrostatic self-assembly method for the photocatalytic CO_(2)reduction.Following characterization and analysis,including diffuse reflectance spectra(DRS),Mott-Schottky plots,transient photocurrent response,time-resolution photoluminescence spectrum(TRPL),electrochemical impedance spectroscopy(EIS),linear sweep voltammetry(LSV),and electron spin resonance(ESR)measurements,it can be demonstrated that an S-scheme carrier transfer route was formed between the 2D BiOBr_(0.5)Cl(0.5) nanosheets and 1D WO_(3) nanorods.Driven by the internal electric field,which was formed between the two semiconductors,electron migration was boosted,thus inhibiting the recombination of photogenerated carriers,while the stronger redox ability was maintained,thus providing good reduction efficiency over BiOBr_(0.5)Cl(0.5)/WO_(3) composite in CO_(2) reduction.In addition,the 2D/1D nanosheet/nanorod structure allowed for enhanced interface contact with abundant active sites,which favored charge separation and increased photocatalytic activity.Furthermore,the amount of WO_(3) nanorods added during the preparation of the composites was altered,which led to the optimal amount of 5%(w,mass fraction)for the photocatalytic CO_(2)reduction.As a result,the BiOBr_(0.5)Cl(0.5)/WO_(3) composite exhibited superior photocatalytic reduction performance with a CO yield of 16.68μmol·g^(−1)·h^(−1) in the presence of any precious metal cocatalyst or sacrificial agent,which was 1.7 and 9.8 times that of pure BiOBr_(0.5)Cl(0.5)and WO_(3),respectively.In addition,the BiOBr_(0.5)Cl(0.5)/WO_(3)composite provided continuously increased CO yields with excellent selectivity under full-spectrum light irradiation,suggesting good photocatalytic stability.This work describes a novel idea for the construction of 2D/1D S-scheme heterojunction photocatalysts for efficient CO_(2)reduction.
作者
朱弼辰
洪小洋
唐丽永
刘芹芹
唐华
Bichen Zhu;Xiaoyang Hong;Liyong Tang;Qinqin Liu;Hua Tang(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu Province,China;School of Environmental Science and Engineering,Qingdao University,Qingdao 266071,Shandong Province,China)
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2022年第7期45-55,共11页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(21975110,21972058)
山东省泰山青年学者项目资助。
