S型CeO_(2)/Bi_(2)MoO_(6)微球异质结的理性设计及其高效光催化CO_(2)还原  

Rational Design of S-Scheme CeO_(2)/Bi_(2)MoO_(6) Microsphere Heterojunction for Efficient Photocatalytic CO_(2) Reduction

作　　者：许修涛 邵春风 张金锋[1] 王中辽 代凯[1] Xiutao Xu;Chunfeng Shao;Jinfeng Zhang;Zhongliao Wang;Kai Dai(Laboratory of Green and Precise Synthetic Chemistry and Applications,Ministry of Education,Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation,Anhui Province Key Laboratory of Intelligent Computing and Applications,Anhui Province Industrial Generic Technology Research Center for Alumics Materials,Huaibei Normal University,Huaibei 235000,Anhui Province,China)

机构地区：[1]淮北师范大学,绿色和精准合成化学及应用教育部重点实验室、污染物敏感材料与环境修复安徽省重点实验室、智能计算及应用安徽省重点实验室和安徽省陶铝新材料产业共性技术研究中心,安徽淮北235000

出　　处：《物理化学学报》2024年第10期39-42,共4页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(22278169,51973078);安徽省高校优秀科研创新团队(2022AH010028);安徽省教育厅重大项目(2022AH040068);安徽省教育厅重点项目(2022AH050396,2022AH050376);安徽省质量工程项目(2022sx134)。

摘　　要：人工半导体光催化CO_(2)转化被广泛认为是模拟自然碳循环的最有前途的策略之一。其中,Bi_(2)MoO_(6)具有光催化CO_(2)转化的潜力。然而,由于其光生电荷载体的快速复合,其催化性能仍然不足。因此,改善Bi_(2)MoO_(6)的催化效率是一个紧迫的问题。在这项研究中,我们通过水热法合成了Bi_(2)MoO_(6)纳米片,并在其表面同时生长了CeO_(2)纳米颗粒,形成了Ce^(3+)/Ce^(4+)离子桥接修饰的S型异质结。时间分辨光致发光光谱和光电化学测试揭示了这种异质结的增强电荷分离效应。此外,原位X射线光电子能谱分析和理论计算进一步证实,光生电子转移路径遵循S型机制,从氧化型半导体Bi_(2)MoO_(6)的导带转移到还原型半导体CeO_(2)的价带。实验结果表明,CeO_(2)/Bi_(2)MoO_(6)、Bi_(2)MoO_(6)和CeO_(2)的光催化CO_(2)还原为CO的效率分别为65.3、14.8和1.2μmol·g^(-1)·h^(-1)。与纯Bi_(2)MoO_(6)相比,CeO_(2)/Bi_(2)MoO_(6)复合催化剂将CO_(2)光催化还原为CO的催化效率提高了3.12倍。这项工作为设计和构建新型S型异质结光催化剂提供了独特的见解。In the pursuit of efficient photocatalytic carbon dioxide(CO_(2))conversion,the use of artificial semiconductors powered by solar energy offers great potential for simulating natural carbon cycling.However,the efficiency of photocatalytic CO_(2) conversion remains suboptimal,primarily due to inadequate separation of photogenerated charges,which hinders the performance of semiconductor-based CO_(2) reduction.Consequently,recent research efforts have focused on identifying ideal materials for CO_(2) photocatalytic conversion.Among the candidate materials,the structure of Bi_(2)MoO_(6) consists of alternating layers of(Bi_(2)O_(2))2+and perovskite-like(MoO4)2-layers with shared oxygen atoms between them.This inherent charge distribution within Bi_(2)MoO_(6) creates an inhomogeneous electric field,facilitating the efficient separation of photogenerated charge carriers.The morphology and structure of a catalyst significantly influence the rate of recombination of photogenerated charge carriers.Research has shown that ultrathin Bi_(2)MoO_(6) nanosheets,compared to other 2D and 3D structures of Bi_(2)MoO_(6) materials,possess longer fluorescence lifetimes,providing more opportunities for the separation of photogenerated charge carriers.However,Bi_(2)MoO_(6) still exhibits relatively low catalytic efficiency due to its insufficiently negative conduction band position(ranging between-0.2 and-0.4 V).To address this limitation,a viable strategy is to load a semiconductor with a more negatively positioned conduction band onto Bi_(2)MoO_(6),creating an S-scheme heterojunction.In this study,Bi_(2)MoO_(6) nanosheets were synthesized through a hydrothermal method,and simultaneously,CeO_(2) nanoparticles were grown on their surfaces,forming an S-scheme heterojunction modified with Ce^(3+)/Ce^(4+)ion bridges.Time-resolved photoluminescence(TRPL)and photoelectrochemical tests demonstrated the enhanced charge separation effect of this heterojunction.In situ X-ray photoelectron spectroscopy(In situ XPS)analysis and theoretical calcul

关 键 词：光催化CO_(2)转化 CeO_(2) Bi_(2)MoO_(6) S型异质结 电荷转移 

分 类 号：O643[理学—物理化学]