催化学报

催化学报 ›› 2022, Vol. 43 ›› Issue (9): 2321-2331.DOI: 10.1016/S1872-2067(21)63927-X

• 可再生燃料的光催化和光电催化合成专栏 • 上一篇    下一篇

高匹配的BiVO4/WO3纳米碗异质结光阳极用于高效光电化学分解水

张纹a, 田梦a, 焦海淼b, 蒋海英a,*(), 唐军旺b,#()   

  1. a西北大学化学与材料科学学院, 能源与催化中心, 合成与天然功能分子教育部重点实验室, 陕西西安710127
    b伦敦大学学院化学工程系, 英国
  • 收稿日期:2021-07-03 接受日期:2021-08-12 出版日期:2022-09-18 发布日期:2022-07-20
  • 通讯作者: 蒋海英,唐军旺
  • 基金资助:
    国家自然科学基金(21703170);陕西省重点研发计划(2020GY-244);西北大学青年学术人才计划和陕西省高等教育精品学科建设计划

Conformal BiVO4/WO3 nanobowl array photoanode for efficient photoelectrochemical water splitting

Wen Zhanga, Meng Tiana, Haimiao Jiaob, Hai-Ying Jianga,*(), Junwang Tangb,#()   

  1. aKey Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, The Energy and Catalysis Hub, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, Shaanxi, China
    bDepartment of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K.
  • Received:2021-07-03 Accepted:2021-08-12 Online:2022-09-18 Published:2022-07-20
  • Contact: Hai-Ying Jiang, Junwang Tang
  • About author:Prof. Junwang Tang (University College London, UK) is a member of Academia Europaea, a Royal Society Leverhulme Trust Senior Research Fellow, Fellow of the European Academy of Sciences, Fellow of the Royal Society of Chemistry and Professor of Materials Chemistry and Engineering in the Department of Chemical Engineering at University College London. Prof Tang received his BSc in Chemistry from the Northeastern University (1995), MSc in Materials from the Institute of Metal Research (1998), and PhD in Physical Chemistry from Dalian Institute of Chemical Physics, Chinese Academy of Sciences (2001), respectively. Then he undertook his JSPS fellowship in the National Institute for Materials Science, Japan (2002‒2005) and a senior researcher in Chemistry at Imperial College London (2005‒2009). Prof. Tang joined Materials Chemistry and Engineering, Department of Chemical Engineering, University College London, UK in 2009 as a Lecturer and was later promoted to Senior Lecturer (2011), Reader (2014), and Full Professor (2017). His research interests encompass photocatalytic small molecule activation (eg. H2O, CO2, N2, C6H6 and CH4) and microwave catalysis (e.g. catalytic plastic recycling), together with the investigation of the underlying charge dynamics and kinetics by state-of-the-art spectroscopies. In parallel, he also explores the design of the chemical reactors for the above-mentioned processes, resulting in > 200 papers published in Nature Catalysis, Nature Energy, Nature Reviews Materials, Chemical Reviews, Chem. Soc. Rev. Materials Today, Nature Commu., JACS, and Angew Chemie. He has also received many awards, the latest of which is the 2021 IChemE Andrew Medal due to his contribution to heterogeneous catalysis, the RSC Corday-Morgan Prize 2021 due to innovative photocatalysts discovered and 2021 IChemE Innovative Product Award due to the commercialisation of microwave-powered materials production process. Porf. Tang has been invited as an associate editor of Chinese Journal of Catalysis since 2014.
  • Supported by:
    National Natural Science Foundation of China(21703170);Key Research and Development Program of Shaanxi(2020GY-244);Young Academic Talents Program of Northwest University, Top-rated Discipline Construction Scheme of Shaanxi Higher education

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摘要：

光电化学(PEC)分解水制氢, 已成为将太阳能转化为绿色可持续氢能极具潜力的途径之一. 目前, 单斜相钒酸铋(BiVO4)因其合适的带隙及能带位置、无毒且含量丰富等优点, 被认为是理想的光阳极材料. 然而, BiVO4较低的载流子迁移率(4 × 10-2 cm2 V-1 s-1)和较短的空穴扩散长度(< 100 nm), 导致BiVO4光阳极电子-空穴复合较严重, 极大地限制了其性能. 为克服上述缺陷, 除减小BiVO4纳米颗粒的粒径以匹配其较短的空穴扩散长度, 使空穴能有效转移到其表面参与水氧化反应; 或在其表面沉积一层薄的氧气释放反应助催化剂(OEC)层以增强水氧化反应动力学以外, 还应关注如何进一步有效提升BiVO4电荷分离效率. 因此, 在BiVO4和氟掺杂的氧化锡(FTO)电极界面之间插入另一种半导体材料构筑异质结以促进BiVO4电荷分离, 进一步提升BiVO4电荷分离效率.

本文采用成本低廉、可控性高的单层胶体晶体(MCC)方法首先合成了单层WO3纳米碗(WO3NB)阵列, 再通过分步沉积法在单层WO3NB表面原位生长BiOI, 确保BiOI在WO3NB表面的完全覆盖, 最后通过热处理将BiOI转化为BiVO4纳米颗粒成功构建高匹配的BiVO4/WO3NB异质结. 在这种新颖的结构设计中, 小尺寸的BiVO4纳米颗粒(~90 nm)均匀地沉积在WO3纳米碗(内径约为920 nm)表面. 高度有序的WO3NB阵列担载了BiVO4的小尺寸和纳米结构, 最小化了WO3颗粒间的晶界缺陷, 并增加了与BiVO4纳米粒子的接触面积. 结合X射线粉末衍射、X射线光电子能谱、高分辨透射电子显微镜和能带分析发现, BiVO4与WO3NB匹配的能带位置和高度匹配的BiVO4/WO3NB界面可显著增强BiVO4与WO3NB之间的电荷传输; 此外, 光致发光光谱和电化学阻抗测试结果表明, 由于制备的BiVO4纳米颗粒尺寸小于其空穴扩散长度(~100 nm), 可确保空穴更有效的传递到NiOOH/FeOOH层中并参与表面水氧化反应; 在OEC/BiVO4和BiVO4/WO3NB两种结的协同作用下制备的NiOOH/FeOOH/BiVO4/WO3NB光阳极在中性电解质溶液Na2SO4溶液中, 1.23 V vs. RHE偏压下的光电流密度为3.02 mA cm-2, 法拉第效率达95%. 本文研究结果为设计与构筑高匹配多重“结”BiVO4光阳极提供了有效策略.

关键词: 光电化学分解水, WO3纳米碗, BiVO4, 电荷分离, NiOOH/FeOOH

Abstract:

As one of the most promising photoanode candidates for photoelectrochemical (PEC) water splitting, the photocurrent density of BiVO4 still needs to be further improved in order to meet the practical application. In this work, a highly-matched BiVO4/WO3 nanobowl (NB) photoanode was constructed to enhance charge separation at the interface of the junction. Upon further modification of the BiVO4/WO3NB surface by NiOOH/FeOOH as an oxygen evolution cocatalyst (OEC) layer, a high photocurrent density of 3.05 mA cm-2 at 1.23 V vs. RHE has been achieved, which is about 5-fold higher than pristine BiVO4 in neutral medium under AM 1.5 G illumination. 5 times higher IPCE at 450 nm is also achieved compared with the BiVO4 photoanode, leading to about 95% faradaic efficiency for both H2 and O2 gas production. Systematic studies attribute the significantly enhanced PEC performance to the smaller BiVO4 particle size (< 90 nm) than its hole diffusion length (~100 nm), the improved charge separation of BiVO4 by the single layer WO3 nanobowl array and the function of OEC layers. Such WO3NB possesses much smaller interface resistance with the substrate FTO glass and larger contact area with BiVO4 nanoparticles. This approach provides new insights to design and fabricate BiVO4-based heterojunction photoanode for higher PEC water splitting performance.

Key words: PEC water splitting, WO3 nanobowl, BiVO4, Charge separation, NiOOH/FeOOH