物理化学学报 >> 2022, Vol. 38 >> Issue (7): 2108028.doi: 10.3866/PKU.WHXB202108028

所属专题： 异质结光催化材料

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一维/二维W18O49/多孔g-C3N4梯形异质结构建及其光催化析氢性能研究

黄悦1, 梅飞飞1, 张金锋1,*(), 代凯1,*(), Graham Dawson2   

  1. 1 淮北师范大学，污染物敏感材料与环境修复安徽省重点实验室，安徽 淮北 235000
    2 西交利物浦大学化学系，江苏 苏州 215123
  • 收稿日期:2021-08-19 录用日期:2021-09-04 发布日期:2021-09-09
  • 通讯作者: 张金锋,代凯 E-mail:jfzhang@chnu.edu.cn;daikai940@chnu.edu.cn
  • 作者简介:第一联系人：

    †These authors contributed equally to this work.

  • 基金资助:
    国家自然科学基金(51572103);国家自然科学基金(51973078);安徽省杰出青年基金(1808085J14);安徽省教育厅重大项目(KJ2020ZD005)

Construction of 1D/2D W18O49/Porous g-C3N4 S-Scheme Heterojunction with Enhanced Photocatalytic H2 Evolution

Yue Huang1, Feifei Mei1, Jinfeng Zhang1,*(), Kai Dai1,*(), Graham Dawson2   

  1. 1 Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Huaibei Normal University, Huaibei 235000, Anhui Province, China
    2 Department of Chemistry, Xi'an Jiaotong Liverpool University, Suzhou 215123, Jiangsu Province, China
  • Received:2021-08-19 Accepted:2021-09-04 Published:2021-09-09
  • Contact: Jinfeng Zhang,Kai Dai E-mail:jfzhang@chnu.edu.cn;daikai940@chnu.edu.cn
  • About author:Email: daikai940@chnu.edu.cn (K.D.)
    Email: jfzhang@chnu.edu.cn (J.Z.). Tel.: +86-561-3803256
  • Supported by:
    the National Natural Science Foundation of China(51572103);the National Natural Science Foundation of China(51973078);the Distinguished Young Scholar of Anhui Province, China(1808085J14);the Major projects of Education Department of Anhui Province, China(KJ2020ZD005)

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摘要：

提高光催化分解水制氢的效率是能量转换领域的关键挑战。本研究首先合成了二维多孔氮化碳(PCN)，然后在二维PCN上原位生长了一维W18O49 (WO)，形成了一种新型的梯形(S型)异质结。该异质结可以加快界面电荷的分离和转移，赋予WO/PCN体系更好的氧化还原能力。此外，具有多孔结构的PCN提供了更多的催化活性位点。与WO和PCN相比，20% WO/PCN复合材料具有更高的H2产率(1700 μmol·g-1·h-1)，是PCN (30 μmol·g-1·h-1)的56倍。本研究提供了一种新S型光催化剂用于光催化制氢领域。

关键词: S型, 光催化制氢, W18O49, 多孔氮化碳, 异质结

Abstract:

Photocatalytic hydrogen production is an effective strategy for addressing energy shortage and converting solar energy into chemical energy. Exploring effective strategies to improve photocatalytic H2 production is a key challenge in the field of energy conversion. There are numerous oxygen vacancies on the surface of non-stoichiometric W18O49 (WO), which result in suitable light absorption performance, but the hydrogen evolution effect is not ideal because the band potential does not reach the hydrogen evolution potential. A suitable heterojunction is constructed to optimize defects such as high carrier recombination rate and low photocatalytic performance in a semiconductor. Herein, 2D porous carbon nitride (PCN) is synthesized, followed by the in situ growth of 1D WO on the PCN to realize a step-scheme (S-scheme) heterojunction. When WO and PCN are composited, the difference between the Fermi levels of WO and PCN leads to electron migration, which balances the Fermi levels of WO and PCN. Electron transfer leads to the formation of an interfacial electric field and bends the energy bands of WO and PCN, thereby resulting in the recombination of unused electrons and holes while leaving used electrons and holes, which can accelerate the separation and charge transfer at the interface and endow the WO/PCN system with better redox capabilities. In addition, PCN with a porous structure provides more catalytic active sites. The photocatalytic performance of the sample can be investigated using the amount of hydrogen released. Compared to WO and PCN, 20%WO/PCN composite has a higher H2 production rate (1700 μmol·g-1·h-1), which is 56 times greater than that of PCN (30 μmol·g-1·h-1). This study shows the possibility of the application of S-scheme heterojunction in the field of photocatalytic H2 production.

Key words: S-scheme, Photocatalytic H2 production, W18O49, Porous carbon nitride, Heterojunction