物理化学学报 >> 2024, Vol. 40 >> Issue (11): 2406005.doi: 10.3866/PKU.WHXB202406005

所属专题: 太阳燃料制备

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K原子掺杂高度面间结晶的g-C3N4光催化剂及其高效H2O2光合成

钟威†, 郑丹†, 欧远新, 孟爱云*(), 苏耀荣*()   

  1. 深圳技术大学新材料与新能源学院, 广东 深圳 518118
  • 收稿日期:2024-06-05 修回日期:2024-07-16 录用日期:2024-07-17 发布日期:2024-10-14
  • 通讯作者: Email: mengaiyun@sztu.edu.cn (孟爱云)suyaorong@sztu.edu.cn; Tel: +86-755-2325-6080 (苏耀荣)
  • 作者简介:

    †These authors contributed equally to this work.

  • 基金资助:
    国家自然科学基金项目(22178224); 国家自然科学基金项目(22272110); 广东省基础与应用基础研究基金(2023A1515110535); 广东省基础与应用基础研究基金(2020A1515110873); 深圳市科技计划资助(RCBS20231211090522041); 深圳技术大学基础科研业务费(20211063010047); 深圳市超金刚石与功能晶体应用技术重点实验室(ZDSYS20230626091303007); 深圳市高校稳定支持项目(20231127203830001)

Simultaneously Improving Inter-Plane Crystallization and Incorporating K Atoms in g-C3N4 Photocatalyst for Highly-Efficient H2O2 Photosynthesis

Wei Zhong, Dan Zheng, Yuanxin Ou, Aiyun Meng*(), Yaorong Su*()   

  1. College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, Guangdong Province, China
  • Received:2024-06-05 Revised:2024-07-16 Accepted:2024-07-17 Published:2024-10-14
  • Contact: Email: mengaiyun@sztu.edu.cn (Aiyun Meng)suyaorong@sztu.edu.cn; Tel: +86-755-2325-6080 (Yaorong Su)
  • Supported by:
    the National Natural Science Foundation of China(22178224); the National Natural Science Foundation of China(22272110); Guangdong Basic and Applied Basic Research Foundation(2023A1515110535); Guangdong Basic and Applied Basic Research Foundation(2020A1515110873); Shenzhen Science and Technology Program(RCBS20231211090522041); the Fundamental Research Funds for Shenzhen Technology University(20211063010047); Shenzhen Key Laboratory of Applied Technologies of Super-Diamond and Functional Crystals(ZDSYS20230626091303007); Shenzhen Science and Technology Program(20231127203830001)

摘要:

石墨相氮化碳(g-C3N4)在光催化制备过氧化氢(H2O2)领域有巨大潜力。然而,低的两电子氧还原活性严重限制了g-C3N4的光催化产H2O2效率。在这项研究中,我们通过两步煅烧法在KI晶体表面重新晶化传统g-C3N4材料,合成了钾掺杂的高晶化g-C3N4光催化剂(CN-K)。所制备的CN-K光催化材料具有更高的面间结晶度、更窄的禁带宽度和更小的颗粒尺寸(大约20到50纳米)。更重要的是,掺入的钾原子作为优异的催化位点可以增强O2吸附和稳定*OOH中间体,从而提高钾掺杂高晶化g-C3N4光催化剂的两电子氧还原活性。其中CN-K(1:6)样品具有显著增强的光催化产H2O2速率(7.8 mmol·L-1·h-1),且在420 nm下的表观量子效率为5.17%,光催化活性是传统块状g-C3N4样品的220倍。这项研究不仅揭示了杂原子提高g-C3N4光催化剂两电子氧还原活性的机理,而且为设计高效g-C3N4基光催化剂提供了新的见解。

关键词: 光催化产H2O2, 氮化碳, 钾掺杂, 高选择性两电子氧还原

Abstract:

Graphitic carbon nitride (g-C3N4) has gained growing attention in hydrogen peroxide (H2O2) photosynthesis, but the low activity of two-electron oxygen reduction reaction (2e--ORR) still restricts its photocatalytic H2O2-generation performance. Herein, traditional g-C3N4 photocatalysts are recrystallized on KI crystal surfaces by a secondary calcination route to synthesize K incorporated highly-crystalline g-C3N4 photocatalysts. The synthesized CN-K photocatalyst exhibits improved inter-plane crystallization, narrowed bandgap structure, and smaller particle size from 20 to 50 nm. Moreover, the incorporated K atoms, as excellent catalytic sites, can enhance O2 adsorption and stabilize the *OOH intermediates, thus improving the 2e--ORR activity of the K incorporated high-crystallization g-C3N4 photocatalysts. Consequently, the optimized CN-K(1:6) photocatalyst exhibits a remarkably improved H2O2-generation rate of 7.8 mmol·L-1·h-1 with an AQE value of 5.17% at 420 nm, outperforming the traditional g-C3N4 sample by a factor of 220. This work uncovers the roles of heteroatoms in promoting the 2e--ORR selectivity of the g-C3N4 photocatalyst, and offers novel insights to construct highly-active g-C3N4-based materials for H2O2 photosynthesis.

Key words: Photocatalytic H2O2 evolution, Carbon nitride, K incorporation, Highly-selective 2e--ORR