催化学报

催化学报 ›› 2025, Vol. 79: 174-185.DOI: 10.1016/S1872-2067(25)64849-2

• 论文 • 上一篇    下一篇

Na2CO3辅助合成钠掺杂结晶/非晶g-C3N4 S型同质结光催化剂用于增强H2O2合成

谭丽红a, 吴新鹤a,*(), 许家超a, 王国宏a,*()   

  1. a湖北师范大学化学化工学院, 污染物分析与再利用技术湖北省重点实验室, 湖北黄石435002, 中国
    b中国地质大学(武汉)材料科学与化学学院, 太阳能燃料实验室, 湖北武汉430074, 中国
    c法尤姆大学理学院, 法尤姆, 埃及
  • 收稿日期:2025-08-05 接受日期:2025-08-25 出版日期:2025-12-05 发布日期:2025-10-27
  • 通讯作者: 吴新鹤,王国宏
  • 基金资助:
    国家自然科学基金(22302061);国家自然科学基金(22578106);国家自然科学基金(W2433135);国家自然科学基金(22402126)

Na2CO3-assisted synthesis of Na-doped crystalline/amorphous g-C3N4 S-scheme homojunction photocatalyst for enhanced H2O2 production

Lihong Tana, Xinhe Wua,*(), Jiachao Xua, Mahmoud Sayedb,c,*(), Guohong Wanga,*()   

  1. aHubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, Hubei, China
    bLaboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, Hubei, China
    cChemistry Department, Faculty of Science, Fayoum University, Fayoum 63514, Egypt
  • Received:2025-08-05 Accepted:2025-08-25 Online:2025-12-05 Published:2025-10-27
  • Contact: Xinhe Wu, Mahmoud Sayed, Guohong Wang
  • Supported by:
    National Natural Science Foundation of China(22302061);National Natural Science Foundation of China(22578106);National Natural Science Foundation of China(W2433135);National Natural Science Foundation of China(22402126)

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摘要：

近年来, 光催化技术因其反应条件温和、操作简便、环境友好而成为一种理想的可持续性技术. 在众多提升光催化性能的策略中, 结晶/无定形g-C3N4同质结的构建是一种具有广泛应用前景的策略, 可用于制备界面匹配性更优、载流子传输阻力更低的同质结光催化剂, 从而显著提升光催化性能. 然而, 传统的促进g-C3N4结晶的方法通常涉及复杂的多步处理操作及有毒化学品的使用, 因而限制了其实际应用的可行性. 例如, 现有方法大多采用有毒化学品—LiCl作为缩合反应溶剂. 此外, 此前的g-C3N4结晶体系大多需要采用双盐, 且所使用的两种盐的共熔点必须低于550 oC, 才能作为调控g-C3N4聚合过程的溶剂, 这极大限制了共熔盐的选择及该方法的发展.
因此, 本文提出了一种创新的Na2CO3诱导结晶度调控策略, 成功实现了钠掺杂结晶/无定形g-C3N4 S型同质结光催化剂的一步构筑. 该方法以三聚氰胺与三聚氰酸分子的预组装为基础, 通过调控二者的比例实现对分子组装程度及表面组成(如是否暴露氨基基团-NH2)的精确控制. 在煅烧前引入Na2CO3, 利用体系中过量三聚氰胺分子所提供的充足-NH2基团, 通过氢键作用与Na2CO3有效结合, 从而在后续的一步煅烧过程中同步实现结晶度调控与钠离子掺杂, 最终获得钠掺杂结晶/无定形g-C3N4 S型同质结光催化剂. 所制备的光催化剂在H2O2合成中表现出优异的光催化性能, 最优的H2O2生成速率达到444.6 μmol·L‒1·h‒1, 相较于块体g-C3N4提升6.1倍. X射线衍射、X射线光电子能谱、傅里叶变换红外光谱和电化学测试等实验表征和密度泛函理论计算结果表明, S型同质结的构建有效促进了光生载流子的空间分离与高效传输; 与此同时, 钠离子掺杂优化了O2吸附与*OOH中间体转化等过程, 从而显著增强了界面H2O2生成动力学, 二者协同作用显著提升了钠掺杂结晶/无定形g-C3N4 S型同质结光催化剂的H2O2光催化生成活性.
综上, 本研究不仅提供了一种高效、简便、环保的一步煅烧法构建g-C3N4基S型同质结的新策略, 还通过结晶/无定形复合结构与金属掺杂的协同作用, 为设计高活性光催化剂提供了新思路, 在太阳能燃料合成和光催化等领域具有重要的应用潜力.

关键词: 光催化, S型同质结, 结晶/无定形g-C3N4, 结晶度调控, H2O2合成

Abstract:

The construction of crystalline/amorphous g-C3N4 homojunctions presents a versatile strategy to obtain all-organic homojunction photocatalysts with better interface matching and lower interface charge carrier movement resistance for optimized photocatalytic activity. However, the process entails a complex multi-step workup, which compromises its feasibility. To overcome this challenge, this work provided an innovative Na2CO3-induced crystallinity modulation strategy to construct a Na-doped crystalline/amorphous g-C3N4 S-scheme homojunction photocatalyst in a single step. The approach involves the initial pre-assembling of melamine and cyanuric acid molecules, and subsequent introduction of Na2CO3 before the calcination. Na2CO3 plays key roles to induce in-situ crystallinity modulation during the calcination and as a source for Na-doping. The prepared g-C3N4 S-scheme homojunction photocatalyst demonstrated a prominent H2O2-production rate of 444.6 μmol·L-1·h-1, which is 6.1-fold higher than that of bulk g-C3N4. The enhanced activity was attributed to the synergistic effect of charge carrier separation induced by the S-scheme homojunction system, and the optimized interfacial H2O2 generation kinetics. The latter was fostered by the Na-doping. This study provides an innovative approach for the one-step construction of g-C3N4 S-scheme homojunction and its integration in photocatalytic applications.

Key words: Photocatalysis, S-scheme homojunction, Crystalline/amorphous g-C3N4, Crystallinity modulation, H2O2 production