化学学报 ›› 2026, Vol. 84 ›› Issue (7): 1140-1152.DOI: 10.6023/A26040135 上一篇    下一篇

研究论文

S/B/K共掺杂调控氮化碳电子结构用于高效光催化合成H2O2

冯丹宁a, 封波a, 万坤a, 谢颂海a, 裴燕a, 乔明华a,*(), 宗保宁b,*()   

  1. a 复旦大学化学系多孔材料与分离转化全国重点实验室 上海市分子催化和功能材料重点实验室 上海 200438
    b 中国石化石油化工科学研究院催化材料与反应工程国家重点实验室 催化材料与反应工程国家重点实验室 北京 100083
  • 投稿日期:2026-04-24 发布日期:2026-06-24
  • 基金资助:
    国家重点研发专项项目(2021YFA1501404); 国家自然科学基金(22272030); 上海市重点实验室专项经费(2024DZSYS02)

Electronic Structure Engineering of g-C3N4 via S/B/K Co-Doping for Efficient Photocatalytic H2O2 Synthesis

Danning Fenga, Bo Fenga, Kun Wana, Songhai Xiea, Yan Peia, Minghua Qiaoa,*(), Baoning Zongb,*()   

  1. a State Key Laboratory of Porous Materials for Separation and Conversion and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
    b State Key Laboratory of Catalytic Materials and Reaction Engineering, Research Institute of Petroleum Processing,SINOPEC, Beijing 100083, China
  • Received:2026-04-24 Published:2026-06-24
  • Contact: * E-mail: mhqiao@fudan.edu.cn; zongbn.ripp@sinopec.com; Tel.: 021-31244679
  • Supported by:
    National Key Research and Development Project of China(2021YFA1501404); National Natural Science Foundation of China(22272030); Science and Technology Commission of Shanghai Municipality(2024DZSYS02)

基于石墨相氮化碳(g-C3N4)光催化氧气(O2)还原合成过氧化氢(H2O2)具有重要的基础研究价值和实际应用价值. 针对g-C3N4电子结构对称性高、光生载流子复合严重、O2活化能力弱及光催化合成H2O2效率低的核心瓶颈, 本工作提出了一种多元素共掺杂协同缺陷工程调控电子结构的改性策略, 通过两步煅烧结合离子热处理, 成功制备了S/B/K三元共掺杂的g-C3N4催化剂(KBSCN). 该策略同步实现了富电子S、缺电子B和K在g-C3N4骨架内的均匀掺杂, 以及氰基(−C≡N)和氮空位(Nv)的原位引入. 系统开展了结构表征、光电性能测试与光催化性能评价, 并结合密度泛函理论(DFT)计算, 揭示了多元素掺杂对g-C3N4电子结构与反应动力学的协同调控机制. 研究结果表明, S/B/K三元共掺杂可有效打破g-C3N4的对称结构, 拓宽可见光响应范围. 光催化O2还原合成H2O2性能评价结果表明, 在可见光照射下, KBSCN催化剂上的H2O2生成速率高达8132 μmol•g−1•h−1, 为未改性g-C3N4(CN)生成速率的185倍. 机理研究表明, S/B/K三元共掺杂通过诱导最高占据分子轨道(HOMO)与最低未占据分子轨道(LUMO)的空间分离, 极大促进了光生载流子的分离与迁移. 此外, 结合自由基捕获实验、原位电子顺磁共振(EPR)、原位漫反射傅里叶变换红外(in situ DRIFT)表征与Bader电荷电子转移分析, S/B/K三元共掺杂可促进光催化O2还原反应(ORR)采取以超氧自由基(•O2)为中间体的间接两电子还原路径, 从动力学上显著提升2e-ORR的反应速率. 本工作通过对g-C3N4的电子结构与表面反应动力学的调控实现了可见光驱动下高效合成H2O2, 为低成本、高性能光催化合成H2O2催化剂的设计提供了新的思路.

关键词: 光催化, H2O2, g-C3N4, 多元素共掺杂, 协同效应

Efficient photocatalytic reduction of O2 to H2O2 over graphitic carbon nitride (g-C3N4) is of significant practical value. To overcome the intrinsic drawbacks of g-C3N4 including high electronic structure symmetry, severe photogenerated carrier recombination, weak O2 activation ability, and low photocatalytic H2O2 synthesis efficiency, herein a regulation strategy of electronic structure via multi-element co-doping coupled with defect engineering was proposed. A S/B/K ternary co-doped g-C3N4 catalyst (denoted as KBSCN) was fabricated by a facile two-step calcination followed by ionothermal treatment. This strategy enabled the simultaneous homogeneous incorporation of electron-rich S and electron-deficient B into the g-C3N4 framework, intercalation of K, as well as the introduction of cyano groups (−C≡N) and nitrogen vacancies (Nv). The structural and photoelectrochemical properties of KBSCN were systematically characterized, and its photocatalytic performance in photocatalytic reduction of O2 to H2O2 was evaluated. Combined with density functional theory (DFT) calculations, the synergistic regulation mechanism of multi-element doping on the electronic structure and reaction kinetics of KBSCN was elucidated. S/B/K ternary co-doping can effectively break the inherent symmetric structure and broaden the visible light response range of g-C3N4. In photocatalytic reduction of O2, under visible light irradiation, KBSCN exhibited a H2O2 production rate of 8132 μmol•g−1•h−1, which was 185 times that of pristine g-C3N4. Mechanistic studies indicate that S/B/K co-doping greatly promotes the separation and migration of photogenerated carriers by inducing the spatial separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Moreover, by combining radical scavenging experiments, in situ electron paramagnetic resonance (EPR), in situ diffuse reflectance infrared Fourier transform (in situ DRIFT) spectroscopy characterizations and Bader charge analysis for electron transfer, it is revealed that S/B/K co-doping drives the photocatalytic O2 reduction reaction (ORR) to proceed via an indirect two-electron reduction pathway with superoxide radicals (•O2) as the intermediate, thus significantly boosting the reaction kinetics of the 2e-ORR process. This work provides a new avenue for the design of g-C3N4-based catalysts for efficient visible light-driven H2O2 synthesis via synergistic regulation of electronic structure and surface reaction kinetics.

Key words: photocatalysis, H2O2, g-C3N4, multi-element co-doping, synergistic effect