催化学报

催化学报

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通过掺杂优化CdS/ZnO S型异质结界面电子转移和表面氢吸附的理论计算研究

周亚太a, 袁成成a, 夏伟a, 王骏b, 朱潇锋b, 张勇c, 朱必成a,b,*, 余家国a,*   

  1. a中国地质大学(武汉)材料与化学学院, 太阳燃料实验室, 湖北武汉 430078;
    b西南科技大学材料与化学学院, 环境友好能源材料国家重点实验室, 四川绵阳 621010;
    c湖北理工学院新材料与绿色化工学院, 高分子材料化学助剂湖北省工程研究中心, 湖北黄石 435003
  • 收稿日期:2025-12-09 接受日期:2026-01-05
  • 通讯作者: *电子信箱: zhubicheng@cug.edu.cn (朱必成), yujiaguo93@cug.edu.cn (余家国).
  • 基金资助:
    国家自然科学基金(52173065, U24A2071, 52372294, 22361142704, 22238009); 环境友好能源材料国家重点实验室开放基金(24kfhg05); 湖北省自然科学基金黄石创新发展联合基金重点项目(2025AFD004).

Synergistic optimization of interfacial electron transfer and surface hydrogen adsorption in a CdS/ZnO S-scheme heterojunction by site-specific doping: A DFT study

Yatai Zhoua, Chengcheng Yuana, Wei Xiaa, Jun Wangb, Xiaofeng Zhub, Yong Zhangc, Bicheng Zhua,b,*, Jiaguo Yua,*   

  1. aLaboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430078, Hubei, China;
    bState Key Laboratory of Environment-Friendly Energy Materials, School of Materials and Chemistry, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China;
    cSchool of Advanced Materials and Green Chemical Engineering, Hubei Engineering Research Center for Chemical Additives of Polymer Materials, Hubei Polytechnic University, Huangshi 435003, Hubei, China
  • Received:2025-12-09 Accepted:2026-01-05
  • Contact: *E-mail: zhubicheng@cug.edu.cn (B. Zhu), yujiaguo93@cug.edu.cn (J. Yu).
  • Supported by:
    National Natural Science Foundation of China (52173065, U24A2071, 52372294, 22361142704, 22238009), the Open Project of State Key Laboratory of Environment-friendly Energy Materials (24kfhg05), and the Hubei Provincial Natural Science Foundation Innovation and Development Joint Fund Key Project of Huangshi (2025AFD004).

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摘要： 光催化分解水制氢为应对全球能源危机提供了一种极具前景的策略. 然而, 单一光催化剂的性能通常较低, 主要是由于光生电子与空穴的快速复合, 以及表面氧化还原反应缓慢的动力学. 将一种氧化型光催化剂(OP)和一种还原型光催化剂(RP)组合, 构建梯型(S型)异质结, 能够利用OP中还原能力弱的光生电子消耗掉RP中氧化能力弱的光生空穴, 使得RP导带具有强还原能力的光生电子得以保留, 进而高效地催化产氢反应, 因此成为了光催化制氢领域的研究热点. 尽管已取得重要进展, 目前已实现的产氢速率仍难以满足实际应用的需求. 因此, 需要对S型异质结进行进一步优化, 主要包括两个方面: 进一步提高异质结界面电荷转移与分离的效率, 以及加速表面产氢反应的动力学.
元素掺杂是调控半导体电子结构和增强光催化活性的另一种有效策略. 随着S型异质结研究的逐步深入, 一些实验研究发现, 在S型异质结中引入杂质原子可以进一步增强光催化产氢性能. 性能增强的原因通常被归结为掺杂后载流子的分离效率得到提高. 然而, 一些关键的科学问题没有得到解答, 包括杂质原子影响界面载流子转移的内在机制、杂质原子对表面产氢反应动力学的调控作用, 以及不同掺杂位点对于性能增强的不同作用. 本文构建了CdS/ZnO S型异质结, 将CdS中不同位置的Cd原子替换为过渡金属(TM = Cr, Mn, Fe, Co和Ni)原子, 得到了三种具有不同掺杂位点的TM掺杂CdS/ZnO复合物模型: 仅表面掺杂、仅界面掺杂, 以及表面和界面共掺杂. 对这些模型开展密度泛函理论(DFT)计算, 研究不同位点TM掺杂对CdS/ZnO S型异质结的几何结构、电子性质和表面氢吸附的影响. 结果表明, 所有掺杂构型均能同时增强界面电子转移和优化表面氢吸附自由能(ΔGH*). 其中, TM原子在界面的掺杂导致CdS的功函数减小, 由此增大了CdS和ZnO的费米能级差, 使得异质结形成时从CdS转移到ZnO的电子数增多, 增强了界面内建电场. TM原子在表面的掺杂导致表面S原子的p带中心降低, 由此削弱了H吸附在异质结表面时形成的S-H键, 使得ΔGH*的绝对值减小, 促进了表面H吸附-脱附平衡. 而且, 表面和界面共掺杂时表现出显著的协同效应, 它在增强界面电子转移和优化ΔGH*方面的作用比单一表面掺杂或单一界面掺杂的作用更强. 此外, 对于同一种掺杂构型, 随着TM原子序数的增加(从Cr至Ni), 界面电子转移的增强和表面氢吸附的弱化程度都逐渐降低, 这同样与掺杂后CdS的功函数和表面S原子的p带中心的变化有关.
综上, 本文通过DFT计算, 揭示了TM原子在不同位点掺杂影响CdS/ZnO S型异质结的界面电子转移和表面氢吸附的内在机制. 本工作突显了多位点掺杂策略在协同调控S型异质结电荷转移与表面反应方面的重要潜力, 为高效异质结光催化剂的精准设计提供了有价值的理论见解.

关键词: S型异质结, 过渡金属, 掺杂位点, 界面电子转移, 氢吸附, 密度泛函理论

Abstract: Fine-tuning the interfacial electronic interaction and surface reactivity of S-scheme heterojunctions is critical for advancing their photocatalytic performance. This study employs density functional theory calculations to systematically investigate the effects of transition metal (TM = Cr, Mn, Fe, Co, and Ni) doping at distinct sites of a CdS/ZnO S-scheme heterojunction: the surface (TMs), the interface (TMi), and co-doping at both sites (TMs+i). The results demonstrate that all doping configurations concurrently enhance both interfacial electron transfer and the hydrogen evolution reaction dynamics. The augmentation of electron transfer across the interface is primarily driven by TM doping at the interface, which reduces the work function of CdS and enlarges the Fermi level discrepancy with ZnO, leading to an enhancement trend of TMs+i > TMi > TMs. Conversely, the optimization of hydrogen adsorption free energy (ΔGH*) is chiefly governed by surface TM doping, which downshifts the p-band center of S atoms and weakens the S-H bond, resulting in an improvement trend of TMs+i > TMs > TMi. Remarkably, the co-doping configuration exhibits a pronounced synergistic effect, outperforming any single-site doping in optimizing both properties. Furthermore, a clear periodic trend is identified: the promotional effect of TM doping, from Cr to Ni, progressively diminishes for both charge separation and surface reaction, which is linked to the increasing work function and S p-band center. This work highlights the significant potential of a multi-site doping strategy for the synergistic engineering of charge transfer and surface reactions in S-scheme heterojunctions, offering valuable theoretical insights for the precise design of high-efficiency photocatalysts.

Key words: S-scheme heterojunctions, Transition metals, Doping sites, Interfacial electron transfer, Hydrogen adsorption, Density functional theory