催化学报

催化学报 ›› 2025, Vol. 76: 108-119.DOI: 10.1016/S1872-2067(25)64747-4

• 论文 • 上一篇    下一篇

Co诱导不对称电荷分布弱化S-Had键增强NiCoS助剂的光催化制氢性能

钟威, 孟爱云, 蔡旭东, 甘义遥, 王敬涛, 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:2025-03-28 接受日期:2025-05-06 出版日期:2025-09-18 发布日期:2025-09-10
  • 通讯作者: 苏耀荣
  • 作者简介:第一联系人：

    1共同第一作者.

  • 基金资助:
    国家自然科学基金(22178224);国家自然科学基金(22272110);国家自然科学基金(22402126);广东省基础与应用基础研究基金(2023A1515110535);深圳市科技计划(RCBS20231211090522041);污染物分析与资源化技术湖北省重点实验室(湖北师范大学)(PA240201);深圳市超金刚石与功能晶体应用技术重点实验室(ZDSYS20230626091303007)

Enhancing photocatalytic H2 evolution by weakening S-Had bonds via Co-induced asymmetric electron distribution in NiCoS cocatalysts

Wei Zhong, Aiyun Meng, Xudong Cai, Yiyao Gan, Jingtao Wang, Yaorong Su*()   

  1. College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, Guangdong, China
  • Received:2025-03-28 Accepted:2025-05-06 Online:2025-09-18 Published:2025-09-10
  • Contact: Yaorong Su
  • About author:First author contact:

    1Contributed equally to this work.

  • Supported by:
    National Natural Science Foundation of China(22178224);National Natural Science Foundation of China(22272110);National Natural Science Foundation of China(22402126);Guangdong Basic and Applied Basic Research Foundation(2023A1515110535);Shenzhen Science and Technology Program(RCBS20231211090522041);Hubei Key Laboratory of Pollutant Analysis & Reuse Technology (Hubei Normal University)(PA240201);Shenzhen Key Laboratory of Applied Technologies of Super-Diamond and Functional Crystals(ZDSYS20230626091303007)

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摘要：

太阳能驱动的半导体光催化制氢技术可直接将太阳能转化为氢能, 被认为是极具发展潜力的氢能制取途径之一. 然而, 传统半导体材料存在光生电子-空穴复合率高及界面析氢反应动力学缓慢的问题, 导致光催化制氢效率低. 在半导体材料表面修饰助催化剂可以有效分离光生电子并提高界面析氢反应速率, 是提高光催化制氢效率的有效方法.

硫化镍(NiS)助催化剂具有导电性高、化学性质稳定、原料丰富等优点, 在光催化制氢领域备受关注. 然而, 传统NiS助剂材料在界面析氢过程中容易产生强S-Had键, 导致界面析氢反应速率慢, 光催化制氢活性较低. 因此, 进一步调控NiS的电子结构以弱化S-Had键对提升NiS助剂的制氢性能具有重要意义.

本文提出将Co原子引入NiS的结构中, 打破其中Ni和S原子的对称电荷分布, 从而优化活性S原子的电子结构, 进而提高其界面析氢反应速率. 本研究通过一步光诱导沉积方法成功在TiO2材料表面修饰了NiCoS助催化剂, 可控制备了NiCoS/TiO2光催化材料. 通过高倍透射电镜和X射线衍射等方法证实了NiCoS助催化剂的粒径约10 nm, 且具有均相结构. 光催化制氢结果表明, 当Ni与Co原子比为1:2时, NiCoS/TiO2(1:2)材料的光催化制氢速率最高, 达2702.96 μmol g-1 h-1, 是NiS/TiO2样品的2.1倍. X射线光电子能谱(XPS)和密度泛函理论计算结果表明, Co原子的引入能够诱导NiCoS结构中产生不对称的电荷分布, 使得S原子的电子密度增加, 产生大量的富电子S(2+δ)-位点. 此类富电子S(2+δ)-位点与Had结合后, 反键轨道填充度增加, 从而有效地弱化了S(2+δ)--Had键. 此外, 原位XPS和飞秒瞬态吸收光谱表明, NiCoS助催化剂可以促进TiO2表面光生电子的快速转移, 从而抑制光生载流子复合. 基于实验表征和理论计算结果, NiCoS/TiO2光催化材料的制氢性能提升主要归因于: (1) TiO2受光激发产生的光生电子可快速被NiCoS助剂捕获, 提高了光生电子的利用率; (2) NiCoS助剂能够提供大量的活性富电子S(2+δ)-位点, 提高了H+还原制H2的界面反应速率.

综上, 本研究提出了Co诱导不对称电荷分布策略优化活性S原子的电子结构, 增加活性S原子的电子密度, 显著提升了光催化制氢效率. 该策略为高效光催化制氢助剂的设计提供了新思路.

关键词: 制氢, 光催化, 不对称电荷分布, S-Had键, 反键轨道填充

Abstract:

The intrinsic symmetrical electron distribution in crystalline metal sulfides usually causes an improper electronic configuration between catalytic S atoms and H intermediates (Had) to form strong S-Had bonds, resulting in a low photocatalytic H2 evolution activity. Herein, a cobalt-induced asymmetric electronic distribution is justified as an effective strategy to optimize the electronic configuration of catalytic S sites in NiCoS cocatalysts for highly active photocatalytic H2 evolution. To this end, Co atoms are uniformly incorporated in NiS nanoparticles to fabricate homogeneous NiCoS cocatalyst on TiO2 surface by a facile photosynthesis strategy. It is revealed that the incorporated Co atoms break the electron distribution symmetry in NiS, thus essentially increasing the electron density of S atoms to form active electron-enriched S(2+δ)- sites. The electron-enriched S(2+δ)- sites could interact with Had via an increased antibonding orbital occupancy, which weakens S-Had bonds for efficient Had adsorption and desorption, endowing the NiCoS cocatalysts with a highly active H2 evolution process. Consequently, the optimized NiCoS/TiO2(1:2) photocatalyst displays the highest H2 production performance, outperforming the NiS/TiO2 and CoS/TiO2 samples by factors of 2.1 and 2.5, respectively. This work provides novel insights on breaking electron distribution symmetry to optimize catalytic efficiency of active sites.

Key words: H2 evolution, Photocatalysis, Asymmetric electron distribution, S-Had bonds, Antibonding occupancy