第一作者：湖南大学 Kaihua Yang
通讯作者：湖南大学 张长、马驰
DOI：https://doi.org/10.1002/adma.202409832
在能量格局重塑的背景下，设计和合成用于析氢反应（HER）的高性能、超高原子利用率的无贵金属光催化剂仍然是一个挑战。在流线型的合成过程中，通过在模拟阳光下照射前驱缺陷态CdS/Co悬浮液（Co-DCdS- ss）体系，将原位单原子锚定与HER并行进行，与Co-DCdS- ss （18.09 mmol g−1 h−1）相比，原位合成的单原子Co光催化剂（Co5:DCdS）的催化性能进一步提高（60.10 mmol g−1h−1）。在500 nm处达到57.6%的表观量子产率，在AM 1.5G处达到6.26%的太阳能化学能量转换效率（SCC）。深入表征实验和密度泛函理论（DFT）计算证明，Co单原子的锚定加深了镉空位（VCd）附近双配位S原子的不对称电荷分布。构建了电子离域VCd与催化剂表面Co单原子的协同作用，其双功能位点负责促进水的吸附解离和析氢。该研究促进了对表面缺陷与金属单原子协同作用的潜在机制的理解，为光催化领域先进材料的开发开辟了新的视野。
Figure 1. a-c) HER performance of Co-PCdS-Ss and Co-DCdS-Ss in different sacrificial agent system, in different pH value and in different doses of Co. d-e) HER performance driven by simulated sunlight/visible light over Cox:DCdS and M:DCdS. f) Wavelength dependence of the AQY for Co5:DCdS. g) HER performance of Co5:DCdS in this work compared with representative reported photocatalysts.
Figure 2. High-resolution XPS spectra of PCdS, DCdS, and Co5:DCdS: a) Cd 3d orbital, b) S 2p orbital. c) Co 2p orbital spectrum of Co5:DCdS. d) HAADF-STEM image of Co5:DCdS corresponding to the EDS mapping. e-g) Corresponding elemental mapping. f) HAADF-STEM image demonstrating the atomic structure of Co5:DCdS. i) The Fourier Transform of (h). j) HAADF-STEM image demonstrating the surface defect of Co5:DCdS. k) Smaller scale HAADF-STEM of the region indicated in (j).
Figure 3. XAFS structural characterization of Co5:DCdS. a) Normalized Co K-edge XANES spectra and reference samples (Co foil, CoO, and CoS). b) The corresponding k3-weighted Fourier transform EXAFS spectra. c) EXAFS fitting curve of Co5:DCdS at R space. d–g) WT-EXAFS spectra of Co foil, CoO, CoS, and Co5:DCdS. h) Schematic diagram of the formation process and possible photochemical parallel reduction reactions resulting in H2 production and synthesis of Co single-atom decorated DCdS semiconductor.
Figure 4. a) UV-Vis absorbance spectra of PCdS, DCdS, and Co5:DCdS. b) PL spectra of PCdS, DCdS, and Co5:DCdS. c) TRPL spectra of PCdS, DCdS and Co5:DCdS. d-f) TRPL fitting curve of PCdS, DCdS, and Co5:DCdS. g) Transient photocurrent response curves. h) EIS Nyquist plots of the PCdS, DCdS, and Co5:DCdS. i) Schematic illustration of the mechanisms of electron transfer.
Figure 5. a–c) Structural models (top view) of PCdS, DCdS, and Co5:DCdS. d-f) Charge density distribution of diagrams of PCdS, DCdS, and Co5:DCdS. g) Adsorption energy and O-H bond length of H2Omolecules on PCdS, DCdS, and Co5:DCdS. h) Reaction energy diagram of H2O dissociation on PCdS, DCdS, and Co5:DCdS. i) The calculated ΔGH* values of PCdS, DCdS and Co5:DCdS.
Figure 6. a) Schematic of band gap and energy level bands. b) The generation rate of BD and H2 in photocatalytic BA oxidation reaction, c–d) The CO and CH4 generation rate in CO2 photoreduction.
In-Situ Anchoring of Co Single-Atom Synergistically with Cd Vacancy of Cadmium Sulfide for Boosting Asymmetric Charge Distribution and Photocatalytic Hydrogen Evolution
https://doi.org/10.1002/adma.202409832
