Mondal Sneha, Dilly Rajan Karthik, Patra Lokanath, Rathinam Maheswaran, Ganesh Vattikondala
Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, 603203, India.
G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Small. 2025 Mar;21(11):e2411828. doi: 10.1002/smll.202411828. Epub 2025 Feb 3.
This study explores the role of S vacancies in MoS in enhancing its piezocatalytic efficiency. Sulfur vacancies in the crystal lattice introduce localized changes in the electronic structure and charge distribution, improving the material's piezoelectric response. Characterization of the catalysts involved techniques like field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements, including impedance spectroscopy (EIS) and Mott-Schottky (M-S) analysis, are performed to assess the piezocatalytic performance. The study also employed density functional theory (DFT) calculations to investigate the electronic structure and hydrogen adsorption properties of MoS with S vacancies. The results demonstrated that S-deficient MoS significantly enhanced piezocatalytic H evolution. The piezocatalytic H production rates of MoS with different vacancy concentrations are measured under ultrasonic vibration. The sample with an optimal vacancy concentration (MS-1) exhibited the highest H production rate of 1423.29 µmol g h, compared to 439.06 µmol g h for pristine MoS (MS-0). The improved performance is attributed to the increased piezoelectric polarization and efficient charge separation facilitated by S vacancies.
本研究探讨了二硫化钼中硫空位在提高其压电催化效率方面的作用。晶格中的硫空位会引起电子结构和电荷分布的局部变化，从而改善材料的压电响应。对催化剂的表征涉及场发射扫描电子显微镜（FESEM）、X射线衍射（XRD）、透射电子显微镜（TEM）和X射线光电子能谱（XPS）等技术。进行了包括阻抗谱（EIS）和莫特-肖特基（M-S）分析在内的电化学测量，以评估压电催化性能。该研究还采用密度泛函理论（DFT）计算来研究含硫空位的二硫化钼的电子结构和氢吸附性能。结果表明，缺硫的二硫化钼显著增强了压电催化析氢性能。在超声振动下测量了不同空位浓度的二硫化钼的压电催化产氢速率。具有最佳空位浓度的样品（MS-1）的产氢速率最高，为1423.29µmol g h，而原始二硫化钼（MS-0）的产氢速率为439.06µmol g h。性能的改善归因于硫空位促进的压电极化增加和有效的电荷分离。
