Fabrication of fe-doped molybdenum multisulfide MoS2/Mo2S3 thin film via aerosol-assisted chemical vapor deposition (AACVD) for photoelectrochemical (PEC) water splitting

• Main Authors: Lau, Kelvin C., Ooi, Mei Lee, Ooi, Zhong Xian, Wong, Richard C. S., Choong, Zheng Lin, Mazhar, Muhammad, Goh, Boon Tong
• Format: Article
• Published: Springer 2022
• Subjects: QD Chemistry
• Online Access: http://eprints.um.edu.my/33473/

Mixed iron molybdenum multisulfide composite thin films had been deposited at 550 degrees C for 20 min from dual source precursors of Cp2Fe and CpMo(SMe)(2)](2) (2) via AACVD method. The 10, 20, 40, and 80 mol% of added Cp2Fe as the dopant produced thin films with different morphologies, particle sizes, thicknesses, and oxidation states for the iron atom. The x-ray diffraction (XRD) analyses showed the presence of MoS2/Mo2S3/Fe(MoS2)(2) while the existence of standing flakes array was observed in the 3D atomic force microscopy (AFM) analyses. The photoelectrochemical study of these thin films revealed that at overpotential of 1.23 V vs RHE under solar simulator of 100 mW/cm(2), the 40 mol% Fe-doped thin film comprising both Fe2+/Fe3+ yielded the highest photocurrent density of 1.241 mA/cm(2), while the 80 mol% Fe-doped thin film containing only Fe3+ showed lower photocurrent density of 0.761 mA/cm(2) but with the highest photosensitivity of 1.396 with the longest lifetime for the electron hole recombination. However, the electrochemical impedance spectroscopy (EIS) analyses showed that the 80 mol% Fe-doped thin film with the thickest coating had the lowest charge mobility. This study had shown that the amount of doped iron in molybdenum multisulfide and its oxidation state also influenced its photoelectrochemical properties as well. The mechanism of electron transfer involved in this study has been illustrated by a Z-scheme.