Aerosol-assisted facile fabrication of bimetallic Cr2O3-Mn2O3 thin films for photoelectrochemical water splitting
Document Type
Article
Publication Date
5-1-2023
Abstract
In the present studies, we demonstrate a simple and efficient method to fabricate Cr2O3-Mn2O3 composite thin films of immaculate homogeneity for photoelectrochemical (PEC) study. The clear THF solution of chromium(II) acetate hydrate and manganese(II) acetate tetrahydrate precursors in a 1 : 1 mole ratio was used in the aerosol-assisted chemical vapor deposition (AACVD) over FTO-coated glass substrates at the temperatures of 400, 450, and 500 degrees C in ambient argon conditions. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) analyses verified the formation of uniformly dispersed crystalline Cr2O3 and Mn2O3 phases. Direct optical band gaps at 2.50, 2.39, and 2.10 eV were measured at 400, 450, and 500 degrees C, respectively, from UV-Vis spectrophotometry. X-ray photoelectron spectroscopy (XPS) was carried out to investigate the oxidation state of the constituent elements in the prepared sample. PEC studies revealed that the synergistic effect appeared between Cr2O3 and Mn2O3 phases to facilitate the photo-oxidation of water, leading to a photocurrent density of 1.25 mA cm(-2) at 1.23 V vs. RHE. The Cr2O3-Mn2O3 composite thin film at 500 degrees C having a more compact structure shows the highest photocurrent density among all samples (0.32 mA cm(-2) at 1.23 V vs. RHE for 400 and 450 degrees C). Kinetics of the photocatalysis were investigated by electrochemical impedance spectroscopy (EIS), and a decrease in charge transfer resistance (Rct) was observed with the rise in deposition temperature. Deposition at different temperatures resulted in the improvement of photocatalytic activity, and these findings may lead to advantageous modification in the fabrication of thin film photoelectrodes for PEC water splitting.
Keywords
Aerosol-assisted facile fabrication, Bimetallic Cr2O3-Mn2O3, Thin films, Photoelectrochemical water splitting
Divisions
mechanical,CHEMISTRY
Funders
NRPU research grant (20-12197/NRPU/RGM/RD/HEC/2020),Universiti Malaya Impact-Oriented Interdisciplinary Research Grant (IIRG006A-19IISS),Higher Education Commission of Pakistan
Publication Title
New Journal of Chemistry
Volume
47
Issue
17
Publisher
Royal Society of Chemistry
Publisher Location
THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND