Simultaneous Enhancement of Charge Separation and Hole Transportation in a W:α-Fe2O3/MoS2 Photoanode: A Collaborative Approach of MoS2 as a Heterojunction and W as a Metal Dopant

Zohreh Masoumi; Meysam Tayebi; Morteza Kolaei; Ahmad Tayyebi; Hongsun Ryu; Joon I Jang; Byeong-Kyu Lee

doi:10.1021/acsami.1c08139

Simultaneous Enhancement of Charge Separation and Hole Transportation in a W:α-Fe₂O₃/MoS₂ Photoanode: A Collaborative Approach of MoS₂ as a Heterojunction and W as a Metal Dopant

ACS Appl Mater Interfaces. 2021 Aug 25;13(33):39215-39229. doi: 10.1021/acsami.1c08139. Epub 2021 Aug 10.

Authors

Zohreh Masoumi¹, Meysam Tayebi¹, Morteza Kolaei¹, Ahmad Tayyebi², Hongsun Ryu³, Joon I Jang³, Byeong-Kyu Lee¹

Affiliations

¹ Department of Civil and Environment Engineering, University of Ulsan, Daehakro 93, Namgu, Ulsan 44610, Republic of Korea.
² Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan 44919, Republic of Korea.
³ Department of Physics, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107 South Korea.

PMID: 34374510
DOI: 10.1021/acsami.1c08139

Abstract

In this study, a facile approach has been successfully applied to synthesize a W-doped Fe₂O₃/MoS₂ core-shell electrode with unique nanostructure modifications for photoelectrochemical performance. A two-dimensional (2D) structure of molybdenum disulfide (MoS₂) and tungsten (W)-doped hematite (W:α-Fe₂O₃) overcomes the drawbacks of the α-Fe₂O₃ and MoS₂ semiconductor through simple and facile processes to improve the photoelectrochemical (PEC) performance. The highest photocurrent density of the 0.5W:α-Fe₂O₃/MoS₂ photoanode is 1.83 mA·cm^-2 at 1.23 V vs reversible hydrogen electrode (RHE) under 100 mW·cm² illumination, which is higher than those of 0.5W:α-Fe₂O₃ and pure α-Fe₂O₃ electrodes. The overall water splitting was evaluated by measuring the H₂ and O₂ evolution, which after 2 h of irradiation for 0.5W:α-Fe₂O₃/MoS₂ was determined to be 49 and 23.8 μmol.cm^-2, respectively. The optimized combination of the heterojunction and metal doping on pure α-Fe₂O₃ (0.5W:α-Fe₂O₃/MoS₂ photoanode) showed an incident photon-to-electron conversion efficiency (IPCE) of 37% and an applied bias photon-to-current efficiency (ABPE) of 26%, which are around 5.2 and 13 times higher than those of 0.5W:α-Fe₂O₃, respectively. Moreover, the facile fabrication strategy can be easily extended to design other oxide/carbon-sulfide/oxide core-shell materials for extensive applications.

Keywords: MoS2 nanosheets; charge separation; donor concentration; hematite nanorods; photoelectrochemical (PEC) cells.