Next Article in Journal
Photoreduction of Carbon Dioxide to Methanol over Copper Based Zeolitic Imidazolate Framework-8: A New Generation Photocatalyst
Previous Article in Journal
Environmental-Friendly Synthesis of Alkyl Carbamates from Urea and Alcohols with Silica Gel Supported Catalysts
Open AccessArticle

Mixed-Phase (2H and 1T) MoS2 Catalyst for a Highly Efficient and Stable Si Photocathode

1
Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Korea
2
Department of Chemical and Biomolecular Engineering, YonSei University, Seoul 120-749, Korea
*
Authors to whom correspondence should be addressed.
These authors contributed equally to this work.
Catalysts 2018, 8(12), 580; https://doi.org/10.3390/catal8120580
Received: 31 October 2018 / Revised: 14 November 2018 / Accepted: 16 November 2018 / Published: 23 November 2018
(This article belongs to the Section Photocatalysis)
We describe the direct formation of mixed-phase (1T and 2H) MoS2 layers on Si as a photocathode via atomic layer deposition (ALD) for application in the photoelectrochemical (PEC) reduction of water to hydrogen. Without typical series-metal interfaces between Si and MoS2, our p-Si/SiOx/MoS2 photocathode showed efficient and stable operation in hydrogen evolution reactions (HERs). The resulting performance could be explained by spatially genuine device architectures in three dimensions (i.e., laterally homo and vertically heterojunction structures). The ALD-grown MoS2 overlayer with the mixed-phase 1T and 2H homojunction passivates light absorber and surface states and functions as a monolithic structure for effective charge transport within MoS2. It is also beneficial in the operation of p-i-n heterojunctions with inhomogeneous barrier heights due to the presence of mixed-phase cocatalysts. The effective barrier heights reached up to 0.8 eV with optimized MoS2 thicknesses, leading to a 670 mV photovoltage enhancement without employing buried Si p-n junctions. The fast-transient behaviors via light illumination show that the mixed-phase layered chalcogenides can serve as efficient cocatalysts by depinning the Fermi levels at the interfaces. A long-term operation of ~70 h was also demonstrated in a 0.5 M H2SO4 solution. View Full-Text
Keywords: photoelectrochemical water splitting (PEC); molybdenum disulfide; atomic layer deposition (ALD); p-i-n heterojunction; pinch-off effect photoelectrochemical water splitting (PEC); molybdenum disulfide; atomic layer deposition (ALD); p-i-n heterojunction; pinch-off effect
Show Figures

Figure 1

MDPI and ACS Style

Joe, J.; Bae, C.; Kim, E.; Ho, T.A.; Yang, H.; Park, J.H.; Shin, H. Mixed-Phase (2H and 1T) MoS2 Catalyst for a Highly Efficient and Stable Si Photocathode. Catalysts 2018, 8, 580.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop