Atomic Layer Deposition of MoS2 Decorated TiO2 Nanotubes for Photoelectrochemical Water Splitting. Issue 20 (17th June 2022)

• Record Type: Journal Article
• Authors: Shen, Chengxu; Wierzbicka, Ewa; Schultz, Thorsten; Wang, Rongbin; Koch, Norbert; Pinna, Nicola
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-17
• Subjects: atomic layer deposition -- solar fuels -- titania nanotubes -- water splitting; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202200643
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: A thermal atomic layer deposition (ALD) process to fabricate MoS2 thin films is successfully demonstrated by using cycloheptatriene molybdenum tricarbonyl (C7 H8 Mo(CO)3 ) and H2 S as precursors at an ALD temperature below 300 °C. The process is systematically investigated, showing a typical self‐limiting characteristic within an ALD temperature window of 225–285 °C and a high growth‐per‐cycle of 0.11 nm. The as‐deposited films are amorphous while they can be crystallized in situ by sulfurization with H2 S at a low temperature of 300 °C. A prototypical application of the developed ALD process is demonstrated by constructing a MoS2 /TiO2 heterostructure through depositing MoS2 onto anodized TiO2 nanotubes for photoelectrochemical water splitting. The MoS2 /TiO2 heterostructures exhibit approximately three times superior photoelectrochemical performance than the pristine TiO2 nanotubes. This is attributed to an enhanced visible light‐harvesting ability of MoS2 and an improved separation of the photo‐generated charge carriers at the heterostructure interface, which is affirmed by a staggering gap (type II) between MoS2 and TiO2 as probed by ultraviolet photoelectron spectroscopy. Abstract : A low‐temperature atomic layer deposition (ALD) process is successfully developed using cycloheptatriene molybdenum tricarbonyl (C7 H8 Mo(CO)3 ) and H2 S as precursors, followed by mild‐temperature (300 °C) sulfurization with H2 S. The MoS2 /TiO2 heterostructure is constructed by homogeneously coating the MoS2 onto TiO2 nanotubes with the established ALD process, demonstrating a type‐II staggering gap and improved photoelectrochemical water splitting performance.