Enhanced photoelectrochemical activity in the heterostructure of vertically aligned few-layer MoS2 flakes on ZnO

• Published in: Electrochimica acta Vol. 260; pp. 150 - 156
• Main Authors: Trung, Tran Nam, Seo, Dong-Bum, Quang, Nguyen Duc, Kim, Dojin, Kim, Eui-Tae
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.01.2018
• Subjects: Metal chalcogenides; MoS2; Photoanode; Photoelectrocatalysis; Photoelectrocatalysis; Photoanode; MoS2; Metal chalcogenides
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.11.089

Vertically aligned MoS2 flakes were grown on indium tin oxide (ITO) and ITO/ZnO substrates using metalorganic chemical vapor deposition. The thickness of MoS2 flakes was manipulated at the few-layer level (5–10), which is desirable for energy-storage and energy-conversion applications. For photoelectrochemical (PEC) cells, a few-layer flake photoelectrode yielded a considerably higher photocurrent density (930 μA/cm2 at 0.2 V) than a MoS2 thin-film photoelectrode (360 μA/cm2 at 0.2 V) due to the former's high density of active sites, slow intraband relaxation rate from excitonic states, and low defect density. Furthermore, the heterostructure of ZnO/MoS2 flakes exhibited a remarkably high photocurrent density of 1.6 mA/cm2 at 0.2 V and a long-term stability under the PEC operating conditions because of its enhanced photogenerated carrier separation and transfer. Thus, such a heterostructure is promising as an efficient, nontoxic, inexpensive, and earth-abundant PEC electrode. [Display omitted] •Vertically aligned growth of few-layer MoS2 flakes using MOCVD.•Manipulating MoS2 morphology from thin films to few-layer flakes.•Efficient and long-term stable photoelectrochemical activity of ZnO/MoS2 flakes.