title: Large-area synthesis of monolayered MoS(2(1-x))Se(2x) with a tunable band gap and its enhanced electrochemical catalytic activity.
abstract: "Band gap engineering" in two-dimensional (2D) materials plays an important role in tailoring their physical and chemical properties. The tuning of the band gap is typically achieved by controlling the composition of the semiconductor alloys. However, large-area preparation of 2D alloys remains a major challenge. Here, we report the large-area synthesis of high-quality monolayered MoS2(1-x)Se2x with a size coverage of hundreds of microns using a chemical vapor deposition method. The photoluminescence (PL) spectroscopy results confirm the tunable band gap in MoS2(1-x)Se2x, which is modulated by varying the Se content. Atomic-scale analysis was performed and the chemical composition was characterized using high-resolution scanning transmission electron microscopy and X-ray photoemission spectroscopy. With the introduction of Se into monolayered MoS2, it leads to enhanced catalytic activity in an electrochemical reaction for hydrogen generation, compared to monolayered MoS2 and MoSe2. It is promising as a potential alternative to expensive noble metals.
authors.affiliation: Department of Materials Science & Engineering, CAS Key Lab of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Qi
authors.initials: Q
authors.lastname: Fu
authors.forename: Wenhui
authors.initials: W
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Jianliu
authors.initials: J
authors.lastname: Huang
authors.forename: Jingyu
authors.initials: J
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Xiang