Ya-Chu Yu

Bio: Ya-Chu Yu is an academic researcher from Tunghai University. The author has contributed to research in topics: Molybdenum disulfide & Hybrid physical-chemical vapor deposition. The author has an hindex of 2, co-authored 2 publications receiving 2947 citations.

Synthesis of Large‐Area MoS2 Atomic Layers with Chemical Vapor Deposition

Abstract: Large-area MoS(2) atomic layers are synthesized on SiO(2) substrates by chemical vapor deposition using MoO(3) and S powders as the reactants. Optical, microscopic and electrical measurements suggest that the synthetic process leads to the growth of MoS(2) monolayer. The TEM images verify that the synthesized MoS(2) sheets are highly crystalline.

Facile synthesis of MoS2/graphene nanocomposite with high catalytic activity toward triiodide reduction in dye-sensitized solar cells

Abstract: In the current study, a nanocomposite of molybdenum disulfide and graphene (MoS2/RGO) was proposed for the first time as the counter electrode (CE) catalyst in dye-sensitized solar cells (DSSCs) to speed up the reduction of triiodide (I3−) to iodide (I−). This novel catalyst was synthesized by simply mixing graphene oxide nanosheets with a solution of ammonium tetrathiomolybdate and then converting the solid intermediate into MoS2/RGO nanocomposite in a H2 flow at 650 °C. Atomic force microscopy, X-ray powder diffraction and X-ray photoemission spectroscopy confirmed that MoS2 nanoparticles were deposited onto the graphene surface. The extensive cyclic voltammograms (CV) showed that the cathodic current density of the MoS2/RGO CE was higher than those of MoS2, RGO and sputtered Pt CEs, due to the increased active surface area of the former. Moreover, the peak current densities of the MoS2/RGO CE showed no sign of degradation after 100 consecutive CV tests, suggesting the great electrochemical stability of the MoS2/RGO CE. Furthermore, the MoS2/RGO CE demonstrated an impressively low charge-transfer resistance (0.57 Ω cm2) for I3− reduction. Finally, the DSSC assembled with the MoS2/RGO CE showed a high power conversion efficiency of 6.04%, which is comparable to the DSSC with a Pt CE (6.38%).

The Methodological-obtained Derivant of ZIF-67 Metal-organic Frameworks Present Impressive Supercapacitor Performance

Abstract: Metal-organic framework (MOF)-derived hybrids are promising electrode materials for electrochemical energy storage due to their high surface area which provided plentiful redox sites and excellent electrical conductivity compared with fresh...

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets

Abstract: Ultrathin two-dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono- or few-layered TMDs - obtained either through exfoliation of bulk materials or bottom-up syntheses - are direct-gap semiconductors whose bandgap energy, as well as carrier type (n- or p-type), varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto-electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li-ion batteries and supercapacitors.

Progress, Challenges, and Opportunities in Two-Dimensional Materials Beyond Graphene

Abstract: Graphene’s success has shown that it is possible to create stable, single and few-atom-thick layers of van der Waals materials, and also that these materials can exhibit fascinating and technologically useful properties. Here we review the state-of-the-art of 2D materials beyond graphene. Initially, we will outline the different chemical classes of 2D materials and discuss the various strategies to prepare single-layer, few-layer, and multilayer assembly materials in solution, on substrates, and on the wafer scale. Additionally, we present an experimental guide for identifying and characterizing single-layer-thick materials, as well as outlining emerging techniques that yield both local and global information. We describe the differences that occur in the electronic structure between the bulk and the single layer and discuss various methods of tuning their electronic properties by manipulating the surface. Finally, we highlight the properties and advantages of single-, few-, and many-layer 2D materials in...

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

Abstract: Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...