Research

Areas:
Materials/Electrochemistry/Engineering
Key words:
2D transition metal dichalcogenides; in-situ TEM; Energy and environmental applications

We are focusing on using In-situ/Ex-situ Multimodal Characterizations (especially in-situ TEM, synchrotron X-ray absorption, electrochemical testing etc.) to solve fundamental and technologically-important problems, especially those related with energy and environmental applications. We have been working on diverse research projects, such as nanomaterial synthesis, in-situ TEM study, electronics devices, catalysis, batteries, sensors, etc. Our group develops a versatile and interdisciplinary research, ranging from material syntheses, to structures, properties, and to applications.

Our innovative experimental methodology and advanced material characterizing platform not only can explore a new research field and help researcher from academic filed understand and design material more effectively, but also can inspire or illuminate engineers in industrial filed for technology innovation. For instance, our universal 2D nanosheets preparation method, which is accomplished through systematic battery intercalation strategy, has been proved to be an economic, high yield, mass production material synthesis method. The method is follow by many researchers (Citation 1527) as well as engineer’s connection from Samsung Company. Our advanced electrochemical liquid cell platform opened a venue by which to look inside the electrochemistry at atomic level, which attracted Toyota Company engineers’ attention asking for cooperation.

Battery intercalation for material synthesis, mechanism study and energy applications

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Our group developed a general and effective method for two dimensional nanosheets preparation by using a battery intercalation strategy, such as MoS2, WS2, TiS2, TaS2, ZrS2 and graphene, which was proved to be efficient method for high yield, excellent quality of 2D nanosheets preparation. Then, we extended the controllable lithium intercalation and exfoliation into other types of inorganic layered compounds, and few layer BN, NbSe2, WSe2, Sb2Se3 and Bi2Te3 nanosheets were successfully prepared.

Failure mechanism study of Li-ion batteries using in-situ/ex-situ characterizations

We developed an in-situ electrochemical liquid cell TEM technique to real time capture lithium dendritic growth, electrolyte decomposition, and solid electrolyte interphase (SEI) formation. By developing a self-designed electrochemical liquid cell, we can directly vapture the dynamic electrochemical lithiation and delithiation of electrode in a commercial electrolyte. This method sheds lights on strategies of addressing batteries failures, improving batteries design and also enabling the nextgeneration energy storage systems.

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Rational design of MnO2‐Based Materials for Environmental Applications

Manganese dioxide (MnO2) is a promising photo–thermo–electric‐responsive semiconductor material for environmental applications, owing to its various favorable properties. We would like to improving the environmental purification efficiency of MnO2‐based composites by morphology control, structure construction, facet engineering, element doping, homojunctions and heterojunctions construction. Their applications in environmental purifications can be as an adsorbent material for removing heavy metals, dyes, and microwave (MW) pollution, or as a thermal catalyst, photocatalyst, and electrocatalyst for the degradation of pollutants.

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Rational design of 2D transition metal dichalcogenides composites for HER

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To design an effective HER catalyst, we can synthesize large amount of single layer TMD nanosheets in 1T phase through battery intercalation strategy, since the electrochemical exfoliated MoS2 leads to favorable kinetics, metallic conductivity, and proliferation of active sites in the exfoliated 1T-MoS2 nanosheets. We can also  introduce large amounts of intensive catalytic points, through epitaxial growth of locally high-curvature noble metal nanoparticles on TMD nanosheets.