Welcome to Noda-Hanada Lab's Home Page

Japanese

Nanomaterials & Self-Organization

Nanotechnology brings innovations to the society in wide fields of energy/environment, information/communication, etc., by adding novel functions to materials by controlling their structures at nanometer-scale. We are trying to establish the base of materials nanotechnology.

Let us think about the future clean energy systems. For large-scale electric power generation by solar cells, efficient use of high purity silicon is the key. We are trying to improve the efficiency several-ten times by making highly-crystalline films in one minute instead of bulk substrates. Transparent electrodes are important for both solar cells (yielding electricity from light) and display & lighting devices (generating lights from electricity). We try to replace rare-metal-based oxide semiconductors with carbon nanotubes or graphene. Nanotube-silicon hybrids are promising to realize Li ion batteries of larger capacities for (hybrid) electric vehicles. In this way, nanotechnology can bring innovations widely even with abundant carbon and silicon elements, and contributes to sustainable technological society.

But nanomaterials can never be made in macro-scale if we artificially manipulate atoms/molecules one-by-one. Self-organization, i.e. spontaneous formation of materials from numerous atoms/molecules, is the key. We are trying to understand the processes of chemical reactions of atoms/molecules, formation of nanostructures, and evolution of higher-order structures fundamentally. Based on the fundamental understandings with flexible thinking and idea, we are proposing and developing novel processes for nanomaterials and their devices.

Carbon Nanotubes

Carbon nanotubes (CNTs) are a unique 1D nanomaterial as thin as ~nm and as long as ~mm. They have good electrical conductivity, high tensile strength, thermal and chemical stability similarly with inorganic materials, and have small mass, flexibility, and compatibility with printing process similarly with organic materials. Thus, many applications have been proposed for them.
On the other hand, as their price (higher than gold) shows, their fabrication process is still under development and their practical applications are very much limited. Chemistry & engineering should lead the innovations for their production and manufacturing. We have developed rapid growth process of millimeter-long single-wall CNTs and are trying to realize their practical production. Please click here for details.
We are developing mass-production processes of CNTs by utilizing three-dimensional space of reactors, and direct fabrication of various devices by growing CNTs on device substrates. We have also started the synthesis of boron nitride nanotubes (BNNTs) having similar structure as CNTs and insulative property.
  • Jianghua LANG (PD): Stable and continuous synthesis of carbon nanotubes by floating catalyst CVD with fluid mixing control.
  • Pengfei CHEN (D3): Activation of alkane for CVD synthesis of CNTs.
  • Wataru KITAHARA (M2): Morphology control of vertically aligned CNT films afor small X-ray tubes with enhanced life.
  • Shun TANAKA (M1): Development of a safe and low-damage dry purification method for CNTs.
  • Yuki NAOTSUKA (M1): Stable and continuous synthesis of carbon nanotubes by floating catalyst CVD with enhanced decomposition of catalyst sources
  • Daiki KITAJIMA (B4): Coating of carbon nanotube with boron nitride for lithium-ion battery application.

Rapid SWCNT growth
Larger Movie.


Continuous production by fluidized bed: Movie

Functional Films

In many devices made of solids, the interface between solids often governs performance. As the performance of electrical and electronic devices increases dramatically, the density of energy input into the device increases, and how to dissipate the heat generated is an important issue. On the other hand, LEDs and sensors are mounted on various devices such as automobiles, and their anti-fog and anti-snow protection is also becoming important. Various types of thin films are required to connect solid interfaces and add functionality to surfaces.
Strong chemical bonds create stiffness as well as heat resistance and chemical stability in ordinary bulk materials. On the other hand, CNTs and BNNTs are thin, one-dimensional materials with diameters of a few nm that have flexibility with strong and stable chemical bonds. They also have a large specific surface area and van der Waals interactions between nanotubes, which intertwine with each other in a sponge-like free-standing film. The material with unique features of softness, thermal stability, and thermal conductivity can be produced, and is expected to have diverse applications in solar cells, in-vehicle devices, and semiconductor device manufacturing.
Evaporation of solids in an inert gas such as Ar allows the synthesis of solid particulates with a clean surface, and these particulate films easily sinter and return to the bulk. We have created novel materials with high thermal stability once bonded while bonding at low temperatures.
  • Yoshihiro TAKAHASHI (M2): Low thermal resistance and high heat resistance interfacial bonding between solids.
  • Ryosuke NAKAJIMA (M2): Stable p/n-doping of carbon nanotubes
  • Naoumi HASUMI (M2): Development of CNT transparent heater by spray coating and liquid surface transfer.
  • Koyo ANDO (B4): Synthesis of CNTs by floating catalyst CVD method and development of transparent thin films.
  • Sakurako TACHIBANA (B4): Low-damage high-yield dispersion and filtration of CNTs to develop transparent thin films.
  • Kentaro NAKA (B4): Creation of metal aerogel films by gas evaporation and particle deposition for interface bonding.

1-min-epitaxy and lift-off of Si films for solar cells

Rechargeable batteries

Energy devices must be produced at low cost and installed at large scale in order to contribute to the sustainable energy and environmental systems.
We are developing next-generation, high energy and power density rechargeable batteries via rapid, high-yield fabrication process using low-cost sources. Self-supporting, sponge-like films of single-wall and few-wall CNTs can be easily obtained by dispersion and filtration. For example, 0.1 mm-thick paper of our few-wall CNTs by fluidized-bed CVD is as light as 0.3 mg/cm3 and 3 mg/cm2, has a 80-90% porosity and 100 S/cm electrical conductivity. Differently from the conventional electrodes fabricated by coating active materials on heavy current collectors of Cu or Al foils with binder and conductive fillers, we are developing light-weight, high-capacity electrodes by capturing various active materials in the CNT papers.
Especially, Si has a huge theoretical capacity 10-times as large as the current graphite anode, however is suffering from the degradation due to the volumetric change during charge-discharge cycles. Vapor deposition is a common method in basic research in preparing thin films slowly and carefully under ultrahigh vacuum. But it enables rapid, low-cost fabrication of aluminum thin films for gas barriers in snack packaging in industry. We elevate the vapor pressure of the evaporation source by heating it to a temperature much higher than the melting point, deposit the vapor on substrates at lower temperature, and realize several micrometer-thick porous films quickly in 1 minute. We are applying this method also for various metals to realize high-performance battery electrodes via simple, low-cost processes.

1-min deposition of porous Si films for Li ion batteries

Hydrogen Energy

Hydrogen is expected as a clean secondary energy, which does not emit CO2 upon usage. Renewable energy is getting cheaper drastically, and large-scale production of CO2-free hydrogen is expected in future. However, breakthrough still is needed in its storage and transportation for their efficient use for production of energy and chemicals. Various technologies such as hydrogen storage alloys and hydrogen carriers have been researched, in which the chemical conversion of hydrogen via interfacial reaction is important. We are developing new materials by hybridization of hydrogen storage alloys and electrocatalysts with carbon nanotubes, and apparatuses and processes based on those materials.

CO2-absorbing concrete

Concrete is indispensable for the construction and maintenance of social infrastructure, but the production of cement emits large amounts of greenhouse gases (5% of Japan's total and 8% of the world's total). This is because CaCO3 is heated by burning fossil fuels to form a compound of CaO and SiO2, which then reacts with H2O to harden as Ca(OH)2, producing a large amount of CO2 in terms of both material and energy. Recently, CO2-absorbing cement materials have been developed that hardens to CaCO3 through the reaction of CaO and CO2. CaCO3 is also the main ingredient of marble and is characterized by its high strength and stability. If CaO, a by-product of blast furnace slag and incinerator ash, is used as a raw material, it may be possible to shift from emissions to absorption of CO2. However, since this reaction is slow. To put it into wide practical use, it is essential to develop reaction acceleration technology based on the clarification of the reaction mechanism. Although this is a complex reaction in a gas-liquid-solid system, we are working on research and development based on our unique approach, utilizing our knowledge of chemical engineering, reaction engineering, and material processes.
  • Katsuya NAMIKI (Research Associate): In-situ reaction analysis and CO2-fixation evaluation of CO2 absorbing concrete using a batch reactor.
  • Yuli WEN (PD): In-situ reaction analysis and CO2-fixation evaluation of CO2 absorbing concrete using a flow reactor.
  • Misuzu TAKASE (M2): Detailed analysis of CO2 absorption reaction of ƒÁ-2CaO„SiO2.
  • Daisuke MOTOHASHI (M1): Reaction analysis of ƒÁ-2CaO„SiO2 based CO2 absorbing cement admixture as powder
  • Ruri MATSUI (B4): Analysis of rate and mechanism of CO2 absorption by Ca2SiO4 particles mixed with inert particles.
  • Yuya YOKOI (B4): Analysis of rate and mechanism of CO2 absorption by Ca2SiO4 particles mixed with inert particles.
  • Assessment of Emerging Technologies

    Extensive efforts and budgets are being paid to research and development in application fields. However, the rapid expansion of knowledge and technology has resulted in excessive specialization of fields, complication of systems, and distance between technology and society, sometimes causing the technologies unused even when they are successfully developed. Subjective research and development are inefficient and insufficient. It is essential to assess the technologies quantitatively by setting them to systems and estimating the performance change of the systems in society, comparing them with existing/competitive technologies objectively, and making feedback the results to research and development. It is important to shift from the ggood mattersh to guseful mattersh, develop methodologies and theories, and cultivate professionals.
    We are developing new technologies for innovations in fields including energy and environment, and trying to conduct development and assessment of emerging technologies concurrently.
    • Zih-Ee LIN (PD): Multidimensional assessment of electricity supply system combining renewable energy and second-life lithium-ion batteries.
    • S. NATARAJAN (PD): Environmental impact assessment of recycling various components of spent lithium-ion batteries.
    • Yihua TANG (PD):
    • Tomotaro MAE (Lecturer): Environmental impact assessment of CNT-Based SiO||NCM batteries.
    • Ben HUANG (D3): Environmental impact assessment of direct recycling of NCM cathode materials from spent lithium-ion batteries.
    • Ryota ZUKERAN (M2): Evaluation of greenhouse gas emissions from hydrogen utilization systems using hydrogen storage alloys.
    • Luke MURAKAMI (M2): Evaluation of greenhouse gas emissions from hydrogen utilization systems using liquid ammonia electrolysis.
    • Misuzu TAKASE (M1), Daisuke MOTOHASHI (M1): Assessment of greenhouse gas emissions including transportation of CO2-absorbing concrete.
    • Kebei CHEN (B3), Sungjun KIM (B3): Scientific research.

    Previous Ph. D. Theses

    Previous Master Theses

    Previous Bachelor Theses

    Previous versions of this page

    current version | AY2023 | AY2022 | AY2021 | AY2020 | AY2019 | AY2018 | AY2017 | AY2016 | AY2015 | AY2014 | AY2013 | AY2012
    Noda-Hanada Laboratory,
    Department of Applied Chemistry,
    School of Advanced Science and Engineering,
    Waseda University,
    3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan