2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 1

2014/04/10

introduction of Professor Ohtani Laboratory

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 2

Advanced Course in Photocatalytic Reaction Chemistry

understanding chemistry by understanding photocatalysisunderstanding photocatalysis by understanding chemistry

Division of Environmental Material Science, Graduate School of Environmental ScienceThe first semester of Fiscal 201408:45─10:15, Thursday at Lecture Room D103

Bunsho Ohtani, Ewa Kowalska and Mai Takase

Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan011-706-9132 (dial-in)/011-706-9133 (facsimile)

ohtani@cat.hokudai.ac.jphttp://www.hucc.hokudai.ac.jp/~k15391/

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 3

objectives/goal/keywords

<< objectives >>Understanding the mechanism of decomposition of pollutants, methodsof photocatalysts preparation, design of practical photocatalytic reactionsystems, and strategy for enhancement of photocatalytic activity.

<< goal >>To understand principle of photocatalytic reaction from the standpointof chemistry and strategy for practical applications. To obtain scientificmethod for research on functional solid materials.

<< keywords >>Photocatalyst, Photoinduced oxidative decomposition, Superhydro-philicity, Excited electron-positive hole, Structure-activity correlation,Higher photocatalytic activity, Visible-light response

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schedule

(1) April 10 introduction of photocatalysis(2) April 17 interaction between substances and light(3) April 24 electronic structure and photoabsorption(4) May 1 thermodynamics: electron and positive hole(5) May 8 adsorption(6) May 15 (Professor Ewa Kowalska)(7) May 22 kinetic analysis of photocatalysis (8) May 29 steady-state approximation(9) June 5 kinetics and photocatalytic activity(10) June 12 kinetic analysis(11) June 19 (Professor Mai Takase)(12) June 26 action spectrum analysis (1)(13) July 3 action spectrum analysis (2)(14) July 10 crystal structure of titania(15) July 17 design and development of photocatalysts

July 24 deadline for submission of special report

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comments on this lecture

Please send email in Japanese or English within 48 hours

to: ohtani@cat.hokudai.ac.jpsubject: pc2014MMDD-XXXXXXXXbody:

(full name)(nickname)(comments and/or questions on today's lecture)

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 6

Hokkaido University: A National University

Hokkaido: A northern island of Japan

Sapporo: A capital city of Hokkaido Prefecture

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 7introduction 7

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 8

Catalysis Research Center, Hokkaido Univ.

Catalysis Research Center

Unique research institute for studies on catalysis, including photocatalysis, in Japan, previously Institute for Catalysis.Twenty faculty members including seven full professors.

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Catalysis Research Center (CRC)

Catalysis Research Center (CRC) originate from Institute for Catalysiswhich was founded in 1943 in Hokkaido University for fundamental studieson catalysis, and started as a national collaborating institution in 1988,followed by scale-up reorganization in 1998 and by reorganization renewalin 2007 for playing a leading role in catalysis studies and a bridging roleamong interdisciplinary research fields.

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Catalysis Research Center

9 Professors (K. Asakura/M. Osawa/B. Ohtani/W. Ueda/A. Fukuoka/T. Takahashi/T. Nakano/J. Hasegawa/M. Nishida)

7 Associate professors 7 Assistant professors29 Research fellows5 Visiting professors19 Collaborative researchers58 Students13 Tentative staff8 Technical staff20 Administrative staff173 Total

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CRC: Divisions and Clusters

Target-Oriented R

esearch Assem

blyTarget-O

riented Research A

ssembly

Professor Associate Professor

触媒理論化学研究部門

触媒理論化学研究部門

Fundamental Research DivisionFundamental Research Division

実用化基盤技術開発部

実用化基盤技術開発部

コーポレートユニット

コーポレートユニット

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2010 Nobel Prize in Chemistry

Professor Akira SUZUKI (Professor Emeritus, Hokkaido University)

Professor Ei-ichi NEGISHI(Purdue University)

These two professors are also Specially Invited Professors in Catalysis Research Center, Hokkaido University

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titania-coated glass of our building

• all glass plates are coated with titania to reduce infrared radiation (with expectation to keep the surfaces clean).

• coated on site; not construction with pre-coated glass plates• expected photocatalytic self-cleaning effect

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to be a world number one labo on photocatalysis

photocatalysis

URL of web page for Professor OhtaniLaboratoryhttp://www.hucc.hokudai.ac.jp/~k15391/

光触媒 研究室 検索

"photocatalysis" and "laboratory"

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critical reviews

critical reviews on, not a compilation of, photocatalytic studies

Open paper: free of charge for downloading the PDF file

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Photocatalysis A to Z [JPPC, 11 (2010) 157-178]

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Ohtani Laboratory for photocatalysis research

collaboration work using advanced instruments designed for photocatalysis

research

collaboration work using advanced instruments designed for photocatalysis

research

evaluation of photocatalytic activitiesevaluation of photocatalytic activities

education for young people education for young people

opened for researchers in academics and industriesopened for researchers in academics and industries

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single-author books

Hikarishokubai no Shikumi ga Wakaru HonHikarishokubai Hyojun Kenkyuho (Scientific Methods in Photocatalysis)

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Professor Ken-ichi Fukui

October 19, 1981: announcement of Nobel Prize in ChemistryJanuary 9, 1998: died

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questions

Q Have you heard or seen a term "photocatalysis" (or "photocatalyst") before attending this class?

Q Do you know the examples of practical applications of photocatalysis? Interpret the mechanism.

Q What is the meaning of "catalyst (or catalysis)" in a term "photocatalyst"?

introduction of photocatalysis

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photocatalysis: two major phenomena

photocatalytic decompositiontarget:

organic compoundssteins (oil)microorganisms

photocatalytic decompositiontarget:

organic compoundssteins (oil)microorganisms

photoinduced (super) hydrophilicitywashable with running wateranti-fogging

photoinduced (super) hydrophilicitywashable with running wateranti-fogging

mechanism

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regular PVC Teflon-coated titania-coated

after exposure outdoor for 5 months

showing change in

color

Taiyo Kogyohttp://www.taiyokogyo.co.jp/

tent material coated with titania photocatalyst

PVC must contain organic additives, which go out to the surface slowly, to be elastic.

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titania-coated glass of our building

• all glass plates are coated with titania to reduce infrared radiation (with expectation to keep the surfaces clean).

• coated on site; not construction with pre-coated glass plates• expected photocatalytic self-cleaning effect

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 24

substrate: steal plates

JFE Building Materialshttp://www.jfe-kenzai.co.jp/index.shtml

exterior materials coated with titania

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with

paints requiring no heating: room-temperature coating

titania photocatalytic painting

painting procedure with brush or roller

painting procedure:spraying

withoutwith

without

with without

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large-scale application of photocatalysts"self-cleaning" window glasses

"Marubiru", a large office building in Tokyo

"Centrea", Chubu International airport, Nagoya

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inside: anti-fogging effect to give water droplet-free surfaceoutside: photocatalytic decomposition and (super) hydrophilicity to

keep the surface clean

photocatalyst coated glass

Japan Hydrotect Coatings

regular glass

titania-coated glass

on-site coating > pre-coating

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Nippon Sodahttp://www.nippon-soda.co.jp/photo/report.html

titania coatings with heating = pre-coating window blinds

titania photocatalyst-including paint

No effect of photo-induced hydrophilicity is expected for indoor use.

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"partition" with photocatalytic coatings

possible effects:cleaning by decomposition of organic matters/deodorization/anti-microorganisms

Mitsubishi Plasticshttp://www.mpi.co.jp/press/pr030501.htm

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titania-coatings for anti-fogging

TOTO

regularpart

titaniacoatedpart

no water droplets due to the (super) hydrophilicity of photocatalytic titania surface

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polycarbonate plates covered withtitania photocatalyst on both sides

Sekisui Plasticshttp://www.sekisuijushi.co.jp/

road-side sound barriers coated with titania

titania1.5 year

regular1.5 year

regular3.5 year

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pavements containing titania photocatalyst

"Photoroad"

Nitrogen oxides (NOx) are oxidized by photocatalystResulting nitrate (NO3

-) ions are captured by calcium ionsCalcium nitrate (Ca(NO3)2) is washed out by rain water

Fujitahttp://www.fujita.co.jp

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Toshiba Lightechttp://www.tlt.co.jp/tlt/new/crean/crean.htm

a covering window glass coated with titania

lights for outdoor use

regularfluorescent lamp

lighting device with titania photocatalyst

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photocatalytic air purifier unit

active air purification: decontamination and deodorization of circulating air

Hitachi Home and Life Solutionhttp://www.hitachi-hl.com/

Daikin Ltd.http://www.daikinaircon.com/

air conditionerair conditioner

air purifierair purifier

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photocatalytic treatment of water

Sumitomo Metal Industrieshttp://www.sumitomometals.co.jp/news/monthly/2001/140.html

polluted gas

drain

aeration unit

water

exhaust

pump

soil

groundwater

air

dryerseparator photocata-lyst

neutra-lizer

decontaminated

polluted gasblack light

flow apparatus

Contaminated ground water is treated to remove volatile organic compounds.

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smoke cleaner/refrigerator

Toshiba/Mitsubishihttp://www.toshiba.co.jp/about/press/2001_09/pr_j0302.htmhttp://www.mitsubishielectric.co.jp/news/2009/0825-a.htm

Toshiba/Mitsubishihttp://www.toshiba.co.jp/about/press/2001_09/pr_j0302.htmhttp://www.mitsubishielectric.co.jp/news/2009/0825-a.htm

deodorization/decomposition of ethylene (CH2=CH2) from vegetables/fruits to keep freshness

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photocatalytic water treatment

photocatalytic fiber cartridge for decomposition of dioxin and sterilization

UBE Industrieshttp://www.ube-ind.co.jp/japanese/japanese/annai/01_05_03.htm

チタニアが有機物を酸化分解する光触媒機能に着目して、接触面積が大きく、丈夫な繊維状にしたのが『光触媒繊維』。既存の光触媒製品と差別化した製品の特色を活かして市場開発を進めています。この新素材はダイオキシンの分解にも期待されています。

チタニアが有機物を酸化分解する光触媒機能に着目して、接触面積が大きく、丈夫な繊維状にしたのが『光触媒繊維』。既存の光触媒製品と差別化した製品の特色を活かして市場開発を進めています。この新素材はダイオキシンの分解にも期待されています。

2014/04/10—Advanced Course in Photocatalytic Reaction Chemistry 38

a TOC analyzer with a photocatalytic reactor

Hiranuma Industrieshttp://www.hiranuma.com/products/envr/toc/Hiranuma Industrieshttp://www.hiranuma.com/products/envr/toc/

• Analyzing TOC (total organic carbon), organic compounds are decomposed by oxidantsinto carbon dioxide (CO2) and the amount of CO2 is measured.

• Conventional analyzers require the use of potassium permanganate as an oxidant or ofa expensive short-wavelength (254 nm) mercury arc lamp.

• Using a titanium(IV) oxide photocatalyst system, any chemicals and their posttreatment are not needed and cheaper long-wavelength mercury arc lamps can beused.

TOC-3000TOC-3000

TOC-2000TOC-2000

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photocatalysis industries in Japanindustries related to photocatalysisalmost 300 million USD after 2005(Photocatalysis Industry Association of Japan)

otherslivingwarecleanuproadinteriorexteriorm

illio

n U

SD

400

300

200

100

02000 2002 2004 2006 2008

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photocatalysis industries in Japan2012 (2011): ca. 400 million USD [370 million USD for 2011]

47(52)%

2(1)%

3(4)%

43(38)%

4(4)%

exteriorexterior

interiorinteriorroad relatedroad related

purifierpurifier

living wareliving ware

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photocatalysis: two major phenomena

superhydrophilicity: the surface of photocatalytic (titania) coatings becomes super hydrophilic, i.e., contact angle to be almost zero.

photocatalytic oxidation: organic and inorganic compounds are oxidized under air to be inorganic materials, i.e, mineralization.

left: photocatalytic/right: ordinaryleft: photocatalytic/right: ordinary

mechanism

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titanium(IV) oxide (titania) as a photocatalyst

no change after reaction = "catalyst"

no reaction in the dark = "safe" and environ-mentally benign

very popular and cheap material

especially strong oxidizing power when irradiated

white or colorless = no effect on appearancebut, requires ultraviolet irradiation

highphoto-

stability

superiorredox ability availability

notpoisonous& natural

titanium(IV) oxideTiO2

titania

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practical applications

Q Which application impressed you the most? What is the reason for that?

Q What is the general chemical reaction(s) included in the practical applications of photocatalysis? Show a reaction formula(s).

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comments on this lecture

Please send email in Japanese or English within 48 hours

to: ohtani@cat.hokudai.ac.jpsubject: pc20140410-XXXXXXXXbody:

full namenicknamecomments (questions) on this lectureorder of book(s) if any JPY1,200 (77%) JPY3,500 (79%)

pc20140410-12345678