Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
  • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
  • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
  • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
  • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B1/00—Electrolytic production of inorganic compounds or non-metals
  • C25B1/01—Products
  • C25B1/13—Ozone
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
  • Y10T428/12063—Nonparticulate metal component

Definitions

• the present invention relates generally to the generation of ozone.
• the present invention relates to an electrode material for generating ozone and a method of making the electrode material.
• the present invention also relates to a high concentration of dissolved ozone and an ozone generation system for generating the same.
• Ozone has many industrial applications, such as destructing organic and inorganic contaminants in wastewater and sludge, households disinfectants, swimming pools and hospitals, bleaching paper, etching semiconductor surfaces, decolorizing water, removing odor from clothing, and terminating pests. [See, Bruno Loire, David A. Reckhow, Deborah R. Brink; Ozone in Water Treatment application and Engineering, Lewis Publishers, INC. 1991, and references discussed therein.] Chlorination is commonly used in similar applications but will leave undesirable chlorinated organic residues. Ozone on the other hand will self disappear in time and leaves fewer potentially harmful residues.
• the first type of technology involves the corona discharge process, wherein ozone is formed from oxygen in air by the corona discharge in an intense and high frequency alternating electric field.
• This type of technology gives low ozone concentration (about 2% to oxygen) and can produce harmful nitrogen oxides.
• the generation of ozone is in the gas phase and to obtain dissolved ozone, the gaseous ozone is brought into contact with water and the amount of dissolved ozone is limited by the gas phase ozone concentration and the solubility.
• the other type of ozone generation technology is an electrochemical and electrolytic process, wherein water is decomposed to ozone by passing an electric current through the electrodes immersed in an aqueous electrolyte. Since ozone is generated directly in water, this process can provide high concentration of ozone at a high current efficiency. Over 35% current efficiency has been reported at low temperatures of -30°C to - 65°C [see, P.C. Foller, C.W. Tobias, J. Electrochem. Soc, 129 (1982), 506]. A recent report discussed a 3.0 mg/1 concentration of dissolved ozone [see, Tatapudi and Fenton, J. Electrochem. Soc, 140 (1993) 3527].
• ozone is formed by electrolytic decomposition of water, represented by following equations:
• Platinum, alpha and beta-Pb0 2 , Pd, Au, Ru0 2 -DSA 5 s, and glassy carbon in different electrolytes have been considered and tested for ozone generation.
• Gold, Ru0 2 -DSA's, and glassy carbon have been found to have very low current efficiency (less 1%).
• Platinum shows a current efficiency from 6.5% to 35% at very low temperature of about -50°C. However the current efficiency falls to around 0.5% at room temperature. Obtaining a high current efficiency at a low temperature will require additional equipment and energy cost to make existing systems less efficient and convenient.
• Pb0 2 electrodes can produce ozone at a current efficiency of 13% at room temperature. However, such a process releases toxic Pb ions into electrolyte solution.
• Tin dioxide a non-toxic semiconductor
• Low current efficiency and instability had been reported when such tin dioxide was used for electrochemically generating ozone in concentrated sulfuric acid.
• the present invention can provide an electrode member.
• the electrode member can comprise a substrate member and a coating member.
• the substrate member can be made of a material selected from the group consisting of titanium, gold coated titanium and other inert conducting materials.
• the coating member can comprise a tin dioxide modified by antimony.
• the particles of Sn and Sb can be in an atomic ratio from about 6:1 to about 10:1. Additionally or alternatively, a predetermined amount of nickel can be added in the coating member.
• the coating member can comprise particles from about 3 nm to about 5nm in size.
• the electrode member of the present invention can be used for direct generation of ozone in water or through water into a gaseous state.
• the water can contain an electrolyte selected from the group consisting of
• the electrolyte can be present in a concentration from about 0.01 M to about 0.5 M.
• the present invention can also provide an ozone generation system comprising such an electrode member to generate ozone efficiently.
• the ozone generation system can comprise a solid polymer electrolyte, such as Nafion.
• ozone can be generated in pure water, without the need of dissolved ions.
• the present invention can further provide a dissolved ozone with a high concentration.
• Fig. 1 is a SEM surface morphology of an antimony doped Sn0 2 electrode member of the present invention
• Fig. 2 is a graph illustrating the aqueous ozone concentration as a function of electric charge
• Fig. 3 is a graph illustrating the instantaneous aqueous ozone concentration as a function of scan potential.
• electrode members and ozone generation systems embodying the principles of the present invention will now be described in detail.
• similar elements or components thereof are designated with reference numbers having the same last two digits; redundant description is omitted.
• the present invention can provide an electrode member.
• the electrode member can comprise a substrate member and a coating member.
• the substrate member can be made of a material selected from the group consisting of titanium, gold coated titanium and other inert conducting materials.
• the substrate member is made of titanium.
• the substrate member can be made of titanium and be spot-welded with a titanium wire. It will be appreciated that other materials of the substrate member are also within the scope of the present invention.
• the coating member can be made of various materials and in various forms.
• the coating member can comprise a tin dioxide.
• the coating member can comprise an antimony modified tin dioxide film.
• the coating member can comprise SnCl 4 - 5H 2 0 and SbCl 3 .
• the coating member can comprise a predetermined amount of nickel.
• the coating member can be in the form of a solution, before being affixed onto the substrate member. It will be appreciated that other materials and forms of the coating member are also within the scope of the present invention.
• the coating member can comprise particles of various sizes.
• the coating member can comprise connected particles of less than 5 nm in size.
• the connected particles can be from about 3 nm to about 5 nm in size. It will be appreciated that other sizes of the particles are also within the scope of the present invention.
• the coating member can comprise particles of various ratios.
• the particles of oxides of Sn and Sb can have an atomic ratio of more than 6:1.
• the particles of oxides of Sn and Sb particles can have an atomic ratio of less than 10:1.
• the particles of Sb and Ni can be in an atomic ratio of more than 4:1.
• the particles of Sb and Ni can be in an atomic raitio of less than 10:1. It will be appreciated that other ratios of the particles are also within the scope of the present invention.
• the electrode member can be made of titanium and coated with antimony doped tin dioxide with surface morphology composed of 3 to 5 nm particles connected and covering substantially the entire surface.
• the particles comprise Sn and Sb in a ratio from about 6:1 to about 10:1.
• the atomic ratio of Sn:Sb:Ni can be about 500:8:1.
• the electrode member can yield high concentration of dissolved ozone at room temperature with high current efficiency.
• the electrode member can be prepared in various manners.
• a substrate member and a coating member of various forms can be provided, which can be similar to those described above.
• the substrate member can be treated or otherwise prepared by various conventional methods.
• the substrate member can be etch cleaned in an acid solution and then rinsed and dried. It will be appreciated that other methods of treating or preparing the substrate member are also within the scope of the present invention.
• the substrate member can be affixed with the coating member in various manners.
• the substrate member can be sprayed with, dipped into, or otherwise coated with the coating member.
• the coating member can be sprayed with solution of 2.5 g SnCl 4 - 5H 2 0 and 0.025g SbCl 3 in 25 ml of ethanol-HCl mixture.
• the coating member can be dipped into 25 ml ethanol-HCl mixture solution of 2.75 g SnCl 4 - 5H 2 0 and 0.025g SbCl 3 It will be appreciated that other methods of affixing the coating member to the substrate member are also within the scope of the present invention.
• the coated substrate member can then be heat treated in various manners.
• the coated substrate member can be dried, such as at a temperature of about 100°C for about ten minutes.
• the coated substrate member can be calcined, such as at a temperature of about 520°C in air for 5 mins.
• the above coating, drying, and calcining steps can be repeated. In an exemplary embodiment, these steps can be repeat for 12 times. In another exemplary embodiment, these steps can be repeat for 20 times. It will be appreciated that other heating methods including heating temperatures and/or time periods are also within the scope of the present invention.
• the present invention can also provide a high concentration ozone material.
• approximately 35 mg/1 aqueous ozone can be provided with over 15% current efficiency.
• the 15% current efficiency only accounts for the dissolved ozone.
• such an aqueous ozone can be generated in a 6 min constant potential polarization at low electrolyte concentration at room temperate.
• a significant amount of gaseous ozone can be generated and distinctly detected by the normal smell test. The measurement of gaseous ozone can show a much high current efficiency.
• the solution with dissolved ozone can decolorize a dye such as indigo instantly. High overpotential of oxygen evolution was observed in cyclic voltammetry.
• an ozone generation system can be in the form of an electrochemical system for generating the high concentration ozone material.
• the electrochemical system can comprise a cell member for containing an electrolyte material of various forms.
• the electrolyte material can comprise SnCl 4 - 5H 2 0 and SbCl 3 in an ethanol-HCl mixture.
• ozone can be generated in pure water, without the need of dissolved ions. It will be appreciated that various other types of ozone generation systems are also within the scope of the present invention.
• the ozone generation system can adopt the electrode member of the present invention for generating the high concentration ozone.
• the electrode member can be used as a working electrode.
• the electrode member can be used as an anode member in a electrochemical system.
• the electrode member can be positioned on the bottom of the cell member.
• a constant potential can be applied to the electrode member, such as at room temperature.
• the constant potential can range from 1.5V to 3V with respect to a reference electrode. In an exemplary embodiment, the constant potential can be about 2.5V. It will be appreciated that various other forms of the ozone generation system are also within the scope of the present invention.
• titanium wire was first etch cleaned in a 10% boiled oxalic acid solution for 1 hour, then rinsed with distilled water and dried.
• An antimony doped Sn0 2 electrode member was prepared by a spray pyrolysis technique on the pretreated Ti substrate member.
• the spray solution was 2.5 g SnCl 4 - 5H 2 0 and 0.025g SbCl 3 in 25 ml of ethanol-HCl mixture.
• the resulting electrode member showed a compact smooth surface morphology with connected particles having a diameter of about 3 to 5 nm (see Fig. 1).
• the atomic ratio of Sn to Sb in the film is about 7:1 by ICP analysis.
• Ozone was generated in a cell with 3 ml 0.1 M HC10 4 .
• the prepared doped Sn0 2 electrode member was used as a working electrode member positioned on the bottom of the cell.
• a 0.8 cm 2 platinum sheet was used as a counter electrode member positioned at the up-region of the electrolyte.
• An Ag/AgCl member was used as a reference electrode member and positioned closer to the working electrode member.
• a constant potential (vs. the Ag/AgCl member) of 2.5V was applied to the working electrode member at room temperature.
• About 35 g/1 of ozone dissolved in the electrolyte was generated in about 6 min. (see Fig. 2).
• the ozone concentration was determined by UV absorption as well as a standard indigo method.
• An antimony doped Sn0 2 electrode was prepared by dipping a Ti substrate with the same area as described in Example 1 into 25 ml ethanol- HCl mixture solution of 2.75 g SnCl 4 - 5H 2 0 and 0.025g SbCl 3 . Before drying the dipped the Ti substrate at 100°C 5 excess solution on the substrate surface was removed to leave a thin uniform liquid layer on the substrate surface. The substrate member was calcined at about 520°C. The time periods for drying and calcining were the same as in Example 1. The above process was repeated 30 times. The surface morphology of the resulting electrode was similar to that shown in Fig. 1. The ratio of Sn to Sb in the film is about 10:1 by ICP analysis.
• Ozone was generated using the same system as in Example 1.
• Sn0 2 electrode was performed by cyclic voltammetry in a potential ranging from 1.5 V to 3 V (vs. the Ag/AgCl member) at the scan rate of 1 mV/s at room temperature.
• Fig. 3 shows the ozone generated against scan potential.
• a solution of 1 molar SnCl 4 - 5H 2 0, 0.016 molar SbCl 3 , and 0.002 molar NiCl 2 - 6H20 in absolute ethanol was used as the coating solution.
• a titanium sheet can be coated in the same manner by dip coating and pyrolysis, as described in Example 1. The coating and pyrolysis was repeated 7 times. The resulting Ni-Sb doped Sn0 2 coated electrode member was tested to give better ozone generation. The current efficiency can reached more than 25% at room temperature using 0.1 molar perchloric acid electrolyte and with applied electric potential of 2.2 V (vs. the Ag/AgCl member). The ozone generation and measurement was the same as described in Example 1.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
• Electrodes For Compound Or Non-Metal Manufacture (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=32869648

Family Applications (1)

Country Status (4)

Families Citing this family (10)

Citations (1)

Family Cites Families (17)

• 2004
  • 2004-02-13 CN CN2004800042865A patent/CN1751140B/zh not_active Expired - Fee Related
  • 2004-02-13 WO PCT/CN2004/000120 patent/WO2004072329A1/en active Application Filing
  • 2004-02-13 EP EP04710771A patent/EP1597415A4/en not_active Withdrawn
  • 2004-02-17 US US10/780,309 patent/US20040226829A1/en not_active Abandoned
• 2008
  • 2008-04-30 US US12/112,189 patent/US20080257750A1/en not_active Abandoned
• 2012
  • 2012-02-10 US US13/370,452 patent/US20120138479A1/en not_active Abandoned

Patent Citations (1)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events