NAN0 MIXED METAL OXIDE THIN FILM PFIOTOCATALYST CONSISTING OF TITANIUM, INDIUM AND TIN 5 FIELD OF INVENTION 'I'he prcscnt invention is directed to a novel photocalalyst comprising nano tnclal oxides of titanium, Indium atid tin as a thin film with llano sized grains atid the method of its preparation. The photocatalyst disclosed lhcrcin can be used in a photocatalytic 10 oxygcnalio~fr~o m Lhc watcr conlcnl of mammalian blood. Said pliotocatalytic oxygenator is used for perf'or~ninge xtracorporeal oxygenation of paticnl's blood for various chronic and acute pulmonary disorders and to generate oxygcn either in-vilro or in-vivo in tna~nmalian blood. The photocatalyst disclosed herein along with all other applications associated wilh pliotoca~~~cyasn~ asls o be used effectivciy in the following fields 1 areas: 15 Effluent treatments: Air (rcmoval / oxidation of CO and NOX and water purification organic pollulants (polh~lanl waler from the textile and leather and si~iiilar industries), Stwilizalion of ~ncdical equipmcnt and hospilal iloors and wztlls, Antifogging and sclf clcaning of facatics and window j~anes ill boildil~gs (Illis appliciltion includes thc hydrophillicity properly of pliolocalslysls). BACKGROIIND OF TIIE INVENTION Oxygen in continual supply is essential for human life. (;as exchange with the atrnosplierc accepting oxygcn from the atmospliorc and excreting cnrhodioxide into i t is the lungs chief function. 'The dctails of the slructurc of the lungs can be fount1 in any human 25 ~)hysiological books. 'l'hc lungs consists or alvcoli (or air sacs) measuring to about 70 squarc mctcrs of area. 'l'lic lotal volumc of the lung varies bclwccrl 3.6 to 0.4 liters in adult men ant1 2.5 to 6.9 liters in adult worncn. 'l'lie volurnc of the pulmonary capillary circulation is about 150 mI which is spread over a surface area of' 750 squarc fcct. l'hc hloocl and air are hrouglit together closely by a mnenxbrane ol thickness -1.0 micron rnctcr 30 in alveoli. The diffcrcncc in gas pressure of oxygcn in alvcoli and the blood is rcsponsiblc [or the cxchangc of oxygcn from alvcoli into blood and carbon dioxidfc from blood to alveoli (for exhaling C02 into atmosphere). I-Icmoglohin, the iron-containing pigment of red blood cclls carriers oxygcn from the lungs to the tissues. It is cstilnatcd that the number of dcaths in USA from all lung discasc is csti~natcd approximately at 250,000 (of which 150,000 rclatc to acute, potentially rcvcrsiblc 5 respiratory iailure and 100,000 related to the chronic irreversible respiratory failure). 'The rate of dcath related to chronic pul~no~iarluyn g disease (CI'1,U) has increased by 54%. 1,ung disease also represents one of the major causes of infant mo~lality. I-Iypoxia indicates the situation whcrc tissues arc unahlc lo undergo norrnal oxidative processes becansc of a Failure in the supply or utilization oC oxygen. the causes of hypoxia 10 can be grouped illto Sour categories: I . Ilypoxic hypoxia: Ilypoxic hypoxia is defiued as an inadcquare parlinl ]~rcssurco>f oxygcn (P02) in arterial blood. 'l'his can rcsull Erorn an inadequate PO2 in the inspircd air (such as at altitude), major liypovcntilation (lro~nc entral or pcriferal causes) or from inadequale alveol2u.capillo.y transfer. 15 2. Ancn~ic hypoxia: the oxygen content ol' arterial blood is allnos1 all hound to l~cmoglobin (111)). la thc l~rcscncc of scvcrc ancmia, the oxygen content will thcrcforc fall in proporlion to the reduction in llh conccnt~.atione, ven though the 1'0'2 is nonlial. ' h e nor'rnal compensatory mechanism to restore oxygcn dclivcry is an i ~ i c ~ aisn cc ardiac output, but when this can no longer he sustained lissue 20 hypoxia results. Conditions in which 1-lb is rendered ind'fcctivc in binding oxygcn, such as carbon monoxiclc poisoning, lvoducc a reduction in oxygen carriage similar 10 anemia. 3 (:irculating or slagnant hypoxia: if circulatory failure occurs, even though the oxygcn content of' artc~.ialb lood ~ndyb c adequate, dclivcry to the tissues is not. Initially lissuc oxygenation is ~iraintaincd by increasing the dcg~,cc of oxygcn extraction from the blood, but as tissue pc~.lilsion worscns this hccolncs insurficient and lissuc hypoxia dcvclops. 4. Ilistotoxic hypoxia: this describes where cellular metabolic ])roccsscs arc impaired to prevent oxygcn utilization by thc cclls, even though oxygen delivery to thc tissues is normal. 'l'he best-known cause of histotoxic hypoxia is cyanide poisoning, which inhibits cytochromc oxidese. Oxygen therapies: Photo-catalyst is the substances that regulate light-catalyscd reactions. 'Thcrc have been numerous efforts in the past 40 ycars to achicvc artificial lung function. 5 1JS 4,061,55 discloses a watcr splitting apparatus with grated nickcl oxide as cathodc and photocatalytic N-type semiconductor (Rutile- l'i02) as anode and NaON dissolved watcr as electrolyle. The electrodes arc biased using a pote~itiald eveloped across Solar ccll. On biasing junction is created in anodc/electl.olyte interface. So when light is shine oti the 10 anodc, electron- hole pair is generated with hole migrating towards anode/electrolytc cleclrolyte and electrons move towards cathodc. 't'hc holes present in anode/electrolyt interface reacts with hydroxyl ions prcscnt in the clcctrolytc and after several complcx reactions and products forms oxygen and wntcr. 'The gcncratcd clcctrons move to calliodc under the i~iflue~lcoef biasi~ig voltage and in thc cathodc/clcctrolylc inlerCacc the 15 clcctrons react with tlic watcr to form hydrogc~i and hydroxyl ions (thc process is ralhcr complex). 'Thus hydrogen is evolved in the cathotlc anti oxygen is evolved in anodc using photocalalysis or watcr. US 4,793,910 discloses a pliotoclcctroclic~iiical ccll i~scd Sor 1>liolr>lysis of water to 20 producc 1~12a nd 02 without external bias. 'l'hc cell co~isisot l"l'i02/1't iiiulti-electrode and pn~duces r12 anti 02. The reproducible bipolar Ti02/I't photoelectrodes wcrc fabricated by oxidation (spark at~odization)o S thin 'l'i foil prc-deposited with I'latinutii. Wliilc watcr colncs in colitact with 'l'iO2/1't clcctroispcssivc Analysis of X rays (I.:I:)X). 'l'lic Photocatalyst lias tlie material consists of tin dopd indiu~no xidc (l'l'0an)d titani~un dioxide ('Ti02). 'Thc photo energy required by said photocatalysl is any single or a range of wavclcngths in the spectlum 255 n m - 1 l(lO111n. 25 Otic cmbodimcnt of the prcsctit invention is to provide a mcthotl of preparation oS said phototcuk~lyst. l'hc iixctl~od of preparation of the novcl mixed metal oxidc cavalyst with nano sized grains consists of deposition oS the tnclal oxidcs by I>(! inagnctl.on sprrttcsing tccliniquc on a substrate followcd by annealing. 'l'lle new material (NM) is a thin film consisting of ~xxixed nxctal oxidcs of tilianiurn, tin, inciiurn. Reactive UC Magnetron 30 sputtering is e~ilploycd lo prepare the thin films. A commncrcial sputtering unit is c~nploycd Tor the purpose. The sputtcving unit consists of a growth chamber, rotary and diffusion pumps for cvacuatioti, vacuum ~neasuring gauges and water coolant Seed troughs for the targets and an arc suppression DC Magnetron power supply. The growth cha~nbers hould consist of a inccha~lis~ton rotate the substrates for ulliforcn coatings. The diffusioll pump is supported by the rotary pump in the 1)C magnetron sputtcring unit. Ally slaudard commercial sputtering system can he employed for preparing the mixed metal 5 oxide th'il~ fillns with suitable growth paramctcrs. 'The non-limiting rcprcscntativc growth parameters arc given under the hcad 'sample preparation'. 'The targets uscd arc coinmercially available pure (09.0%) mctallic Titanium and alloy targct of irldiurn and tin (00: 10 by weightoh). Initially, the growth chamber is evacuated to a base pressure of -10- rnilli bar by a cocnbi~lationo f rotary and diffusio~pl umps. 'Then pure argon and oxygc~l 10 gases arc introduced into the glr)wtl, cl~ar~?lx:art specified flow rates such that the growth chamber vacuum is at - 3-4 x 10.' rnilli bar. 111 order to ~nai~ltatih~cslc pressures in the growth chamber, the sputtering systcul should have a throttlc valve. 'Then the Parget is powered by a magnetron power supply (simi1;ir to Advanced 1':ncrgy where there is a provision for arc suppression). 'l'hc thin films are prepared for desired thicltness either 15 by c~nploying a thickness monitor or by noting ihc time of sputtcring. All tlie thin films arc pscparcd at room tcmpcraturc + 300K; however, during sputtering thcrc will bc an inherent incxase in the temperature at the substrate and it should not exceed more than 80°<: ror tllc colnplcw growth of the thin riln~s.'l 'he tcmperaturc of deposition should lie in tllc r;ingc 3OOK to 4.00 I<. 'llle s~~itahlscu hstralcs uscd in thc incthotl arc quarl;., 20 sy~ithctic silicotl dionidc, soda li111c glass, poly-ciu-l?onatcs and poly imidcs and ally suitable polymers, 'The most suitable substrates are quartz ant1 synthetic silicon dioxide. Sarnple nrcnaration 'The substrates employed werc cl~cmically cleaned qualvz platcs and quartz tubes. 'l'hc 25 platcs wclc uscd Sor characterizing the NM tllirl films and the tubes were uscd for the mcasurcmcnt of photocatalytic activity. The dimensions of thc quartz plates wcsc: 38 mm(length) x 09 mm (I>rcadth) x 01 ixim (height) atid quark tube hiid the dimanion : 255 lnln (length) x 10 lnln (innos diameter). 'l'hesc suhstrates were clcancd followillg the standard cleaning mcthods: soap wash, acctonc wash, c h r o ~ ~aicci d was11 ~ollowedh y 30 distilled water clcau up and dried with nitrogen gas. 'lhe elcalled suhstrates wuc loaded into the growth chamber. Initially, tin doped indium oxide (PTO) coatings of desired thicltness were carricd out; then without bre&~ng vacuum, 'Ti02 coatings oC rcquivcd thickness wcrc carried out. 'l'l~e lion-limiting growth 1 process paralneters employed in the process were as follows: 1:ncrgy MIIX l'ower magnetron power Magnetron power .J Nolc: 'l'hese growth pauamctcrs a1.e indicative but not cxclusivc. 'fie coated substriitcs with tlicsc thin films arc anncalctl a1 a tcml~eralurer anging bctwce~i 500°C - 700°(: preferably - 600 I 10°C in atnhicnt air. 'l'hcsc urc Lllc NM tliill films. 10 'I'liese mixed tnetal oxides are characterked for their structural, electrical, optical and photocavalytic properlics. Another ernhodirncnt of the present invention is the a photocatalytic oxygcnator and a lncthod of oxygenation of hlood of ~nan~maliabnold y com)?rising lhc ~iovepl hotocatalysl layer of mixed metal oxides of titanium, indium and tin as a thin film with llano sizct-l grains. The atomic percentage of the constituents in said phoIocat8lytic layer is: I~idiu~inn 5 tlic rangc of about 3.58-4.80; tin in thc raugc of about 0.29-0.32 and 'l'itanium in the rangc of about 0.62-0.72 (as mcasurcd by NIX mcasurcmcnts on the thin films) along with oxygen. The photocatalytic oxygenator co~nprising Lhc novel photocatalyst layer effectively perform the exhocrporedl oxygenation of patien's blood for various chronic and acute pulmonary disorders and gcncrates oxygen either in-vituo or in-vivo of the 10 hlood in mammalian body. 'The novcl photocatalyst of thc present invention is found Lo be more efficient compared with the conventional titanium dioxide pholocalalyst. Thc novcl photocatalyst disclosed hercin along with all other applications associated with photocatalysts can also hc used 15 cfrcclively in Effluent trcatmcnls: Air (removal of CO and NOX and water purification organic pollutants (pollulant water from thc tcxtilc'and icathcr and similar industries), Stcrilizal'ion ol' ~ncdical cquipmncnt and hospitnl floors and walls, Antilhgging and self clca~iing of facades and window panes in buildings (this application includes the l~ydrophillicityp roperty ol pliotocatalysts). 20 ICXAMP1,ES Exnn~ple '1 : Method cmploycd To1 the measurcmcnt of the p11oti)catalytic activity of NM to comparc it 25 with the photocnlalytic activity of tlic normal titaniom dioxide. 'The pl~olocaralytic~ ~ctivily of thcsc thin films (both platcs and tuhcs) is cl~aractcrizcdu sing the principle or' oxidation of organic dyes. Rhoda~~~Ii3 nies the dye chosen for tlic purposc. For tubes, thc actual oxygen (dissolved oxygen) produced hy pliotocalalysis is cvalnatcd hy using an oxyprohe procured liom MIS Ocean optic con~patiy(I JSA). 30 Photocatalvtic activity mcasurcmcnts on ~latcs: Thc coated platcs arc placed in a Petridish and it is filled with 0.002 mole% o l Rhoda~nine 13 solution (10 mg oS Rhodarnine R is dissolved in I litres of pure distilled water). Dcfore the samples arc exposed to IJV light (254 nin and 365 nm), the optical absorption (optical density) of Rhodamiue lled (1.8 ml filled in a quartz cuette) is measured by ;I double heam optical spcctrophotometer (JASCO). When the catalyst is exposed to the IJV light, the optical 5 transmission of lihodaminc Kcd is ~ncasurcd in regular intervals of 30 minutcs. 'The dccrcasc in the optical absorption of IZhoda~ninc lied with time as a result of photocatalytic action (oxidation) is a rncasure ol'photocatalylic activity. ' f i e Photon flux for the phc>tocatalytic activity is measured by Acti~lo~netreyx pctimcnls 10 and by power meters. l'hotocatalvtic activity in Tubes: 'She tubes arc coated with the NM thin film on the outer surface. 180 milli litrc volume of 0.002 Mol% Rhodamine Red solution surrounds the tube and it is in close contact with the NM thin film. A lJV lamp is inserted into the tuhc 15 and the lamp illumi~latesth e light lrom the inner surface into the outer surPacc. 3.0 1111 of Khoda~ninc Red dye is collcctcd in a quartz cucttc periodically (cvcry 30 minutes) with cx]>osure to IIV light and the optical absorption of IZhoda~ninc Red dye is mcasurcd by a doublc hcam sl)cctrophoto~nc>tc(rJ ASCO). IIac~nocompatibilitys tudy I'reliminary evaluation oS tile effects of the photocalalylic oxygenator on hlood have 25 tlcmonslratctl no significanl Sall in 1111, no risc in serum potassiutn or licmalocril, no KI3C hctnolysis or platclct aggregation. We claim: 1. A l'hotocatalyst colnprisitig nlixed metal oxidcs of lilanium, Indium and tin as a thin 5 film with nano sized grains 2. 'l'hc l'hotocatalyst as claimed in claim 1, whcrcin Lllc precerred atomic percentage of constituents are Indium is about 3.58 - 4.80; tin is about 0.29 - 0.32 and Titanium is about 0.62 - 0.72 (as measured hy T:>X measurements on the thin films) along with 10 oxygcn. 3. The l'hotocatalyst as clanned in claim I , whcrein tlic photocatalyst consists or tin doped indium oxide (ITO) and titanium dioxide ('l'iO2) 15 4. 'l'hc Photocatalyst as clanncd in clinrn 1, wherein the photo cncrgy required is any single or a range of wavelengths in the spcctrinn :255 nm - 1100nm. 5. A incthod of tlic pre1)araition of a photoca~alystc onsisting of titanium, intii~nna nd tiri mixed metal oxide thin rilm with nano sizcd grains comprising deposition of the liictill 20 oxidcs by 1)C inagnctron sputtering tcchniyuc on 21 suhstratc Sollowcd hy i~niicali~ig. 6. The method as claimed in claim 6, whcrein the substrate is quark, synthetic silicon dioxidc, soda lirnc glass, poly-carbonates and poly ilnidcs and any suitable polymers. 25 7. ' f i e niclhod as clailiied in clailn 7, wherein the l~rcfcrrcd substrate is quartz and synthetic silicon dioxide. 8. 'She tncthod as clai~ned in claim 6, whel.cin the tc~npcratule of dcposition is in ihc range of 300K lo 400 K. 3 0 9. 'The incthod as claimed in claim 6, whcrcin annealing is performed at a tcmpcraturc ranging between 500°C: - 700°(: 10. 'l'he method as claimed in claim 10, wherein annealing is perCormcd preferably at a tcmpcraturc oC about hOO0C & 10°C. 5 1 1 l i e method a claimed in claim 6, whcrcin thc TIC magnetron spultcring unit cotnpriscs a diiit~sionp ump supported by rotary pump. 12. A photocatalytic oxygenator and a method of oxygenation oC blood ol ~narnrnalialn hotly comprising a pholocatalyst layer comprising inixcd metal oxidcs of titailiurn, 10 Indinm ant1 tin as a thin film with nano s i ~ c dgr ains. 13. 'llie photocatalytic oxygenator as claimed in claim 13, wherein thc prelerred atowic percclitage of constituents are Indium is present in the range of about 3.58-4.80; tin is present in the range of about 0.29-0.32 and 'l'itanium is present in the range of about 15 0.62-0.72 (as mcasurcd by 13DX mneasuremncnts on the thin films) along with oxygcn. 14. 1Jse of thc photocayalyst as claitncd in any of the ahove claims, s~~hslaiititillsyu ch as hcrcin tlcscrihed in thc tlcscl.iption