Surface techniques such as XRF, DRS, TEM, contact angle (CA), XRD and XPS were applied to relate the microstructure of the TiO 2 coatings with the destruction of Escherichia coli taken as a probe. our device can produce free radicals in water through the loss of kineticenergy.Inameta-stablestate,thefreeradicalsarerecombined into water molecules or trapped in water molecules3638. By XPS evidence is presented for the Ti 4+/Ti 3+ related redox catalysis and the details of the C and O-functionalities. Case 2, the KE of the emitted electrons increases due to the repulsive forces between the charged surface and emitted electrons. Case 1, the emitted electrons have a reduced KE by a few tens of eV Identification remains possible. A further proof of self-cleaning was the ability by the polyester-TiO 2 samples to inactivate again bacterial charge at the end of an inactivation cycle. Auger (and XPS) peaks shift to higher KE (lower BE). Pyrolysis of azomethane molecules (CH3N2CH3) above 1100 K is frequently used as a means to generate methyl. The interaction of methyl radical with Cu(1 1 1) has been studied in our previous work 13,14. Standard alumina The 0 1s spectra of the unreacted alumina shows a small asymmetry on the high-binding-energy side of the peak, which is due to some surface -OH groups on the alumina. As a result, the trapped radicals on the MWNTs surface act as initiators for graft polymerization. The surface elemental concentrations obtained by XPS, for samples and standards, are listed in Table 1. The hydroxyl radicals can be immobilized on the MWNT surface and this produces trapped radicals on the surface of the MWNTs. Evidence for the photocatalyst self-cleaning was found by XPS due to the lack of accumulation of bacterial residues on the polyester-TiO 2. Methyl radical is an essential hydrocarbon species and there are extensive interests in its chemistry on transition metal surfaces 112. The irradiation of water produces hydrogen atoms, solvated electrons, hydroxyl radicals, H 2, H 2 O 2, H 3 O + and OH. After 30 min RF-plasma pretreatment of the polyester samples, the fastest bacterial inactivation was observed concomitant with (a) the largest ratio of surface oxidized to the reduced functionalities as determined by XPS, (b) a strong sample optical absorption as seen by DRS and (c) the highest concentration surface OH-radicals monitoring the fluorescence of the hydroxy-terephthalic acid. Evidence presented for the RF pretreatment of polyester enhances the TiO 2 coating generation of oxidative species/radicals under a low level actinic light irradiation. The compound peak characteristic for O(1s) XPS spectrum deconvoluted using Voigt fitting function (Figure 3(c)) revealed 2 peaks at a binding energy of 529.5 and 531.1 eV.
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