title: Titania nanowires as substrates for sensing and photocatalysis of common textile industry effluents.
abstract: Sensing and photocatalysis of textile industry effluents such as dyes using mesoporous anatase titania nanowires are discussed here. Spectroscopic investigations show that the titania nanowires preferentially sense cationic (e.g. Methylene Blue, Rhodamine B) over anionic (e.g. Orange G, Remazol Brilliant Blue R) dyes. The adsorbed dye concentration on titania nanowires increased with increase in nanowire dimensions and dye solution pH. Electrochemical sensing directly corroborated spectroscopic findings. Electrochemical detection sensitivity for Methylene Blue increased by more than two times in magnitude with tripling of nanowire average length. Photodegradation of Methylene Blue using titania nanowires is also more efficient than the commercial P25-TiO(2) nanopowders. Keeping illumination protocol and observation times constant, the Methylene Blue concentration in solution decreased by only 50% in case of P25-TiO(2) nanoparticles compared to a 100% decrease for titania nanowires. Photodegradation was also found to be function of exposure times and dye solution pH. Excellent sensing ability and photocatalytic activity of the titania nanowires is attributed to increased effective reaction area of the controlled nanostructured morphology.
authors.affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Malleshwaram, Bangalore 560012, Karnataka, India. aninda_jb@sscu.iisc.ernet.in
authors.forename: Soumit S
authors.initials: SS
authors.lastname: Mandal
authors.forename: Aninda J
authors.initials: AJ
authors.lastname: Bhattacharyya
mesh_terms: D000327:Adsorption; D004396:Coloring Agents; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis; D053770:Nanowires / Q000737:chemistry*; D055668:Photochemical Processes; D010782:Photolysis; D013783:Textile Industry; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium