Selective adsorption and photocatalysis of low-temperature base-modified anatase nanocrystals

Anatase titania photocatalysts with positive (TSC60) and negative (TAH60) surface charge were synthesized by extraction with Na2CO3 and NH4OH, respectively, from an acid stabilized sol at low temperature. XRD, TEM, N2 adsorption and ζ –potential were conducted and revealed that the low-temperature synthesized catalysts differ mainly in their surface charge. These catalysts exhibited opposing preferential adsorption and fully selective photocatalysis of methylene blue (MB) and methyl orange (MO) dyes from their aqueous mixture. The preferential adsorption behaviour toward MB and MO was attributed to the catalyst's surface charge whereas the selective photocatalysis was explained by a combined effect of surface charge and crystallinity. On the other hand, the calcined catalysts showed considerable reduction in their dye adsorption capacity and loss of their selective dye degradation. The reduction in surface charge and increase in crystallinity after calcination were found to be responsible for these observations. Degussa P25 was also tested and compared with synthesized catalysts with regard to dye adsorption and photocatalysis. A mechanism for the selective dye positioning on TSC60 and TAH60 coated FTO/ITO plate is also proposed.

[1]  S. Sampath,et al.  Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes. , 2011, Journal of colloid and interface science.

[2]  C. Chia,et al.  Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution. , 2011, Bioresource technology.

[3]  Weiqi Wang,et al.  Adsorption characteristics of methylene blue onto low cost biomass material lotus leaf , 2011 .

[4]  Y. Ide,et al.  Molecular recognitive photocatalytic decomposition on mesoporous silica coated TiO2 particle , 2011 .

[5]  Mietek Jaroniec,et al.  Tunable photocatalytic selectivity of hollow TiO2 microspheres composed of anatase polyhedra with exposed {001} facets. , 2010, Journal of the American Chemical Society.

[6]  J. Moulijn,et al.  Improved performance of TiO2 in the selective photo-catalytic oxidation of cyclohexane by increasing the rate of desorption through surface silylation , 2010 .

[7]  B. Fabry,et al.  Size-selective separation of macromolecules by nanochannel titania membrane with self-cleaning (declogging) ability. , 2010, Journal of the American Chemical Society.

[8]  Katherine E. Redmond,et al.  The Effect of Ionic Charge on the Adsorption of Organic Dyes onto Titanate Nanotubes , 2010 .

[9]  Yaron Paz,et al.  Preferential photodegradation of contaminants by molecular imprinting on titanium dioxide , 2010 .

[10]  J. Moulijn,et al.  Cyclohexane selective photocatalytic oxidation by anatase TiO2: influence of particle size and crystallinity. , 2010, Physical chemistry chemical physics : PCCP.

[11]  Y. Ide,et al.  Molecular recognitive photocatalysis driven by the selective adsorption on layered titanates. , 2010, Journal of the American Chemical Society.

[12]  Nam-Gyu Park,et al.  Selective positioning of organic dyes in a mesoporous inorganic oxide film. , 2009, Nature materials.

[13]  Xiantao Shen,et al.  Selective photocatalysis on molecular imprinted TiO2 thin films prepared via an improved liquid phase deposition method , 2009 .

[14]  Xiantao Shen,et al.  Inorganic molecular imprinted titanium dioxide photocatalyst: synthesis, characterization and its application for efficient and selective degradation of phthalate esters , 2009 .

[15]  Yasuhiro Shiraishi,et al.  Effect of substrate polarity on photocatalytic activity of titanium dioxide particles embedded in mesoporous silica , 2009 .

[16]  J. Chovelon,et al.  Eco-friendly TiO2–AC Photocatalyst for the Selective Photooxidation of 4-Chlorophenol , 2009 .

[17]  J. Macák,et al.  Magnetically guided titania nanotubes for site-selective photocatalysis and drug release. , 2009, Angewandte Chemie.

[18]  W. S. Tung,et al.  Photocatalytic self-cleaning keratins: A feasibility study. , 2009, Acta biomaterialia.

[19]  W. S. Tung,et al.  Self-Cleaning Fibers via Nanotechnology - A Virtual Reality , 2008, 2008 8th IEEE Conference on Nanotechnology.

[20]  T. Rajh,et al.  Selective Photocatalytic Decomposition of Nitrobenzene Using Surface Modified TiO2 Nanoparticles , 2008 .

[21]  Xiantao Shen,et al.  Enhanced photocatalytic degradation and selective removal of nitrophenols by using surface molecular imprinted titania. , 2008, Environmental science & technology.

[22]  G. Palmisano,et al.  Nanostructured rutile TiO2 for selective photocatalytic oxidation of aromatic alcohols to aldehydes in water. , 2008, Journal of the American Chemical Society.

[23]  J. Kallas,et al.  Selective photocatalytic oxidation of steroid estrogens in presence of saccharose and ethanol as co-pollutants , 2007 .

[24]  Xiantao Shen,et al.  Synthesis of molecular imprinted polymer coated photocatalysts with high selectivity. , 2007, Chemical communications.

[25]  Yasuhiro Shiraishi,et al.  Adsorption-driven photocatalytic activity of mesoporous titanium dioxide. , 2005, Journal of the American Chemical Society.

[26]  K. Inumaru,et al.  Direct nanocomposite of crystalline TiO2 particles and mesoporous silica as a molecular selective and highly active photocatalyst. , 2005, Chemical communications.

[27]  J. Weber,et al.  Selective solar photodegradation of organopollutant mixtures in water , 2004 .

[28]  Shoji Yamanaka,et al.  Enhanced photocatalytic decomposition of 4-nonylphenol by surface-organografted TiO2: a combination of molecular selective adsorption and photocatalysis , 2004 .

[29]  E. Forgács,et al.  Removal of synthetic dyes from wastewaters: a review. , 2004, Environment international.

[30]  J. Weber,et al.  First approach of the selective treatment of water by heterogeneous photocatalysis , 2004 .

[31]  Jimmy C. Yu.  Effects of acidic and basic hydrolysis catalysts on the photocatalytic activity and microstructures of bimodal mesoporous titania , 2003 .

[32]  C. Lamberti,et al.  Enhancement of the ETS-10 titanosilicate activity in the shape-selective photocatalytic degradation of large aromatic molecules by controlled defect production. , 2003, Journal of the American Chemical Society.

[33]  M. Shirai,et al.  Application of Titania Nanotubes to a Dye-sensitized Solar Cell , 2002 .

[34]  B. Prélot,et al.  Electrochemical properties of solids at the aqueous-solid interface and heterogeneity of surface , 2002 .

[35]  H. Haick,et al.  Selective photocatalysis by means of molecular recognition. , 2001, Journal of the American Chemical Society.

[36]  P. Calza,et al.  Shape-selective photocatalytic transformation of phenols in an aqueous medium. , 2001, Chemical communications.

[37]  B. Ohtani,et al.  Photocatalytic Activity of Amorphous−Anatase Mixture of Titanium(IV) Oxide Particles Suspended in Aqueous Solutions , 1997 .

[38]  Andrew Mills,et al.  WATER-PURIFICATION BY SEMICONDUCTOR PHOTOCATALYSIS , 1993 .

[39]  K. Sing.  Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984) , 1985 .

[40]  G. A. Parks.  Aqueous Surface Chemistry of Oxides and Complex Oxide Minerals: Isoelectric Point and Zero Point of Charge , 1967 .