Novel multifunctional titania–silica–lanthanum phosphate nanocomposite coatings through an all aqueous sol–gel process

Abstract

A novel nanocomposite coating containing titania, silica and lanthanum phosphate prepared through an all aqueous sol-gel route exhibits excellent self-cleaning ability arising from the synergistic effect of the constituents in the nanocomposite. A highly stable titania-silica-lanthanum phosphate nanocomposite sol having particle size in the range of 30-50 nm has been synthesized starting from a titanyl sulphate precursor, which was further used for the development of photocatalytically active composite coatings on glass. The coatings prepared by the dip coating technique as well as the nanocomposite powders are heat treated and characterized further for their morphology and multifunctionality. The nanocomposite containing 1.5 wt% LaPO4 has shown a surface area as high as 138 m(2) g(-1) and a methylene blue degradation efficiency of 94% in two hours of UV exposure. The composite coating has shown very good homogeneity evidenced by transparency as high as 99.5% and low wetting behaviour. The present novel approach for energy conserving, aqueous derived, self-cleaning coatings may be suitable for large scale industrial applications.

Hydrophobic and Metallophobic Surfaces: Highly Stable Non-wetting Inorganic Surfaces Based on Lanthanum Phosphate Nanorods

“…The rods appeared to have organized to form a spike like arrangement over the surface forming a rougher surface. The morphology of the coated surface is complimentary to the benefits obtained by virtue of the restricted H-bond interactions as mentioned earlier and should have contributed partly to the very high water contact angle observed for the coated sample 22 .…”

Optical Properties of Rare‐Earth Doped TiO2 Nanocomposites and Coatings; A Sol‐Gel Strategy towards Multi–functionality

“…The TSL‐0.5Tb coating has shown a dye degradation efficiency of ∼66 % under 2 h visible light exposure compared to ∼ 25 % for undoped titania coating under similar conditions. The advanced water contact angle measured for TSL‐0.5Tb composite coating was ∼70° against ∼83° for the undoped TSL nanocomposite coating . This reduction in the water contact angle value can be attributed to the presence of large agglomerates on the surface of TSL‐0.5Tb coating which should have altered the surface roughness as revealed from SEM image.…”

Temperature assisted acid catalyzed peptization of TiO2; facile sol–gel approach for thermally stable anatase phase

“…Titanium dioxide exists in three different crystallographic forms anatase, rutile and brookite and the anatase phase has been widely exploited for photocatalytic applications. [1][2][3][4] The crystal structure and size of TiO 2 nanoparticles depend largely on the preparation method. 5 Several synthetic methods such as solgel, 6 hydrothermal, 7 solvothermal, 8 sonochemical, 9 co-precipitation, 10 chemical vapour deposition 11 and physical vapour deposition 12 have been widely reported for titanium dioxide.…”