Photocatalytic properties of TiO2-functionalized tiles: influence of ceramic substrate

Abstract

To confer self-cleaning properties to ceramic tiles through photocatalytic phenomena, TiO 2 is deposited as thin films on their surface. However, photocatalytic properties could be strongly influenced by physico-chemical characteristics of the ceramic support. For this reason, this investigation was aimed to study the influence of porosimetric characteristics of different ceramic tiles on adsorption and photocatalytic activity induced by deposited TiO 2 film in the presence of UV light. Experimental data in dark conditions showed that the porosity of the support strongly influenced the adsorption phenomenon of methylene blue (MB). Porosimetric characteristic of samples were tested by Hg intrusion. Higher porosity of the ceramic substrate increased the amount of MB adsorbed. On the contrary, photocatalytic tests have evidenced that a lower porosity of the support determined a higher MB discoloration rate. These results could be explained considering the MB internal diffusion phenomena limit the overall activity inside the porosimetric structure of functionalized tiles.

Solar‐Driven Continuous CO2 Reduction to CO and CH4 using Heterogeneous Photothermal Catalysts: Recent Progress and Remaining Challenges

“…Various approaches to continuous photoreactor design have been proposed, including optical fiber, double-skin sheet, fluidized bed, and annular reactors. [173][174][175][176] The transparent part should be designed to allow for homogeneous irradiation of the catalyst bed and its material should have minimal absorption in the solar spectrum to minimize energy losses. Reflection losses from the surface of the reactor should be minimized, for example, by applying anti-reflective coatings or surface treatments.…”

Optimising processing conditions for the functionalisation of photocatalytic glazes by ZnO nanoparticle deposition

“…Meseguer et al (15) demonstrated the photocatalytic capacity of ceramic glazes as a new functionality of ceramic tiles with applications in construction (such as flooring and wall covering) and in the field (such as air purification and water cleaning). Photocatalytic ceramic tiles are typically prepared by coating the ceramic tile with anatase TiO 2 using various deposition techniques, such as spray deposition (16)(17)(18)(19), screen printing (20,21) and sol-gel methods (22)(23)(24). However, several critical aspects must be considered to obtain suitable TiO 2 -containing ceramic materials: firing temperature and adhesion of the TiO 2 film/particles to the substrate (21,25,26).…”

Development of Photocatalytic Coatings by Thermal Hydrolysis of TiCl4 on Ceramic Roofing Tiles Made from Ferroalumina and Evaluation of De-Pollution Properties

“…Moreover, Ducman et al [2] studied the formation of photocatalytic coatings on ceramics building products (tiles, glass and roofing tiles) by spraying of a TiO 2 isopropanol suspension. Another scientific work related to TiO 2 functional tiles was performed by Vaiano et al [24] who examined the influence of the substrates porosity on the photocatalytic activity of coated ceramic tiles. However, no work was found, up to now, in the literature regarding the application of Chemical Vapour Deposition (CVD) for the production of coated heavy clay ceramics.…”