Hydrophilic/Hydrophobic Silane Grafting on TiO2 Nanoparticles: Photocatalytic Paint for Atmospheric Cleaning

Abstract

In this study, anatase titania was utilized to prepare a durable photocatalytic paint with substantially enhanced photoactivity towards NO oxidation. Consequently, to alleviate the choking effect of photocatalytic paint and incorporate self-cleaning properties, the parent anatase titania was modified with Al(OH)3 and a number of organosilane (tetraethyl orthosilicate, propyltrimethoxysilane, triethoxy(octadecyl)silane, and trimethylchlorosilane) coatings. A facile hydrolysis approach in ethanol was employed to coat the parent titania. To facilitate uniform dispersion in photocatalytic paint and strong bonding with the prevailing organic matrix, it is necessary to avail both hydrophobic and hydrophilic regions on the titania surface. Therefore, during the preparation of modified titania, the weight proportion of the total weight of alkyl silane and trimethylchlorosilane was adjusted to a ratio of 1:1. As the parent titania has few hydrophilic portions on the surface, tetraethyl orthosilicate was coated with an organic silane having an extended alkyl group as a hydrophobic group and tetraethyl orthosilicate as a hydrophilic group. When these two silane mixtures are hydrolyzed simultaneously and coated on the surface of parent titania, a portion containing a large amount of tetraethyl orthosilicate becomes hydrophilic, and a part containing an alkyl silane becomes hydrophobic. The surface morphology and the modified titania’s optical attributes were assessed using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), UV-Vis diffuse reflectance spectroscopy (DRS), and electrochemical impedance spectroscopy (EIS) analysis. Based on the advanced characterizations, the NO removal mechanism of the modified titania is reported. The modified titania coated at 20 wt.% on the ceramic substrate was found to remove ~18% of NO under one h of UV irradiation. An extensive UV durability test was also carried out, whereby the coated surface with modified titania was exposed to 350 W/m2 of UV irradiance for 2 weeks. The results indicated that the coated surface appeared to preserve the self-cleaning property even after oil spraying. Hence, facile hydrolysis of multiple organosilane in ethanol could be a viable approach to design the coating on anatase titania for the fabrication of durable photoactive paint.

Flexible Nano-TiO2 Sheets Exhibiting Excellent Photocatalytic and Photovoltaic Properties by Controlled Silane Functionalization─Exploring the New Prospects of Wastewater Treatment and Flexible DSSCs

“…To the best of our knowledge, our work reports the best performing silane-modified TiO 2 flexible photocatalyst sheet that decomposes the MB dye to more than 95% extent within the first 10 min of irradiation, and to more than 99% within less than an hour of irradiation, which is a significantly greater improvement over bare TiO 2 , which is capable of decomposing the dye to a maximum of 68% ( vide infra ). In a nutshell, we demonstrate that the prepared nano-TiO 2 sheets (M-TiO 2 ), compared to bare TiO 2 , showcase superior photocatalytic activity and reasonably high photovoltaic properties at room temperature and show far better efficiency than that of other similar reported synthesis routes …”

“…In a nutshell, we demonstrate that the prepared nano-TiO 2 sheets (M-TiO 2 ), compared to bare TiO 2 , showcase superior photocatalytic activity and reasonably high photovoltaic properties at room temperature and show far better efficiency than that of other similar reported synthesis routes. 31 ■ EXPERIMENTAL SECTION A detailed experimental section is provided in Supporting Information. 46−48 Preparation of TiO 2 Nanoparticles.…”

“…Other well-known photocatalysts like ZnO/ZrO 2 nanofluids were also prepared using similar surface modification strategies. A multitude of articles − report the synthesis of silane-modified TiO 2 through various routes, its rheological properties, its adhesive nature on various substrates, and so forth. However, of these articles, only a handful discuss the possibility of using silane-modified TiO 2 in photocatalysis.…”

Multiclass Level-Set Segmentation of Rust and Coating Damages in Images of Metal Structures

“…It is necessary to consider technological heredity to ensure the product’s functioning throughout its life cycle when preparing the surface for coating [ 40 , 41 , 42 ]. Technologies for applying environmentally friendly hydrophobic, photocatalytic, and antimicrobial coatings that do not cause environmental pollution are being developed [ 43 , 44 , 45 ]. Operational methods include surface cleaning and repair of damaged areas of coatings.…”

Introduction of Water Treatment in Slot‐Die Coated Organic Solar Cells to Improve Device Performance and Stability

“…Besides, water does not dry quickly and remain in the film after completely drying compared with organic solvents because of the proper vapor pressure (23.8 Torr at 25 °C) and boiling point (100 °C) in air, so there are many cases where water is used such as water‐based paint or dye. [ 12 ] Therefore, it is very interesting to use water as a method for morphology control in OSCs by utilizing the inherent properties of water, which is very different from the organic solvents commonly used as the active solvent. In order to further expand the novel processing method of OSCs and their applications, new approaches using water and the vortex effect for the mass production of OSCs are needed to manufacture devices with high efficiency and long‐term stability.…”