The Photocatalytic Degradation of Vehicle Exhausts by an Fe/N/Co–TiO2 Waterborne Coating under Visible Light

Abstract

Based on the three-dimensional network structure of a polymer and the principle of photocatalysts, a visible-light-responsive and durable photocatalytic coating for the degradation of vehicle exhaust (VE) has been constructed using a waterborne acrylic acid emulsion as the coating substrate; Fe/N/Co–TiO2 nanoparticles (NPs) as photocatalytic components; and water, pigments, and fillers as additives. The visible-light-responsive Fe/N/Co–TiO2 NPs with an average size of 100 nm were prepared by sol-gel method firstly. The co-doping of three elements extended the absorption range of the modified TiO2 nanoparticles to the visible light region, and showed the highest light absorption intensity, which was confirmed by the ultraviolet-visible absorption spectra (UV-Vis). X-ray diffraction (XRD) measurements showed that element doping prevents the transition from anatase to rutile and increases the transition temperature. TiO2 was successfully doped due to the reduction of the chemical binding energy of Ti, as revealed by X-ray photoelectron spectroscopy (XPS). The degradation rates of NOX, CO, and CO2 in VE by Fe/N/Co–TiO2 NPs under visible light were 71.43%, 23.79%, and 21.09%, respectively. In contrast, under the same conditions, the degradation efficiencies of coating for VE decreased slightly. Moreover, the elementary properties of the coating, including pencil hardness, adhesive strength, water resistance, salt, and alkali resistance met the code requirement. The photocatalytic coating exhibited favorable reusability and durability, as shown by the reusability and exposure test.

Impact of Titanium Dioxide (TiO2) Modification on Its Application to Pollution Treatment—A Review

“…Co-doped nanoparticles exhibit higher visible light absorption than single doped TiO 2 due to a synergistic effect between the two dopants, which can efficiently increase the photocatalytic performance [150]. Co-doping can be divided into different metal elements co-doping [151][152][153], metal elements and non-metal elements doping [154][155][156] and different non-metal elements doping [157][158][159]. As shown in Table 2, many researchers have used co-doping method to modify TiO 2 and tested the photocatalytic performance of the materials.…”

RSM-Based Optimization of the Parameters Affecting TiO2-Mediated UV Photocatalysis of Vehicular Emissions in Enclosed Parking Garages

“…With a motive to reduce vehicular pollution, in ambient air, studies have identified the usage of photocatalytic material, i.e., TiO 2 , on the asphalt roads, as significantly efficient [19,20]. It has been reported that when applied on the surface of the roads, TiO 2 can significantly reduce the concentration of several pollutants, viz., organic carbon, NO x , SO 2 , and volatile organic carbons (VOCs) [21][22][23]. To reduce the ambient air pollution, many countries, around the world have also adopted the usage of TiO 2 in the construction of pavements, buildings, windows, etcetera [20,24,25].…”

Assessing the Applicability of Photocatalytic-Concrete Blocks in Reducing the Concentration of Ambient NO2 of Chandigarh, India, Using Box–Behnken Response Surface Design Technique: A Holistic Sustainable Development Approach

“…Among the various oxidation agents, such as TiO 2 , ZnO, Ag 3 PO 4 , CuO, AgI, and Cu 2 S, TiO 2based photocatalysis was reported to be most advantageous because of its high efficiency, easier mobilization on different substrates, lower operational cost, and no damage to environment and living beings [16,17]. erefore, in recent years, scientific community is also working towards exploring the applicability of photocatalysis in reduction of urban-air pollution [18][19][20]. In this regard, several surfaces of the global-urban areas, namely, buildings, roads, and monuments, were reported to be laden with different photocatalysts, and significant reduction in concentration of air pollutants was also reported [19].…”

“…However, in developing nations such as India, where the air quality is generally poor, the studies, emphasizing the use of photocatalysis in reducing the air pollution, are scanty [21,22]. Although few studies estimated the treatment efficiency of TiO 2 for different pollutants, they merely optimized the treatment process using conventional onevariable-at-a-time approach [18][19][20]. Moreover, research gap still exists in identifying the use of response surface methodology in photocatalysis-based reduction of air pollution.…”