Photocatalytic Testing Protocol for N-Doped TiO2 Nanostructured Particles under Visible Light Irradiation Using the Statistical Taguchi Experimental Design

Abstract

The primary objective of this research is to propose and compile a specific protocol for photocatalytic measurements of modified TiO2 particles under visible-light irradiation. Nitrogen-modified titanium dioxide (N-TiO2) powder was synthesized by the sol–gel method and characterized by X-ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman Spectroscopy (micro-Raman), and Ultraviolet–visible Spectroscopy (UV-Vis). Photocatalytic tests were performed on a specially designed photocatalytic batch reactor to test the ability of the powder to degrade hazardous toxic compounds. Via the Taguchi method, nine experiments (L9) were compiled to examine the factors that affect the photocatalytic activity of the nano-sized powder. The N-TiO2 particles were characterized by the dominance of the crystalline anatase phase, exhibiting crystals in the nano-scale. The Taguchi method was designed to control four selected parameters (pollutant selection among azo dyes, amount of catalyst to pollutant, distance of the photocatalytic cell from the radiation source, and time protocol) with three levels/options each. Conclusions were drawn regarding the way each parameter affects the final degradation of the pollutant. The parameter that proved to affect the degradation of the pollutant to a greater extent was the choice of pollutant, followed by the amount of catalyst. The other two factors almost slightly affect the process, with a similar percentage. Taking into account the abovementioned results, a photocatalytic protocol for testing TiO2 nano-powder activity under visible light irradiation is proposed by using a batch, horizontal, rectangular, vis-LED equipped reactor with reflective walls.

Chemically Modified TiO2 Photocatalysts as an Alternative Disinfection Approach for Municipal Wastewater Treatment Plant Effluents

“…The O1s peak can be ascribed to lattice oxygen Ti-O in the TiO 2 state, possessing binding energy equivalent to 530.0 ± 0.1 eV and hydroxides and/or adsorbed water on the surface characterized by a binding energy of 531.7 ± 0.1 eV (Figure 9b) [59]. Figure 10 shows the N1s peak centered at 400.1-400.5 eV, approximately, which can be assigned to N-Ti bonds [60]; and given that the observed line is located above 400 eV, an interstitially doped nitrogen mechanism could be proposed [61,62]. Figure 11a,b shows the Ag3d and AgMNN X-ray-induced Auger spectrum from the Ag@N-TiO 2 sample.…”

Biocompatible PANI-Encapsulated Chemically Modified Nano-TiO2 Particles for Visible-Light Photocatalytic Applications

“…Particularly, RhB (C 28 H 31 CIN 2 O 3 , Penta-Chemicals Unlimited, Prague, Czech Republic) solution (1 L) was prepared using distilled water [32]. RhB has been proven to be very resistant towards TiO 2 compared to other pollutants, such as Brilliant Green and Methylene Blue, indicating that it is stable and thus suitable to be used in photocatalytic trials [36].…”

Synthesis and characterization of TiO2 nanoparticles combined with geraniol and their synergistic antibacterial activity

“…Using natural compounds can greatly enhance the inherent physical and chemical properties of NPs [30,31]. For instance, TiO 2 has been used as an antimicrobial additive in polyamide 12 powder, and nitrogen-doped titanium dioxide nanoparticles have demonstrated photoinduced antimicrobial properties under visible-light irradiation [32,33] The small size, high surface energy, and strong hydrophilicity for surface hydroxylation may increase TiO 2 NPs compatibility with polymer materials [34,35]. Incorporating inorganic NPs into organic polymeric nanocomposites is a promising strategy to enhance their antimicrobial properties [36][37][38].…”