Commercial P25 TiO2 Research Articles

Metal-free g-C3N4 photocatalysis of organic micropollutants in urban wastewater under visible light

Heterogeneous photocatalysis under visible light was employed for the degradation of organic micropollutants (MPs) found in the biologically treated effluents of an urban wastewater treatment plant (UWWTP). The irradiation source consisted in 4 light emitting diodes (LEDs) with a nominal power of 400–500 W m–2 at 417 nm. Metal-free exfoliated graphitic carbon nitride (gCNT), which was synthetized through a simple thermal treatment using dicyandiamide as precursor, was employed as photocatalyst. The gCNT material was characterized using different techniques: N2 adsorption isotherms at 77 K, electron microscopy (scanning and transmission) and diffuse reflectance UV–Vis. The photocatalytic performance of the material was compared to the commercial TiO2-P25, confirming that gCNT led to a remarkable higher removal efficiency of the target MPs. Most of these MPs were removed in less than 10 min to levels below the limit of quantification (carbamazepine > isoproturon > clopidogrel > diclofenac > atenolol > bezafibrate > tramadol > venlafaxine > fluoxetine). Indirect photolysis, resulting from the secondary reactive oxidants generated during the irradiation of the aqueous matrix components, was found to partially contribute for the elimination of the occurring MPs. In addition, the gCNT photocatalyst was immobilized on glass rings for use under continuous mode operation, a minimum residence time of 25 min being required to attain significant removal efficiencies. Phytotoxicity experiments showed that heterogeneous photocatalysis did not enhance the toxicity of the wastewaters.

Synthesis of uniform ordered mesoporous TiO2 microspheres with controllable phase junctions for efficient solar water splitting.

As a benchmark photocatalyst, commercial P25-TiO2 has been widely used for various photocatalytic applications. However, the low surface area and poorly porous structure greatly limit its performance. Herein, uniform ordered mesoporous TiO2 microspheres (denoted as Meso-TiO2-X; X represents the rutile percentage in the resultant microspheres) with controllable anatase/rutile phase junctions and radially oriented mesochannels are synthesized by a coordination-mediated self-assembly approach. The anatase/rutile ratio in the resultant microspheres can be facilely adjusted as desired (rutile percentage: 0-100) by changing the concentration of hydrochloric acid. As a typical one, the as-prepared Meso-TiO2-25 microspheres have a similar anatase/rutile ratio to commercial P25. But the surface area (78.6 m2 g-1) and pore volume (0.39 cm3 g-1) of the resultant microspheres are larger than those of commercial P25. When used as the photocatalyst for H2 generation, the Meso-TiO2-25 delivers high solar-driven H2 evolution rates under air mass 1.5 global (AM 1.5 G) and visible-light (λ > 400 nm), respectively, which are significantly larger than those of commercial P25. This coordination-mediated self-assembly method paves a new way toward the design and synthesis of high performance mesoporous photocatalysts.

Biodegradation of cotton fabric impregnated with TiO2 nanoparticles

Commercial P25 TiO2 nanoparticles are widely exploited as an efficient photocatalyst. In the textile domain, these nanoparticles are used for the production of self-cleaning, highly UV protective textiles, with an antimicrobial activity. The disposed textile products may end up in a landfill where they are subjected to the biodegradation process. Considering the importance of the later, this study discusses the biodegradation behaviour of cotton fabric impregnated with commercial P25 TiO2 nanoparticles. Photocatalytic activity of TiO2 nanoparticles immobilized on cotton fabric was proved by the photodegradation of dyes C.I. Acid Orange 7 and methylene blue in aqueous solution. Biodegradation of fabrics was assessed by soil burial test in periods of 3, 9 and 18 days. Chemical and morphological changes induced by biodegradation were analyzed by FTIR, SEM and EDS. A colour of the samples gradually changed from white to yellow/brown due to rotting. SEM analysis revealed a severe destruction of the control and impregnated cotton fibres after 18 days of soil burial which was in line with visual appearance of completely damaged fabrics. The results confirmed that biodegradation behaviour of both the control and impregnated sample was equivalent, indicating that P25 TiO2 nanoparticles did not inhibit the biodegradation process of cellulose.

Optimizing one-dimensional TiO2 for photocatalytic hydrogen production from a water-ethanol mixture and other electron donors

This work is focused on synthesizing and employing one-dimensional (1D) titanium dioxide (TiO2) for hydrogen (H2) production. Based on using electron donors (EDs) (ethanol, methanol, fomic acid and 1,2,3 propanetriol), the increased H2 production, when compared to P25 TiO2 nanoparticles, was due to the large specific surface area (SSA) and enhanced electron mobility of 1D TiO2. The impact of the 1D TiO2 synthesis reaction conditions (temperature, NaOH concentration and the TiO2 precursor concentration) on the photocatalytic H2 production rate was evaluated using a 3-factor 3-level Box Behnken design (BBD). The BBD model demonstrated that the temperature and the NaOH concentration significantly affected the 1D TiO2 phase structure, crystal size, SSA, bandgap and the photocatalytic H2 production rate. The phase structure and crystal size of 1D TiO2 were key factors affecting the H2 production rate. 1D TiO2 containing an anatase phase with a mean crystal size of 20.1 ± 0.2 nm was synthesized at 126 °C, 15 M NaOH and 49 g L−1 TiO2. The maximum H2 production rate of 475 ± 12 μmol·h−1 (quantum efficiency (ε) = 20.2 ± 0.5%) for the 1D TiO2 sample was significantly enhanced when compared to commercial TiO2 P25. The H2 production rate for the optimized 1D TiO2 was significantly enhanced by decorating the structure with Pt and Au. Hydrothermal synthesized of 1D TiO2 provided an efficient and low cost method for producing H2 from ethanol, methanol, fomic acid and 1,2,3 propanetriol.

Visible active reduced graphene oxide loaded titania for photodecomposition of ciprofloxacin and its antibacterial activity

The reduced Graphene Oxide based titanium dioxide (rGO-TiO2) nanocomposite was synthesized by a simple hydrothermal preparation and characterized by X-ray Diffraction Analysis (XRD), UV–vis absorption spectroscopy (UV), Fourier Transform Infrared spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The XRD pattern of rGO-TiO2 indicates the presence of anatase TiO2 and average crystalline size of particles is 32 nm. The optical band gaps of TiO2, GO and rGO-TiO2 nanocomposite are 3.24 eV, 4.3 eV and 2.7 eV respectively. Comparison of efficiencies of three catalysts shows that ciprofloxacin degrades at a faster rate under visible light irradiation in the presence of rGO-TiO2 at 60 min than in presence of pure TiO2 and commercial TiO2-P25. Higher photocatalytic decomposition efficiency of rGO-TiO2 is explained by its reduced electron-hole recombination and visible light activity. The kinetics of photodecomposition reaction was analyzed. Antibacterial activity analysis of rGO-TiO2 nanoparticles reveals that it is more active against S. aureus than E. coli.

Nontopological transformation of hierarchical TiO2 by self-regulated etching and capping roles of F− for photocatalytic H2 evolution

In the past decade, crystal facet engineering of TiO2 though various controllable strategies has attracted a lot of attention due to its strong facet dependent photoactivities. In this work, we report on nontopological transformation of titanium oxydifluoride (TiOF2) to hierarchical TiO2 structures by hydrothermal tailoring. The fluorine-containing species in TiOF2 crystal perform the roles as either an etching agent or a capping agent, which can conveniently modulate morphologies and facets of TiO2 crystals via dissolution or oriented collapse under hydrothermal condition. The Wulff construction and different surface energies of shape and facet lead to the controlled formation of hierarchical TiO2, respectively with (1 0 1) faceted nanowalls, (0 0 1) and (1 1 1) faceted nanosheets, or their multi-facets. All TiO2 with single exposed facet exhibit higher photocatalytic H2 evolution performance than the commercial P25 TiO2. Moreover, the (1 0 1) faceted nanowalls demonstrate superior photocatalytic H2 evolution to (1 1 1) and (0 0 1) faceted TiO2 nanosheets in presence of hole scavenger (methanol) due to favoured hole transfer at (1 0 1) facet/methanol interface. This work presents novel methodology for shape and facet control of TiO2 towards solar to fuel conversion.

Highly Selective Photocatalytic Reduction of o-Dinitrobenzene to o-Phenylenediamine over Non-Metal-Doped TiO2 under Simulated Solar Light Irradiation

Photocatalytic reduction and hydrogenation reaction of o-dinitrobenzene in the presence of oxalic acid over anatase-brookite biphasic TiO2 and non-metal-doped anatase-brookite biphasic TiO2 photocatalysts under solar simulated light was investigated. Compared with commercial P25 TiO2, the prepared un-doped and doped anatase-brookite biphasic TiO2 exhibited a high selectivity towards the formation of o-nitroaniline (85.5%) and o-phenylenediamine ~97%, respectively. The doped anatase-brookite biphasic TiO2 has promoted photocatalytic reduction of the two-nitro groups of o-dinitrobenzene to the corresponding o-phenylenediamine with very high yield ~97%. Electron paramagnetic resonance analysis, Transient Absorption Spectroscopy (TAS) and Photoluminescence analysis (PL) were performed to determine the distribution of defects and the fluorescence lifetime of the charge carriers for un-doped and doped photocatalysts. The superiority of the doped TiO2 photocatalysts is accredited to the creation of new dopants (C, N, and S) as hole traps, the formation of long-lived Ti3+ defects which leads to an increase in the fluorescence lifetime of the formed charge carriers. The schematic diagram of the photocatalytic reduction of o-dinitrobenzene using the doped TiO2 under solar light was also illustrated in detail.

Sunlight photoactivity of rice husks-derived biogenic silica

Carbon-containing SiO2-based photocatalysts were prepared by the solvothermal treatment of rice husk as biogenic precursor in the presence and absence of TiO2 and used for the photocatalytic degradation of rhodamine-B under simulated solar light. Data showed that the prepared catalysts are mainly composed of biogenic silica and displayed mesoporous character with surface areas ranging from 65 to 174 m2 g-1. The obtained materials showed photocatalytic activity comparable to that of commercial TiO2-P25 powders for the degradation of rhodamine-B under sunlight. The calcination at 350 °C improved the photocatalytic activity of the biogenic precursor by three times in the absence of TiO2. At converse, calcination of sample SiO2-TiO2 decreased the photoactivity due to the appearance of non-photoactive TiSiO4 crystalline phases in the catalyst, as inferred by XRD and XPS. A reaction mechanism for rhodamine-B degradation excluding the deethylation pathway has been proposed, based on the evolution of the absorbance spectra of rhodamine-B upon the photocatalytic tests.

BixTiyOz-Fe multiphase systems with excellent photocatalytic performance in the visible

New photocatalysts based on bismuth titanates doped with iron with outstanding visible photocatalytic activity were prepared by a facile hydrothermal method followed by incipient wetness impregnation. The starting material was composed by three phases; majority of Bi20TiO32 closely interconnected to Bi4Ti3O12 and amorphous TiO2. Fe doping increased the already very high visible activity of the original material. The high visible activity showed by these materials could be ascribed to a combination of several features; i.e. low band gap energy value (as low as 1.78 eV), a structure allowing a good separation path for visible photogenerated electron-holes pairs and a relatively high surface area. Fe doping could be acting as bonding paths for the bismuth titanates phases, and the amount of Fe on the surface was found to be a crucial parameter on the photocatalytic activity of the materials. Visible activity of the best photocatalyst was superior to UV-Activity of commercial TiO2 P25 used as reference in same experimental conditions.

Confined Preparation of N-doped Commercial P25 TiO2 Photocatalysts with Fast Charge Separation by Argon-diluted Nitrogen Plasma Treatment

Confined Preparation of N-doped Commercial P25 TiO2 Photocatalysts with Fast Charge Separation by Argon-diluted Nitrogen Plasma Treatment

Visible-Light-Driven Photocatalytic N-Doped TiO2 for Degradation of Bisphenol A (BPA) and Reactive Black 5 (RB5) Dye

Bisphenol A (BPA) and reactive black 5 (RB5) dye are among the most persistent and non-biodegradable contaminants in water which require an urgent need for the development of effective removal method. The ubiquitous existence of both contaminants could interfere with the human health and aquatic environmental balance. Photocatalytic process as one of advanced oxidation processes (AOPs) has shown high performance for degradation of organic compounds to the harmless materials under sensible condition. Therefore, this study aims to develop a visible-light-driven photocatalyst that can efficiently degrade BPA and RB5 present in household water. N-doped TiO2 were successfully synthesized via simple and direct sol–gel method. The prepared TiO2 nanoparticles were characterized by field emission scanning microscope (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Brunauere Emmette Teller (BET) analysis. The incorporation of nitrogen in TiO2 lattice exhibited excellent optical responses to visible region as revealed by UV–Vis–NIR spectroscopy absorption capability at 400–600 nm. The photocatalytic activity of the N-doped TiO2 nanoparticles was measured by photocatalytic degradation of BPA and RB5 in an aqueous solution under visible-light irradiations. Degradation of BPA and RB5 was 91.3% and 89.1%, respectively after 360 min illumination. The degradation of BPA and RB5 by N-doped TiO2 was increased up to 89.8% and 88.4%, respectively under visible-light irradiation as compared to commercial TiO2 P25. This finding clearly shows that N-doped TiO2 exhibits excellent photocatalytic degradation of BPA and RB5 under visible irradiation, hence have a promising potential in removing various recalcitrant contaminants for water treatment to fulfill the public need to consume clean water.

Black TiO2 nanotube arrays decorated with Ag nanoparticles for enhanced visible-light photocatalytic oxidation of salicylic acid

Novel forms of black TiO2 nanotubes-based photocatalysts for water purification were prepared. Two features were combined: decoration of TiO2 nanotube arrays with Ag nanoparticles (sample TiO2-NT's@Ag) and further hydrogenation of this material (TiO2-NT's@Ag-HA). Obtained photocatalysts show high efficiency for degradation of salicylic acid, a typical water-borne pollutant. The photocatalysts considerably exceed the photocatalytic properties of TiO2 nanotubes and commercial TiO2 P25 taken as a reference for modeling of the photocatalytic process. The comparison of photocatalytic activities between novel photocatalyst was based on a numerical approach supported by the complex kinetic model. This model allowed a separate study of different contributions on overall degradation rate. The contributions include: salicylic acid photolysis, photocatalysis in UVB, UVA and in the visible part of applied simulated solar irradiation. The superior photocatalytic performance of the photocatalyst TiO2-NT's@Ag-HA, particularly under visible irradiation, was explained by the combined effect of a local surface plasmon resonance (LSPR) due to Ag nanoparticles and creation of additional energy levels in band-gap of TiO2 due to Ti3+ states at nanotube surfaces. The presence of Ag also positively influence charge separation of created electron-holes pairs. The synergy of several effects was quantified by a complex kinetic model through the factor of synergy, fSyn. Stability testing indicated that the catalysts were stable for at least 20 h. The novel design of catalysts, attached on Ti foils, presents a solid base for the development of more efficient photocatalytic reactors for large-scale with a long-term activity.

Simultaneous Control over Lattice Doping and Nanocluster Modification of a Hybrid CuOx/TiO2 Photocatalyst during Flame Synthesis for Enhancing Hydrogen Evolution

Noble metal‐free hybrid photocatalysts have recently been extensively studied for their applications in the environment and energy field. However, rational design over these photocatalysts is still a challenging task because the detailed mechanism of multi‐component catalysts is not well understood yet. Here, we highlight a state‐of‐the‐art approach, one‐step flame spray pyrolysis (FSP), for preparing high‐efficiency hybrid CuOx/TiO2 photocatalysts, where simultaneous control over lattice doping and nanocluster modification of Cu species on a TiO2 support is achieved. Effective engineering of Cu valence is achieved, where the surface Cu+ content varies from 15% to as high as 100%. Meanwhile, a high percentage (70–80 mol%) of TiO2 photocatalytic active phase (anatase) is also maintained in the flame‐made catalysts. A dramatic enhancement in photocatalytic H2 evolution efficiency of the hybrid catalyst is attained. The maximum photocatalytic H2 evolution rate of the hybrid CuOx/TiO2 catalyst under Xe lamp in a methanol aqueous solution can reach as high as 112.6 µmol h−1, which is ≈22.1 times higher than that of commercial P25 TiO2. Mechanism investigation via density functional theory calculation and photoluminescence spectra validates that the bulk defect levels and surface‐deposited CuOx nanoclusters play key roles in charge separation and extending spectral response.

Premixed Stagnation Flame Synthesized TiO2 Nanoparticles with Mixed Phases for Efficient Photocatalytic Hydrogen Generation

Mixed-phase TiO2 nanoparticles (10–20 nm) composed of rutile, anatase, and srilankite phases are prepared through a one-step flame synthesis method. The phase composition of TiO2 nanoparticles can be easily tuned by changing the flame conditions such as the gas flow rates of the fuel, oxygen, and argon carrier. The optimized anatase/rutile/srilankite TiO2 sample with as low as 0.1 wt % of Pt cocatalyst exhibits remarkable photocatalytic H2 generation rate of 21.9 mmol h–1 g–1 and an apparent quantum efficiency (AQE) of 39.4% at 360 nm, higher than those of anatase/rutile or anatase TiO2. The less studied srilankite phase is first time investigated for photocatalytic H2 generation. It is revealed that the relatively low content of srilankite phase in TiO2 could efficiently promote charge separation and transportation. It is remarkable that, compared to the commercial P25 TiO2, the flame-made TiO2 significantly improves Pt reduction and dispersion owing to the oxygen vacancies and surface defects. The optim...

Hydrothermal synthesis, growth mechanism, optical properties and photocatalytic activity of cubic SrTiO3 particles for the degradation of cationic and anionic dyes

Cubic SrTiO3 particles were synthesized by a hydrothermal reaction method under the alkaline condition using commercial P25 TiO2 and Sr(OH)2∙8H2O powders as the starting materials. It is demonstrated that the hydrothermal reaction duration time has a strong influence on the phase purity, surface morphology, optical properties and photocatalytic activity of prepared samples. The effect of hydrothermal reaction duration time, pH value, dye concentration and catalyst dosage on the photocatalytic activity of the phase-pure cubic SrTiO3 was investigated by the degradation of cationic and anionic dyes under simulated sunlight irradiation. At normal pH condition (pH = 6), the cubic SrTiO3 exhibits a higher photocatalytic activity toward the degradation of the anionic dye CR than the degradation of other cationic dyes including RhB, MB and MO. The growth mechanism and photocatalytic mechanism of the cubic SrTiO3 were systematically investigated and discussed.

Photocatalysis and Hydrogen Evolution of Al- and Zn-Doped TiO2 Nanotubes Fabricated by Atomic Layer Deposition.

Highly homogeneous Al- and Zn-doped TiO2 nanotubes were fabricated by atomic layer deposition (ALD) via nanolaminated stacks of binary layers of TiO2/Al2O3 and TiO2/ZnO, respectively. The bilayers were alternately deposited on the polycarbonate (PC) membrane template by ALD with various cyclic sequences. The nanotubes in a length of 20 μm and a diameter of 220 nm were obtained after removal of the PC membrane by annealing at 450 °C. The effects of doping composition on the photocatalytic and photoelectrochemical (PEC) activities were investigated. Increasing the Al doping reduced the photocatalytic activity of TiO2 due to formation of charge recombination sites and reduction of hydroxide radicals. In contrast, there was an optimal range of Zn doping to get enhanced photocatalytic activity and higher PEC efficiency. With a doping ratio of 0.01, the hydrogen production rate from water splitting was 6 times higher than that of commercial P25 TiO2. The energy-band diagram of Zn-doped TiO2 determined by ultraviolet photoelectron spectroscopy revealed shift up of the Fermi level to provide more electrons to the conduction band. The photoinduced trapped electrons and holes were detected in Zn-doped TiO2 by in situ electron paramagnetic resonance spectroscopy, which revealed that Ti3+ sites on the surface and surface oxygen vacancies played a key role in promoting the photocatalytic process.

Degradation of methylene blue and methyl orange by palladium-doped TiO2 photocatalysis for water reuse: Efficiency and degradation pathways

This work prepared palladium-doped titanium dioxide (Pd-doped TiO2) catalysts by a facile sol-gel method to enhance degradation of single and binary methylene blue and methyl orange by ultraviolet photocatalysis. The physicochemical properties of Pd-doped TiO2 particles were analyzed by a X-ray powder diffractometer, X-ray photoelectron spectroscope, scanning electron microscope, transmission electron microscope, UV–visible diffuse reflectance spectroscope, sorptiometer, and transient photocurrent spectroscope. More efficient degradation was achieved in acidic and basic/neutral media for methyl orange and methylene blue, respectively. Also, methylene blue was always degraded faster than methyl orange. The highest degradation efficiency of both dyes in single and binary systems was obtained using 0.5 wt.% and 0.75 wt.% PdTiO2, respectively. The degradation pathways of single methylene blue and methyl orange with Pd-doped TiO2 and commercial P25TiO2 were proposed and compared by identifying reaction intermediates produced during photocatalysis. Recycling tests have confirmed excellent stability of PdTiO2 materials. Also, the prepared materials were easier to separate from the treated liquid using a simple sedimentation or filtration method than P25TiO2. In particular, the use of sol-gel method could readily synthesize a large number of catalysts, which was beneficial for scale up consideration. All these factors highlighted their potential and prospect in practical applications for water reuse.

Synergistic effect of oxygen vacancies and highly dispersed Pd nanoparticles over Pd-loaded TiO2 prepared by a single-step sol–gel process for deoxygenation of triglycerides

Renewable diesel has gained attention in recent years due to its superior fuel properties compared to the conventional biodiesel. The uses of Pd supported TiO2 (Pd/TiO2) and Pd supported activated carbon (Pd/C) catalysts for the deoxygenation of triglycerides to renewable diesel were investigated. Two different types of titania supports, i.e. mesoporous titania synthesized by a surfactant-assisted templating sol–gel method (SG-TiO2) and commercial P25-TiO2 (P25-TiO2), were used to investigate the effect of TiO2 crystal structure on the catalytic activity. The prepared catalysts were characterized by N2 adsorption-desorption isotherms, X-ray diffraction (XRD), H2 chemisorption, H2 temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The liquid products obtained from the deoxygenation of triglycerides in beef fat over the prepared catalysts at 325 °C, 500 psig, and H2/triglyceride molar ratio of 30 were in the diesel fuel specification range (C15-18). The main liquid products were n-heptadecane (n-C17) and n-pentadecane (n-C15), resulting from the decarboxylation or decarbonylation pathways. It was found that the Pd/P25-TiO2 catalyst exhibited a higher catalytic performance compared to the Pd/C catalyst. The formation of defects (oxygen vacancies and Ti3+) on TiO2, Pd dispersion and inducement of SMSI effect play an important role in the catalytic activity and the diesel yield on Pd/SG-TiO2 catalysts. Furthermore, the Pd incorporation methods, i.e. incipient wetness impregnation (IWI), photochemical deposition (PCD) and single-step sol–gel (SSSG), were also investigated. The Pd/TiO2 prepared by SSSG method exhibited the highest conversion of beef fat and selectivity to the diesel fuel (C15-18) which could be due to its well-dispersed Pd nanoparticles with relatively small size, high defects on TiO2 support and strong SMSI behavior.

TiO2-carbon quantum dots (CQD) nanohybrid: enhanced photocatalytic activity

In situ synthesized carbon quantum dot (CQD)-titanium dioxide (TiO2) nanostructures were found to exhibit excellent photocatalytic dye degradation properties. CQDs were synthesized by solvothermal decomposition of PEG in basic pH in presence of NaOH and their morphology and photophysical properties were studied. Nanostructures were produced by synthesizing CQDs in the presence of (a) commercial TiO2 [CQD/TiO2-P25] and (b) TiO2 precursor [CQD/TiO2] to obtain co-synthesized nanostructures. The photocatalytic properties of the hetero-structures, was also studied and compared with those of commercial TiO2-P25 and synthesized TiO2. The photocatalytic degradation rates of methylene blue were found to rise in the order of TiO2-P25 (2.00 × 10−3 min−1), synthesized TiO2 (6.7 × 10−3 min−1), CQD/TiO2-P25 (1.31 × 10−2 min−1) and CQD/TiO2 (3.6 × 10−2 min−1) respectively. The highest degradation rate for CQD/TiO2 among the samples is attributed to the superior interface between the CQDs and the TiO2, leading to higher interfacial charge transfer. The observed 18-fold increase in degradation rate for CQD/TiO2 over commercial TiO2-P25 photocatalyst and the over two-fold increase over CQD/TiO2-P25 photocatalyst, has significant techno-commercial implications, making CQD/TiO2 a promising photocatalyst.

Degradation and Loss of Antibacterial Activity of Commercial Amoxicillin with TiO2/WO3-Assisted Solar Photocatalysis

In this study, a TiO2 catalyst, modified with tungsten oxide (WO3), was synthesized to reduce its bandgap energy (Eg) and to improve its photocatalytic performance. For the catalyst evaluation, the effect of the calcination temperature on the solar photocatalytic degradation was analyzed. The experimental runs were carried out in a CPC (compound parabolic collector) pilot-scale solar reactor, following a multilevel factorial experimental design, which allowed analysis of the effect of the calcination temperature, the initial concentration of amoxicillin, and the catalyst load on the amoxicillin removal. The most favorable calcination temperature for the catalyst performance, concerning the removal of amoxicillin, was 700 °C; because it was the only sample that showed the rutile phase in its crystalline structure. Regarding the loss of the antibiotic activity, the inhibition tests showed that the treated solution of amoxicillin exhibited lower antibacterial activity. The highest amoxicillin removal achieved in these experiments was 64.4% with 100 ppm of amoxicillin concentration, 700 °C of calcination temperature, and 0.1 g L−1 of catalyst load. Nonetheless, the modified TiO2/WO3 underperformed compared to the commercial TiO2 P25, due to its low specific surface and the particles sintering during the sol-gel synthesis.