Commercial P25 TiO2 Research Articles

Flexible electrospun PET/TiO2 nanofibrous structures: Morphology, thermal and mechanical properties

AbstractIn this study, a solvothermal method was used to synthesize anatase titanium dioxide (TiO2) nanoparticles in the presence of oleic acid (OA) and oleylamine (OM) as morphology‐directing agents. Functional nanocomposite fibers of poly(ethylene terephtalate) (PET) containing surfactants‐capped TiO2 nanoparticles were developed by electrospinning technique. The morphology, thermal stability and mechanical properties of PET/TiO2 nanocomposite mats were investigated as a function of TiO2 concentration. Morphology investigation showed interesting results in terms of the level of TiO2 dispersion inside the fibers and the improvement of the quality (smoothness) of the fibers' surface when the synthesized nanorhombic TiO2 nanoparticles were used compared to a commercial P25 TiO2 (AEROXIDE P25). The presence of OA and OM on the surface of the nanorhombic synthesized TiO2 led to a significant improvement of TiO2 dispersion inside the PET matrix. Furthermore, the physical interaction between the PET matrix and TiO2 nanoparticles resulted in an enhanced thermal stability, and an increase of the Young's modulus and tensile strength for TiO2 concentration up to 10 wt%.

Photocatalysts for H2 Generation from Starburst Triphenylamine/Carbazole Donor-Based Metal-Free Dyes and Porous Anatase TiO2 Cube.

A series of novel triphenylamine/carbazole-based D-D-π-π-A dyes DH1-4 and a mesoporous anatase cubic "microcage" TiO2 material (denoted as MC-TiO2 ) were synthesized and combined to obtain dye-sensitized photocatalysts (denoted as DHn/Pt/MC-TiO2 , n=1-4). These catalysts showed better performances in visible-light-driven H2 evolution from water than DHn/Pt/P25-TiO2 catalysts based on commercial P25-TiO2 bulk semiconductor under similar conditions. Compared with P25-TiO2 particles, the porous MC-TiO2 had a large Brunauer-Emmett-Teller surface area, porosity, and exposed {0 0 1} crystal plane, which greatly contributed to the photocatalytic activity. The optimized DH2/Pt/MC-TiO2 photocatalyst exhibited an attractive H2 production rate (16.28 mmol g-1 h-1 based on catalyst mass), and the optimized DH4/Pt/MC-TiO2 photocatalyst showed good stability [turnover number (TON) of 16 699 in 105 h based on dye number], which represents one of the best performances among all reported visible-light-driven heterogeneous catalytic systems. Compared with the other dyes in this series, the high H2 production rate of DH2 on Pt/MC-TiO2 can be attributed to its size-matching effect and thus high dye loading amount, whereas the high TON and durability of DH4/Pt/MC-TiO2 are probably related to the rapid regeneration kinetics of DH4.

Comparison of TiO2 nanowires and TiO2 nanoparticles for photodegradation of resorcinol as endocrine model

In this contribution, comparison of TiO2 nanowires (TiO2 NWs) and TiO2 nanoparticles (TiO2 NPs) for photodegradation of resorcinol as endocrine model was extensively carried out. The results indicated that X-ray diffraction (XRD) patterns of the TiO2 NWs exhibited brookite and anatase phases; whereas, the prepared TiO2 NPs is pure anatase phase. TEM images of TiO2 NWs exhibit clear nanowire structures with the 2 μm length and diameter of 50–100 nm, while the TiO2 NPs particle sizes are 5–10 nm. The prepared TiO2 NWs and TiO2 NPs were compared with commercial photocatalyst TiO2-P25 by the determination of their photocatalytic performances. The photocatalytic efficiencies of TiO2 NWs, TiO2 NPs, and TiO2 P25 are amounted to be 98.7%, 98.4%, and 83% within 3-h illumination. However, the photodegradation rates TiO2 NPs, TiO2 NWs, and TiO2-P25 are 12.24 × 10−7 mol L−1 min−1, 10.79 × 10−7 mol L−1 min−1, and 5.77 × 10−7 mol L−1 min−1, i.e., the photodegradation rates TiO2 NPs is slightly faster than TiO2 NWs, and they are significantly greater 2 times than that of commercial photocatalysts TiO2-P25. The apparent rate constant k (min−1) value of TiO2 NPs and TiO2 NWs is higher than that of commercial TiO2-P25 for 3.3 and 3.25 times, respectively. From the economic point of view, TiO2 NPs calcined at 400 °C are chosen to be the optimum for saving energy in the preparation step without loss of photocatalytic efficiency.

One-step fabrication of highly self-hydroxylated TiO2 mesocrystals and photocatalytic behavior towards water splitting

TiO2 mesocrystals have been considered as an efficient photocatalyst due to the effective charge transport. Introducing hydroxyls in TiO2 is respected to reduce the energy barrier of hydrogen formation. Herein, a simple one-step fabrication of highly self-hydroxylated TiO2 mesocrystals (MCs) for enhancing photocatalytic hydrogen evolution is proposed. TiO2 single crystals (SCs), polycrystals (PCs) and MCs are obtained via regulating the pH of the precursor during hydrothermal treatment. Results indicate that the moderate alkaline condition is favorable for the synthesis of highly self-hydroxylated TiO2 MCs. Compared with SCs, PCs and commercial P25 TiO2 nanoparticles, MCs exhibit the best photocatalytic activity in H2 evolution. Specifically, the maximum hydrogen evolution rate under solar light illumination (22.8 mmol/h/g) is 10.5 times higher than that of P25. Moreover, the MCs exhibit excellent catalytic stability and the hydrogen evolution rate can be maintained at 20.8 mmol/h/g under solar illumination after five cycles of reactions. The highly self-hydroxylated TiO2 MCs are constructed from crystallographically oriented nanocrystals with abundant hydroxyls. The unique superstructure and large surface area of MCs enable the effective charge separation and transport. Moreover, the high density of hydroxyls can reduce the recombination rate of photo-generated free charges and energy barrier for hydrogen formation while facilitate light absorption. The synthesis of highly self-hydroxylated TiO2 MCs and the underlying mechanism offer interesting insights for modifying the structure and properties of TiO2 towards high-performance hydrogen evolution.

Formation of hollow porous TiO2 nanospheres via the encapsulation of CO2 nanobubbles for high-performance adsorption and photocatalysis.

Porous TiO2 structures have been of great interest in various photocatalytic applications over the past decade. However, the synthetic methods reported so far in the literature are complex and time consuming. This study presents a simple one-pot fabrication method of hollow porous TiO2 nanospheres using a sol-gel process involving CO2 generation in aqueous solution. The CO2 nanobubbles produced in the reaction act as a template for the crystal growth of TiO2 resulting in highly porous hollow nanospheres. The unique nanocrystal structure with a hollow nanosphere centre surrounded by an outer shell of prickle-like porous nanocrystals was observed. The prepared hollow porous TiO2 nanospheres exhibited excellent adsorption properties as demonstrated by the adsorption measurements and dynamic extraction of methylene blue in aqueous solution. Furthermore, the hollow porous TiO2 nanospheres hydrothermally treated at 180 °C exhibit 3.2 times higher photocatalytic performance in the decomposition of methylene blue than the commercial P25 TiO2. The idea of this work provides a new direction for facile green synthesis routes of various metal oxides with cavities, channels or crevices for various technological applications.

Blue ordered/disordered Janus-type TiO2 nanoparticles for enhanced photocatalytic hydrogen generation

A Janus-type heterojunction between ordered-anatase and disordered-rutile phases was fabricated by selectively disordering the rutile phase of commercial P25-TiO2, and exhibits a ∼13-fold enhancement in photocatalytic H2 production relative to untreated P25-TiO2.

Preparation of floatable TiO 2 /poly(vinyl alcohol)‐alginate composite for the photodegradation of ammonia wastewater

The use of floatable photocatalyst supports is an operable strategy of increasing photocatalytic performance in terms of improving light absorption. In this work, floatable organic support based on poly(vinyl alcohol) (PVA) was used to float commercial TiO2 P25 nanoparticles. At first, by the use of CaCl2 and boric acid at pH 3 the cross-linking of PVA blended with sodium alginate (PVA-Alg) was improved to enhance chemical and mechanical stability, and then it was chemically modified by trimethylchlorosilane to achieve floatable organic support (modified or MPVA-Alg). The prepared support and photocatalyst were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX)-elemental mapping, inductively coupled plasma optical emission spectroscopy, ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, photoluminescence (PL), thermalgravimetry, Brunauer-Emmett-Teller (BET), and water contact angle (WCA) analyses and applied for the ammonia degradation under UV to visible regions. Results of WCA and FTIR confirmed that chemical modification of PVA-Alg led to lowering hydrophilicity to be floated on the ammonia wastewater. UV-vis analysis indicated that the MPVA-Alg acts as a light absorbent in UV-vis ranges and makes TiO2/MPVA-Alg a visible light active composite. Also, the PL analysis showed that the charge recombination process was strongly suppressed in the case of the TiO2/MPVA-Alg sample. BET theory suggested that the textural properties were not the key factor in determining photocatalytic performance. The maximum photocatalytic ammonia removal was obtained to be 63% and 57% by the TiO2/MPVA-Alg composite under UV-vis light irradiations, respectively. The MPVA-Alg and TiO2 exhibited the ammonia degradation of 28.5% and 15.2% under visible and 29.4% and 40.0% under UV irradiation, respectively. The TiO2/MPVA-Alg showed favorable reuse ability after five runs due to desirable chemical and mechanical resistance. This study provides an insight into the modification of polymeric structures to be used as both floatable photocatalyst support and light sensitizer.

Selective removal of organic and inorganic air pollutants by adjusting the g-C3N4/TiO2 ratio

During the recent years, g-C3N4/TiO2 composites have been regarded as efficient photocatalysts for the removal of air pollutants. The combination of these materials gives excellent photocatalytic performances, as each ones advantage covers the disadvantages of the other. In the present study, g-C3N4/TiO2 heterostructures were synthesized by mixing chemically exfoliated g-C3N4 with commercial TiO2 P25 in different ratios and were examined for the removal of NOx and acetaldehyde under visible-light irradiation. The results of photocatalytic tests in correlation with the EPR experiments revealed that heterostructures containing higher amount of TiO2 are efficient in systems where the attack of hydroxyl radicals prevails (acetaldehyde), while dominant g-C3N4 content provides effectiveness in systems where superoxide radical anions play the key role (NOx). This outcome is directly coupled with the energy positions of conduction- and valence-band edges of each material.

High‐Efficiency Photocatalysis of Self‐Hydroxylated TiO2 Nanocrystals for Water Splitting

AbstractHerein, a facile and controllable strategy to synthesize self‐hydroxylated TiO2 nanocrystals with promoted photocatalytic activity in hydrogen evolution is demonstrated. Various colors (yellow, light yellow, blueish gray and gray) in appearance are induced by controlling the molar ratio of titanium source to oxidant during the hydrothermal treatment. Compared with commercial P25 TiO2 nanoparticles, the as‐obtained self‐hydroxylated TiO2 nanocrystals exhibit better photocatalytic performance in H2 evolution. Specifically, the maximum hydrogen evolution rate under solar light illumination (10.0 mmol/h/g) is 4.6 times superior to that of P25. The characterization results confirm the presence of abundant hydroxyls resulting from the hydrothermal treatment, which decreases the recombination rate of carriers and the energy barrier of hydrogen formation while facilitates light absorption for promoting photocatalytic performance.

Self-assembly TiO2 nanosheets as a SALDI-TOF-MS matrix for high-throughput identification of polyfluorinated compounds in water samples

Concerns about bioaccumulation, persistence and toxicity have led to a lot of researches on perfluorinated compounds (PFCs). In order to identity PFCs in real sample, self-assembled TiO2 nanosheets (TiO2 NS) were fabricated by an one-step hydrothermal method and applied as matrix for the surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) detection of PFCs. Compared to the commercial P25 TiO2, the proposed self-assembled TiO2 nanosheets matrix is better reproducibility and higher sensitivity benefiting from the unique hexagon structure of TiO2 NS. 22 and 12 PFCs have been detected in water samples collected from locations near the outlets of a factory and a waste-water treatment plant, respectively. The proposed method can be a promising tool for high-throughput detect of trace PFCs in real samples.

Structural and photochemical properties of Fe-doped ZrO2 and their application as photocatalysts with TiO2 for chromate reduction

In this work, we are interested by the photocatalytic activity under sunlight irradiation of Fe-doped ZrO2 prepared by co-precipitation. The structural and photophysical properties of the catalysts have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), BET method and UV–Vis diffuse reflectance. The results show that Fe-doped ZrO2 exhibits higher photocatalytic activity than that of both ZrO2 and commercial TiO2 P25. The best photocatalytic activity is obtained with the 50 mol% Fe-content calcined at 600 °C/ 3 h. A total photoreduction of Cr(VI) is achieved within 90 min under solar light with the new hetero-junction Fe-ZrO2/TiO2. The kinetic of Cr(VI) photoreduction is well described by the Langmuir-Hinshelwood (LH) model which obeys to pseudo-first-order kinetics with a rate constant of 0.031 min−1. On the basis of the energy band positions of the hetero-junction Fe-ZrO2/TiO2, the detailed reaction mechanism of reduction of inorganic pollutant has been discussed.

Influences of solvothermal-assisted crystallization process on the microstructure and properties of SiO2-W0.02TiO2.06 composite aerogels synthesized via ambient pressure drying

In this work, the influence of solvothermal crystallization processes on the microstructure, pore characteristic, and adsorption/photocatalysis of SiO2-W0.02TiO2.06 composite aerogels synthesized via ambient pressure drying have been investigated. It has been clarified that the composite aerogels prepared via solvothermal crystallization at 120 °C for 0.5 h and 180 °C for 3 h exhibited high-specific surface area (416–729 m2/g) and pore volume (2.26–2.70 cm3/g). With the increase of solvothermal crystallization temperature and time, the crystallinity of composite aerogels increased gradually, but excessive solvothermal crystallization time at higher temperature decreased the pore volume greatly. Furthermore, it is found that bacterial cellulose (BC) in the composite gel plays an important role in enhancing the pore volume and crystallization of the SiO2-W0.02TiO2.06 composite aerogels as a pore-expanding agent and structure-directing agent. The as-synthesized SiO2-W0.02TiO2.06 composite aerogels exhibited higher adsorption and removal efficiency for RhB than the commercial P25-TiO2, which can be ascribed to its high pore volume and specific surface area, as well as the synergistic action of adsorption and photocatalysis.

An ideal visible nanocomposite (Fe/GTiP) photoanode catalyst for treatment of antibiotics in water and simultaneous electricity generation in the photocatalytic fuel cell

The photocatalytic fuel cell (PFC) has been studied for the wastewater treatment and electricity generation by degrading antibiotic organic pollutant berberine chloride (BC). Through a simple chemical process Fe/GTiP anode and ZnIn2S4 cathode catalysts were prepared and loaded them on carbon fiber cloth. Up to 79% BC (10 mg/L) was removed with simultaneous electricity generation of 0.65 V within 90 min under pH-7 in PFC by using visible light (two 50-W halogen lamps). PFC is better with 79% BC removal and electricity generation than only 79% removal in photocatalysis (PC) without generating any clean energy. Under photocatalysis Fe/GTiP can remove 70% of BC, higher than 54% with GTiP and 12% with TiP at 50 mg catalyst/50 mL (10 mg/L BC). The photocatalytic performance of Fe/GTiP was also compared with commercial P25 and pure TiO2. The obtained removal of 17.4% and 13.25% BC (10 mg/L) with P25 and TiO2 proves that with more visible light absorption Fe/GTiP has significant photocatalytic effect than P25 and pure TiO2. The impacts of external resistance, concentration of catalyst, pH, and electrolyte were investigated in the PFC. Removal of tetracycline hydrochloride (TC) (10 mg/L) followed the same trend as BC under photocatalysis with Fe/GTiP, GTiP and TiP (78%, 60% and 33% at pH-7). The removal of 89% TC (30 mg/L) in 90 min was also achieved with Fe/GTiP. The experimental study shows that Fe/GTiP visible light nanocomposite is ideal for removing antibiotics in water by photocatalysis or with simultaneous electricity generation through PFC.

3D printed chitosan scaffolds: A new TiO2 support for the photocatalytic degradation of amoxicillin in water

TiO2-supported chitosan scaffolds (TiO2/CS) are here proposed as promising material for wastewater treatment, in particular for the removal of pharmaceutical compounds. TiO2/CS are tested for the amoxicillin photodegradation under UV/Vis irradiation. Amoxicillin (AMX) is an antibiotic of the beta-lactam family. Due to the release of antibiotics in wastewater and their persistence in the environment, harmful effects can develop on the aquatic and terrestrial organisms.TiO2 chitosan scaffolds with photocatalytic activity for wastewater remediation have been prepared by 3D printing using commercial P25-TiO2. The formulation for the 3D printer was prepared by dispersion of chitosan and TiO2 in powder form at the concentration 6% w/v and 1% w/v, respectively. The TiO2 particles (crystalline anatase and rutile phases) embedded in the chitosan have a size of about 20 nm, like in the starting material, as verified by X-ray diffraction and Raman spectroscopy and are homogeneously distributed in the scaffold, also after repeated photocatalytic tests, as revealed by SEM-EDS.The mechanical properties of the 3D structures are suitable for the targeted application as they can be easily handled without breakage.The AMX photodegradation efficiency under light irradiation by TiO2/CS made with scaffolds of different thicknesses (3, 5, 15 layers), was assessed in water by means of UV–Vis absorption and HPLC/UV measurements, at two different AMX:TiO2 molar ratios: 1/100 and 1/10. The 3D printed TiO2/CS system, even after repeated cycles, shows a high photodegradation efficiency, compared to the direct AMX photolysis. A zero-order kinetics for TiO2 supported photodegradation was found, whereas a pseudo-first order was observed for water dispersed TiO2.Mass spectrometry analysis revealed the presence of AMX degradates such as penilloic and penicilloic acids and diketopiperazine.The proposed 3D printed chitosan scaffolds may be used as reusable substrate for the TiO2 photocatalytic degradation of antibiotic pollutants in wastewater.

Doping TiO2 with CuSO4 enhances visible light photocatalytic activity for organic pollutant degradation.

Photocatalysis is one of the most promising advanced oxidation processes due to the capability of solid catalyst to continuously produce oxidant species under light irradiation. The use of conventional UV lamps is high cost intensive, which undermines the possible implementation in developing countries. Visible light active photocatalysts can overcome these challenges and find a market opportunity for competitive technology implementation. This work proposes the synthesis of visible light active catalyst following a facile sol-gel synthesis that introduces CuSO4 as dopant in TiO2. Results present complete abatement of methylene blue in 120min of treatment under 50mWcm-2 of blue light (λ = 450nm), while commercial P25 TiO2 presented null abatement under identical conditions. Synthesis parameters including dopant level and calcination temperature allowed defining optimum synthesis conditions based on material characteristics modification and catalytic activity enhancement. A doping level of 0.21mol% CuSO4 was identified as optimum condition to enable visible light photocatalysis of doped TiO2 catalysts calcined at 300°C. Finally, operational parameters were evaluated defining a wide range of pH operation under 3.0gL-1 of catalyst dose to treat up to 20gL-1 of highly recalcitrant phenothiazine dye. These optimum conditions allowed complete dye removal under visible light after 120min of treatment.

Photocatalytic Reduction of Benzophenone on TiO2: Effect of Preparation Method and Reaction Conditions

The photocatalytic reduction of benzophenone was studied focusing on improving the yield to benzhydrol. TiO2 was synthesized by means of a hydrothermal technique. TiO2 (Degussa TiO2-P25) was used as a reference. Catalysts were characterized by XRD and nitrogen physisorption. The photocatalytic reduction was carried out in a batch reactor at 25 °C under nitrogen atmosphere, acetonitrile as solvent and isopropanol as electron donor. A 200 W Xe-Hg lamp (λ= 360 nm) was employed as irradiation source. The chemical composition of the reaction system was determined by HPLC. Structural and textural properties of the synthesized TiO2 depended on the type of acid used during sol formation step. Using HCl, a higher specific surface area and narrower pore size distribution of TiO2 was obtained in comparison with acetic acid. As expected, the photochemical reduction of benzophenone yielded benzopinacol as main product, whereas, benzhydrol is only produced in presence of TiO2 (i.e. photocatalytic route). In general, the hydrothermally synthesized catalysts were less active and with a lower yield to benzhydrol. The optimal reaction conditions to highest values of benzhydrol yield (70-80%) were found at 2 g/L (catalyst loading) and 0.5 mM of initial concentration of benzophenone, using commercial TiO2-P25.

Enhanced Photocatalytic Degradation of 2-Butanone Using Hybrid Nanostructures of Gallium Oxide and Reduced Graphene Oxide Under Ultraviolet-C Irradiation

Hybrid nanostructures made of gallium oxide (Ga2O3) and reduced graphene oxide (rGO) are synthesized using a facile hydrothermal process method, where the Ga2O3 nanostructures are well dispersed on the rGO surface. The formed Ga2O3-rGO hybrids are characterized via Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), a diffuse reflectance Ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometer, Brunauer–Emmett–Teller (BET), and photoluminescence (PL). Gas chromatography mass spectrometry (GC-MS) was used for analyzing volatile organic compounds (VOCs). The photocatalytic activity of the hybrid nanostructures is evaluated via the degradation of the 2-butanone, representing the VOCs under 254-nm radiation in the atmosphere. That activity is then compared to that of the Ga2O3 and commercial TiO2-P25. The Ga2O3-rGO hybrid shows enhanced photocatalytic degradation of 2-butanone compared to Ga2O3 and TiO2-P25, which is attributed to the enhanced specific surface area. The results indicate that the Ga2O3-rGO hybrid could be a promising method of enhancing photocatalytic activity and thereby effectively degrading VOCs, including the 2-butanone.

Sonochemical Synthesis of Ce-doped TiO2 Nanostructure: A Visible-Light-Driven Photocatalyst for Degradation of Toluene and O-Xylene.

Ce-doped TiO2 nanostructures (CeT) with different amounts of Ce (0.5, 0.75, 1.0, 1.5, and 2.0 wt. %) were synthesized using a sonochemical processing method. The physicochemical properties of the prepared samples were explored using UV-visible diffuse reflectance spectroscopy (UV-vis DRS), field-emission TEM (FE-TEM), XRD, X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), and surface area and pore size analyzers. The photocatalytic performance of the prepared CeT was assessed by monitoring their degradation efficiencies for gaseous toluene and o-xylene—widely known as significant indoor air pollutants—under daylight irradiation. The prepared CeT exhibited significantly improved photocatalytic performance towards the degradation of toluene and o-xylene, which was much higher than that observed for pure TiO2 and commercial P25 TiO2. Particularly, photocatalytic degradation efficiencies by the prepared CeT catalysts increased remarkably in the case of o-xylene (up to 99.4%) compared to toluene (up to 49.1%). The degradation efficiency by the CeT was greatest for the CeT-0.75 sample, followed by, in order, CeT-1.0, CeT-0.5, CeT-1.5, and CeT-2.0 samples in agreement with the order of the surface area and the particle size of the catalysts. According to the change of light source, the average decomposition efficiencies for toluene and o-xylene by CeT-0.75 were shown in the order of conventional daylight lamp > violet light emitting diodes (LEDs) > white LEDs. The decomposition efficiencies normalized to supplied electric power, however, were estimated to be in the following order of violet LEDs > white LEDs > conventional daylight lamp, indicating that the LEDs could be a much more energy efficient light source for the photodecomposition of target toluene and o-xylene using the CeT-0.75 photocatalyst.

Efficient removal of methylene blue dye by a hybrid adsorption–photocatalysis process using reduced graphene oxide/titanate nanotube composites for water reuse

In this study, reduced graphene oxide/titanate nanotube (rGO/TNT) composites were fabricated by a one-step facile hydrothermal process. The structures and physicochemical properties of the prepared materials were comprehensively determined. The incorporation of a small amount of rGO into the composites led to the enhancement of the absorption intensity of visible light and the separation of photogenerated charged carriers. The rGO/TNT composite with the optimal amount of rGO of 3% by weight showed the highest photocatalytic activity for both methylene blue (MB) and methyl orange. Moreover, 3 wt.% rGO/TNT exhibited higher adsorption capability and photocatalytic activity for MB, a cationic dye, than TNTs and commercial TiO2 P25. The maximum amount of MB adsorbed on 3 wt.% rGO/TNT was 26.3 mg/g at 25 °C, and the adsorption rapidly reached equilibrium after 40 min of contact time. Approximately 100% decolorization and 77.4% mineralization over 3% rGO/TNT composite were achieved under 100 W UV irradiation for 1 h, whereas 95.0% decolorization and 78.8% mineralization were achieved under visible light irradiation for 3 h. The degradation pathways of MB over P25, TNTs, and 3 wt.% rGO/TNT composite were finally proposed and compared.

Photocatalytic abatement of emerging pollutants in pure water and wastewater effluent by TiO2 and Ce-ZnO: degradation kinetics and assessment of transformation products.

Here, the performances of two different catalysts, Ce-ZnO and TiO2 synthetized in our laboratories, were compared with the commercial TiO2-P25 for degradation of a mixture of seven emerging pollutants under UV irradiation. The investigation included monitoring pollutants abatement in Milli-Q water and in wastewater effluent and identifying their transformation products by HPLC-HRMS. Structural characterization of intermediates supported by data available from literature allowed elucidation of the transformation pathways occurring in the presence of all investigated catalysts in the wastewater effluent. Preliminary results showed a good removal efficacy for almost all examined contaminants, even in real water matrix (i.e. wastewater effluent). The type of matrix and catalyst affects the number and/or the abundance of transformation products, which suggests differences in their transformation routes.