Figure 6 - uploaded by Sanja Zivkovic
Content may be subject to copyright.
Source publication
1) Background: An increasing use of pharmaceutics imposes a need for the permanent development of efficient strategies, including the tailoring of highly specific new materials for their removal from the environment. Photocatalytic degradation has been the subject of increasing interest of the researchers in the field. (2) Methods: This paper is fo...
Contexts in source publication
Context 1
... can be seen, there are only slight differences in the crystalline properties of these two materials, whereby the crystallites are slightly larger in TiO 2 (Cu). SEM images and EDX spectra of prepared (Cu)TiO 2 and bare TiO 2 samples are represented in Figure 6. SEM images (Figure 6) of bare TiO2 reveal variable-shape agglomerates of sph nanoparticles of about 1 µm in diameter. ...
Context 2
... images and EDX spectra of prepared (Cu)TiO 2 and bare TiO 2 samples are represented in Figure 6. SEM images (Figure 6) of bare TiO2 reveal variable-shape agglomerates of sph nanoparticles of about 1 µm in diameter. The (Cu)TiO2 sample exhibits a similar stru although the average size of agglomerates is lower compared to bare TiO2. ...
Context 3
... (Cu)TiO2 sample exhibits a similar stru although the average size of agglomerates is lower compared to bare TiO2. The av diameter of nanospheres in (Cu)TiO2 is also lower compared to bare TiO2 (about 10 being comparable with an average crystallite size obtained from a Debye-Scherrer Figure 6. SEM images and EDX spectra of (a) (Cu)TiO 2 and (b) bare TiO 2 at the magnification ×20,000. ...
Context 4
... images (Figure 6) of bare TiO 2 reveal variable-shape agglomerates of spherical nanoparticles of about 1 µm in diameter. The (Cu)TiO 2 sample exhibits a similar structure, Materials 2023, 16, 5708 9 of 15 although the average size of agglomerates is lower compared to bare TiO 2 . ...
Context 5
... EDX pattern ( Figure 6) confirms the presence of Cu in the (Cu)TiO 2 sample. Moreover, elemental maps of (Cu)TiO 2 (Figure 7) confirm that copper and oxygen follow similar and rather uniform spatial distribution-oxygen-rich areas are also rich in copper-confirming the preposition of prevalent Cu-O binding at low Cu loadings from DFT calculations. ...
Similar publications
In this study, the synthesis and characterization of the TiO2 and Ag/TiO2 nanoparticles were carried out and their influence on the oxidation of organic matter of domestic wastewater was evaluated using a heterogeneous photocatalytic system. The TiO2 and Ag/TiO2 nanoparticles were synthesized by the sol–gel method and the chemical reduction method....
Citations
... Research conducted so far has shown that semiconductors like metal oxides (TiO 2 , SnO 2 , Fe 2 O 3 , WO 3 , ZnO, Ag 3 O 4 , Nb 2 O 5 , CeO 2 , MoO 3 , ZrO 2 ), metal sulfides (ZnS, CdS), and g-C 3 N 4 -based materials are promising photocatalysts [16,[18][19][20]. The wide range of uses for TiO 2 can be attributed to its excellent optical and electronic properties, high chemical and biological stability, low cost and availability, non-toxicity, resistivity towards corrosion, and eco-2 of 21 friendliness [21][22][23][24], despite its large band gap and minimal utilization of the UV area of sunlight [25]. Some experimental strategies used to reduce band gap are element doping, coupling with other semiconductors, synthesis of nanostructures with particular morphologies, surface sensitization using organic dyes, and the use of metal-based structures [26][27][28]. ...
Optimization of the efficiency of the photocatalytic degradation of organic and pharmaceutical pollutants represents a matter of fundamental and practical interest. The present experimental and DFT study deals with evaluation of OH radical binding energy as a simple computational descriptor of the catalytic activity of d-metal-decorated TiO2 photocatalysts for the photodegradation of the widely used antibiotic ciprofloxacin. Five d-metals commonly used in catalytic materials (Zr, Pt, Pd, Fe, and Cu) were deposited on the TiO2 surface, and the obtained photocatalysts were characterized experimentally (XRPD, ICP-OES, and SEM) and theoretically (DFT). Attention was also paid to the mechanistic insights and degradation byproducts (based on UV-Vis spectrometry and LC/MS analysis) in order to obtain systematic insight into their structure/performance relationships and confirm the proposed model of the degradation process based on OH radical reactivity.
... The introduction of atomic-scale defects Ti 3+ and VO in the L15TiO2 and L30TiO samples was a crucial step that significantly reduced the recombination of eˉ and h thereby improving the photocatalytic activity of the irradiated samples. To better unde stand the rate of photocatalytic degradation of CBF with laser-irradiated TiO2 photo catalysts, kinetic constants were calculated following the formula for pseudo-first-orde kinetics (Equation (3)) [53]: (3 where k1 is the pseudo-first-order rate constant, and Co and C are the CBF concentration at time t = 0 min and t = t min, respectively. The kinetic constants for the degradation o CBF with TiO2, L15TiO2, and L30TiO2 are 0.0024 min −1 , 0.0033 min −1 , and 0.0051 min − respectively (Figure 7c), and the linear regression correlation coefficients of the degrada tion experiment kinetic processes were 0.976, 0.982, and 0.981 for TiO2, L15TiO2, an L30TiO2, respectively. ...
... The CBF degradation half-times can be determined from rate con The introduction of atomic-scale defects Ti 3+ and V O in the L15TiO 2 and L30TiO 2 samples was a crucial step that significantly reduced the recombination of e and h + , thereby improving the photocatalytic activity of the irradiated samples. To better understand the rate of photocatalytic degradation of CBF with laser-irradiated TiO 2 photocatalysts, kinetic constants were calculated following the formula for pseudo-first-order kinetics (Equation (3)) [53]: where k 1 is the pseudo-first-order rate constant, and Co and C are the CBF concentrations at time t = 0 min and t = t min, respectively. The kinetic constants for the degradation of CBF with TiO 2 , L15TiO 2 , and L30TiO 2 are 0.0024 min −1 , 0.0033 min −1 , and 0.0051 min −1 , respectively (Figure 7c), and the linear regression correlation coefficients of the degradation experiment kinetic processes were 0.976, 0.982, and 0.981 for TiO 2 , L15TiO 2 , and L30TiO 2 , respectively. ...
This study proposes a simple and controlled method for producing TiO2 with phase junction, oxygen vacancies, and Ti3+ by combining picosecond pulsed laser irradiation and electrochemical anodization. Ti mesh was pretreated by irradiating with a picosecond pulsed laser technique using an Nd:YAG laser (1064 nm) at two fluencies, 15 J/cm2 and 30 J/cm2. The samples were then subjected to electrochemical anodization to form TiO2 nanotube arrays on the previously laser-treated surface. This study will investigate the possibility of forming TiO2 nanotube arrays on a pre-laser-treated Ti substrate and determine their physicochemical and photocatalytic properties. The samples were characterized by FESEM, XRD, Raman, XPS, and UV-Vis DRS. UV-Vis spectroscopy was used to observe the progress of photocatalytic degradation for all samples, and degradation products were determined using GC-MS. With the synergistic effects of phase junction, oxygen vacancies, and Ti3+, the laser-treated TiO2 with 30 J/cm2 showed a higher photocatalytic degradation rate (85.1%) of the pesticide carbofuran compared to non-laser-treated TiO2 (54.8%), remaining stable during successive degradation cycles, which has promising practical applications.
The presence of pharmaceutically active compounds (PhACs) in surface and groundwater has become a major distress owing to harmful effects on humans and the environment. Therefore, PhACs effluents from various industrial and healthcare facilities must be treated appropriately to protect environmental health. Herein, we have developed visible light-driven Cu0-8.24/TiO2 photocatalysts via a bio-analytic route using ascorbic acid-rich S. edule vegetal extract. The Cu-doping process was performed in two steps: (i) loading of Cu(II) precursor onto TiO2, and (ii) its doping into TiO2 lattice using S. edule vegetal extract. The prepared Cu-doped TiO2 photocatalysts were characterized to analyze optical, structural, and morphological properties and utilized for ciprofloxacin (CIP) degradation under visible light. Cu(II) loading was optimized at pH 7 with adsorption of 95.7 % at an initial Cu(II) concentration of 7 % (w/w). Cu doping decreased the bandgap to 2.39 eV (from 3.29 eV), shifting the light absorption edge from 377 to 519 nm in Cu6.70/TiO2(bio). Furthermore, FETEM analysis, electron paramagnetic resonance (EPR), photoluminescence (PL), and water contact angle results revealed increased average particle size (from 21.07 to 22.42 nm), more oxygen vacancies, delayed recombination, and high hydrophilicity of Cu-doped TiO2 over Cu0.00/TiO2(bare). Cu6.70/TiO2(bio), with the lowest bandgap, exhibited a superior CIP degradation of 71.4 ± 2.8 % with a rate constant of 1.39 × 10−2 min−1, and quantum yield of 17.6 ± 0.35 % than that of Cu0.00/TiO2(bare), which exhibited degradation of 49.9 ± 2.0 %, rate constant of 1.12 × 10−2 min−1, and a quantum yield of 12.3 ± 0.24 %. Hence, the prepared Cu-doped TiO2 exhibits potential for higher-scale use for photocatalytic degradation of PhACs under visible light.
The study presents a breakthrough of a balanced charge separation for heterojunction CuWO4-TiO2 cocatalyst to efficiently enhance visible light photocatalytic degradation of ciprofloxacin (CIP). A solvothermal-synthesized nanopyramid-like CuWO4 semiconductor was assembled before sol–gel treatment with TiO2 precursors to generate CuWO4-TiO2 nanocomposites. The optical, structural, and morphological properties of CuWO4-TiO2 were elucidated using UV–Vis DRS, XRD, FTIR, Raman spectroscopy, and TEM/SEM techniques. The UV–Vis DRS spectroscopy of as-synthesized CuWO4-TiO2 cocatalyst demonstrated enhanced visible light absorbance. The XRD patterns of CuWO4-TiO2 revealed a triclinic phase nanocrystal. The O-Ti–O functionality was confirmed by FTIR spectroscopy. The photoactive bands corresponding to anatase redshift were observed from Raman spectroscopy of CuWO4-TiO2 nanocomposite. The PL studies attributed this redshift to the elevated extra energy bands that aid electron/hole pair charge separation in a co-catalyst heterojunction CuWO4-TiO2 nanocomposite afforded by embedding CuWO4-MOF within TiO2 crystalline. The TEM showed that un-sintered CuWO4.MOF mimicked a pyramidal shape and converted to nanoflakes upon sintering, while TiO2 and CuWO4-TiO2 retained a tetragonal shape. The photocatalytic activity of CuWO4-TiO2 cocatalyst was studied using CIP, as a model pollutant. The innovative design of 5CuWO4-TiO2 charge separation nanocomposite completely degraded 10 mg L−1 CIP solution at pH = 6.31 (natural pH) and 9 under 120 min of sunlight irradiation.
Antibiotics, as emerging pollutants, cause a range of environmental issues due to their toxic and mutagenic effects, making their removal challenging. The objective of this study is to create a novel and promising photocatalyst. Cu-TiO2-Aluminosilicate nanocomposite was successfully synthesized using a solvothermal process. A range of analytical techniques were employed to characterize Cu-TiO2-Aluminosilicate nanocomposite, like SEM, XRD, UV-Vis, FTIR, BET, and TGA. The Taguchi method of experimental design (L16) was employed to optimize the photocatalysis process and determine the significance of investigated operating variables such as pH (2–8), photocatalyst dose (0.1–0.4 g/L), initial concentration (10–25 mg/L) and temperature (298–328 K). The experimental findings demonstrated that Cu-TiO2-Aluminosilicate nanocomposite exhibited a remarkable photocatalytic activity. The maximal photocatalytic degradation achieved was 89.95% with optimum conditions of pH 4, dosage 0.1 g/L, initial concentration 15 mg/L, and temperature 318 K. The significance of the model was validated using analysis of variance (p < 0.05). Among the factors studied, pH, temperature and initial concentration were found the most influential. Additionally, the first-order kinetic model (R² = 0.994) demonstrated the strongest correlation with the experimental data indicated by the kinetic study results. The results of reusability experiments showed that prepared nanocomposite maintains its reusability from 89.95 to 68% after three cycles of application. The toxicity assessment of the treated solutions revealed higher cell viability in Scenedesmus and Chlorella sp. Therefore, based on the comprehensive findings, it can be concluded that Cu-TiO2-Aluminosilicate nanocomposite is a novel photocatalyst for effective removal of antibiotics.
