Pure TiO2 Nanoparticles Research Articles

Photoluminescence and photocatalytic activity of sol gel synthesized Mg doped TiO2 nanoparticles

The influence of magnesium doping on the optical properties, structural characteristics, and photocatalytic performance of TiO2 nanoparticles was investigated. Pure and Mg-doped TiO2 nanoparticles with varying weight percentages of magnesium were synthesized via the sol–gel method, followed by calcination at 100 °C for 12 h and annealing at 400 °C for 2 h to promote crystallization. X-ray diffraction (XRD) analyses confirmed the formation of crystalline mixed phases of anatase and rutile TiO2 nanoparticles, exhibiting their crystalline nature upon synthesis. Scanning electron microscopy (SEM) images were employed to study the morphological features of the samples, while energy dispersive spectroscopy (EDS) provided insights into their elemental composition. Photoluminescence (PL) emission spectra revealed ultraviolet (UV) to visible region emission for both pure and doped TiO2 samples. The photocatalytic activity was evaluated by monitoring the degradation of methyl orange under natural sunlight irradiation, elucidating the impact of visible light exposure. Furthermore, investigations were conducted to assess the influence of catalyst loading, initial dye concentration, and pH of the dye solution on the methyl orange removal efficiency. The 3 wt% Mg doped TiO2 exhibited 95 % of decolorization of Methyl Orange. X-ray photoelectron spectroscopy measurements was performed to verify the elemental composition and chemical valence states of each element. The scavenger test in photodegradation mechanism revealed that the main reactive species was superoxide species. The electron species resonance (ESR) measurement demonstrate that the synthesized sample shows the low spin state of Mg2+ in TiO2. The correlation between Mg doping on photocatalytic activity and crystal structure were studied. Theoretical calculations were performed to gain insights into the potential mechanism underlying the tuning of luminescent and photocatalytic properties of Mg-doped TiO2 nanoparticles, enabling a comprehensive discussion.

Synergistic adsorption–photocatalytic degradation of the emerging contaminant hydroxybenzotriazole by a 3D sponge-like easy separation polypyrrole/TiO2 composite

Herein, a 3D sponge-like polypyrrole/TiO2 (Ppy-TiO2) composite aerogel was developed for the first time to remove hydroxybenzotriazole (HOBt) from water. Mesoporous TiO2 was prepared via a sol–gel method, and then the Ppy-TiO2 composite hydrogel was prepared by oxidative polymerization and converted to aerogel by freeze-drying. The morphological, compositional, and surface characteristics of the prepared materials were detailly characterized. The characterization studies revealed that pure anatase mesoporous TiO2 nanoparticles were successfully prepared and incorporated into amorphous 3D Ppy with a porous chain-like network structure. Coupling Ppy and TiO2 extended the light absorption to the visible region and decreased the electron/hole recombination rate. The performance studies revealed that the Ppy-TiO2 composite has higher adsorption and photocatalytic activities than the sum of the individual components. Optimum performance was obtained at pH 5.3 using 0.25 g/L of the Ppy-TiO2 composite with a Ppy: TiO2 mass ratio of 1:1. The intermolecular hydrogen bonding was pivotal in the adsorption process which was multilayer. The degradation of HOBt occurs primarily by holes, then superoxide anion radicals. The total organic carbon (TOC) analysis showed a 90% reduction in carbon content after 30 min of treatment. The toxicity study indicated that the photocatalytic process decreased the toxicity of the HOBt solution. The synergism between adsorption and photocatalysis, easy separation, and reusability promote the application of Ppy-TiO2 composite aerogel for water treatment.

Structural analysis of green synthesized Fe doped TiO2 nanocomposites and their application to wastewater remediation

Pure and Fe-doped TiO2 nanoparticles were synthesized through green synthesis route for wastewater remediation application. Pure and Fe-doped TiO2 nanoparticles were further characterised through various techniques like XRD, SEM, and EDS. The XRD patterns indicate pure anatase phase with space group I 41/a m d through the Rietveld refinement. The average crystalline size of Fe-doped TiO2 nanoparticles decreases with the increment in the concentration of doping. The high agglomeration of pure and Fe-doped TiO2 nanoparticles is observed through SEM. EDS analysis conforms the presence of Fe, Ti, and O elements in the nanoparticles. The photo catalytic activities of pure and Fe-doped TiO2 under ultraviolet (UV) light with different concentration were investigated. The dissolved oxygen in the water increases with the increment of Fe doping and time of exposer of UV light.

Investigation of the Effect of TiO2 Nanoparticles on Engine Performance and Emission Characteristics in Diesel Engines

This study aimed to examine the changes in performance and emission values in a four-stroke and three-cylinder diesel engine by using pure diesel fuel and fuels created by adding TiO2 nanoparticles. Adding TiO2 nanoparticles to the fuel aimed to improve the combustion characteristics of the diesel engine and reduce the harmful effects of exhaust emissions. Pure diesel and TiO2 nanoparticle added fuel samples in three distinct amounts, 25 ppm, 50 ppm, and 75 ppm, were prepared in magnetic and ultrasonic mixers as D100, D100+25TiO2, D100+50TiO2, and D100+75TiO2. All fuel samples used in the research were tested at a constant speed of 1800 revolutions per minute (rpm) at 25%, 50%, 75%, and 100% full loads. When TiO2-added fuels were compared to pure diesel, there was a 15.12% rise in brake thermal efficiency at %25 load and a 13.36% drop in brake specification fuel consumption at %25 load. EGT values also increased with the increase in load and adding TİO2. The amount of CO2 in exhaust emissions increased by 5% at maximum load in the fuel with the highest TiO2 additive according to neat diesel. There was an average increase of 11.44% in NOX emissions for all loads with TiO2 addition. The results show that the fuel mixture created by adding TiO2 nanoparticles can be used in certain proportions in diesel engines and that the TiO2 addition positively improves the combustion properties, engine performance, and exhaust gas emissions.

Characterization and comparison of titanium dioxide nanoparticles prepared by microwave and pulse laser ablation liquid methods

This study synthesized titanium dioxide (TiO2) quickly and cheaply using microwaves and pulsed laser ablation. Titanium isopropoxide (Ti[OCH(CH3)2]4) was the precursor and deionized water (DIW) was the solvent and reducer for sub-micrometer particle production in microwave technique. TiO2 nanoparticles were synthesized in pulsed laser ablation liquid medium after a 5-minute preparation period in a 1200 W commercial microwave and a 1-hour annealing at 400°C. A Q-switched Nd:YAG laser with 480 mJ energy per pulse was used for 100, 200, and 300 pulses. Multiple methods, including XRD, BET, and EDX. XRD showed anatase TiO2 in microwave-synthesised nanoparticles. Pulsed laser ablation produced pure TiO2 nanoparticles with a brookite crystalline structure. In microwave BET analysis, TiO2 has a large surface area of 72.727 to 108.28 m2/g. BET analysis indicated 82.44 to 98.67 m2/g of TiO2 surface area by pulsed laser ablation. Strong titanium (Ti) and oxygen (O) peaks in microwave and pulsed laser ablation EDX tests showed nanoparticle purity.

Investigate the biological activities of Lawsonia inermis extract synthesized from TiO2 doped graphene oxide nanoparticles.

Nanoparticles of titanium dioxide (TiO2) were made by reacting graphene oxide (GO) with Lawsonia inermis leaf extract. X-ray diffraction (XRD) analysis revealed crystalline TiO2 doped GO nanoparticles composed of a variety of anatase phases. Initially, UV-vis spectroscopy was performed to confirm the biogenesis of TiO2 doped GO nanoparticles (NP's). Using SEM, the research showed that the biosynthesized TiO2 nanoparticles were mostly spherical, polydispersed, and of a nanoscale size. Because of the energy dispersive X-ray spectroscopy (EDS) pattern, distinct and robust peaks of titanium (Ti) and oxygen (O) were observed, which were supportive of the formation of TiO2 nanoparticles. By using fourier transform infrared (FTIR) spectroscopy, it was demonstrated that terpenoids, flavonoids, and proteins are involved in the biosynthesis and production of TiO2 doped GO nanoparticles. 2,2-diphenylpicrylhydrazyl (DPPH) assays were conducted to evaluate the free radical scavenging activity of TiO2 doped GO nanoparticles. Additionally, the TiO2 doped GO NPs had enhanced antioxidant activity when compared with the TiO2 matrix. A series of pure TiO2 and TiO2 doped GO nanoparticles (5, 10, 50, and 100 mg/mL) solutions were investigated for their antibacterial activities. In the current study, zebrafish embryos exposed to pure TiO2 and TiO2 doped GO nanoparticles were toxic and suffered a low survival rate based on concentration. During photocatalysis, O2˙ and ˙OH radicals are rapidly produced because of the reactive species trapping experiment. It was estimated that pure TiO2 nanoparticles and those doped with GO were 80% effective in degrading methyl orange(MO) after 120 min, respectively. RESEARCH HIGHLIGHTS: The UV-vis absorption spectra showed a maximum absorbance peak at 290 nm. SEM, the pure TiO2 doped GO NPs exhibit agglomeration and spherical shape. When tested in zebrafish embryos, TiO2 NPs are toxic at high concentrations. GO nanoparticles showed better antioxidant activity. NPs exhibited concentration dependent antioxidative activity.

Basic magnesium sulfate@TiO2 composite for efficient adsorption and photocatalytic degradation of 4-dodecylmorpholine in brine

More than 70% of the potash fertilizer globally is produced by the froth flotation process, in which 4-dodecylmorpholine (DMP) serves as a reverse flotation agent. As the potash fertilizer production rapidly rises, the increased DMP levels in discharged brine pose a threat to the production of high-value chemicals. In this paper, composite particles of basic magnesium sulfate@TiO2 (BMS@TiO2) were prepared using a simple and mild loading method. These particles were utilized for the adsorption and photocatalytic degradation of DMP in brine. Compared with normal powdered materials, the granular BMS@TiO2 in this study can be easily separated from liquid, and the degradation intermediates will not enter the brine without causing secondary pollution. BMS@TiO2 consists of 5·1·7 phase (5Mg(OH)2·MgSO4·7H2O) whisker clusters embedding 2.3% TiO2. The adsorption equilibrium of DMP on BMS@TiO2 particles was achieved through hydrogen bonding and pore interception with the adsorption capacity of approximately 5 mg g−1 after 6 h. The photodegradation efficiency of DMP adsorbed on BMS@TiO2 reached about 92% within 16 h, which is compared with that of pure TiO2 nanoparticles. Additionally, excellent stability and recyclability of BMS@TiO2 were also observed in five cycle tests of adsorption and photocatalytic degradation of DMP, and the possible photocatalytic degradation pathways and mechanism of DMP are proposed following molecular electrostatic potential analysis. This work provides a sustainable and environmentally friendly approach for eliminating organic micropollutants from water environments.

Study of the Structural and Optical Properties of the TiO2:Au Nanocomposite Mixture Prepared by Laser Ablation Method

In this study, TiO2, Au, and a mixture of TiO2: Au nanoparticles (NPs) were produced using a Nd: YAG pulsed laser. X-Ray diffraction (XRD), Transmission electron microscopy, and Ultraviolet–visible spectroscopy (UV) was used to characterize the produced nanoparticles. The XRD patterns of TiO2 NP showed that the diffraction peaks values were corresponded to the ICDD card number (21-1272) for the anatase form of TiO2 NPs. The XRD patterns of Au NPs values were corresponded to the ICDD card number (00-004-0784) of Au NPs. The XRD patterns the mixture TiO2: Au nanoparticle with mixing ratios (4:1, 3:2 and 2.5:2.5), it was found that the diffraction peaks were (2θ~ 38.138° and 64.687°) of TiO2 nano-particles, and the diffraction peaks were (2θ~ 44.341° and 77.577° ) Au NPs. The average crystalline size of the prepared nanoparticles was determined by Scherer's technique, it was found that the average crystalline size (TiO2 NPs) is (23.36 nm), whereas mixing titanium oxide with gold nanoparticles (TiO2: Au) increased the average crystallite size to (34.18, 34.15, and 34.20 nm) for the mixing ratios (4:1, 3:2, and 2.5:2.5), respectively. The TEM images showed that the TiO2 NPs are light grey in the combination of (TiO2: Au) NPs, while for the ratio (4-1), the Au NPs are dark, spherical spheres. However, when the ratio of Au particles is increased to (2:3), the TiO2 particles remain light grey but are smaller in size. The absorption spectra of pure TiO2 NPs is in the UV spectrum, whereas the absorption spectrum of the (TiO2: Au) mixture shifts towards the wavelengths of visible light in the range (520-540 nm), according to the optical characteristics of TiO2 NPs and a mixture of (TiO2:Au) NPs. The optical energy gap of pure TiO2 NPs is 3.22eV, and it decreases as the proportion of gold nanoparticles in the mixture increases.

Structural and optical properties of Mg doped TiO2 nanoparticles synthesized by sol-gel method

Pure and doped titanium oxide (TiO2) nanoparticles with various atomic wt% (0 %, 3 %, 5 % and 7 %) of Mg were prepared by sol-gel method followed by the calcination at 100 °C for 12 h to investigate structural, optical and photoluminescence properties of TiO2 nanoparticles. Subsequently prepared samples annealed at 400 °C for 2 h for crystallization. Eventually, as prepared samples have been characterized using X ray diffractometer, scanning electron microscopy (SEM), Fourier transform Infrared Spectroscopy (FTIR), UV–Visible spectroscopy and Photoluminescence spectroscopy. XRD analysis shows that, prepared samples are crystalline in nature with exhibit of mixed phase (Rutile and Anatase) of TiO2. The crystallite size obtained around 12.0 nm of pure TiO2 nanoparticles. As increase in the doping concentration crystallite size was reduced to 6.76 nm. SEM images demonstrate the uniform growth of nanoparticles. Doping offering the tuning the energy band gap of TiO2. Photoluminescence spectra observed near UV to visible region. The intensity of Photoluminescence emission enhanced with increase of Mg doping at various concentration. Band gap and photoluminescence emission properties of doped TiO2, can be useful for optoelectronic applications and as Photo catalyst. The possible mechanism of coordination for different properties for TiO2 nanoparticles with various doping concentration have been well discussed.

Enhanced Photocatalytic Activity of Metal‐Metal‐Nonmetal Multidoped TiO2 Nanoparticles towards Visible Light

AbstractTiO2 is the most important and remarkable material in photocatalytic applications. In the present work, pure and doped TiO2 nanoparticles were fabricated by the sol‐gel synthesis route. The impact of the metal and nonmetal dopants on the performance of the photocatalysts was examined systematically. X‐ray diffraction (XRD) analysis affirmed the existence of anatase and rutile phases in the fabricated nanoparticles. The diffuse reflectance spectroscopy (DRS) analysis confirmed that all doped TiO2 nanoparticles have a lower bandgap than undoped TiO2, and (N, Cu, Ag)‐doped TiO2 nanoparticles having the lowest bandgap (2.38 eV), demonstrating that metal‐metal‐nonmetal multidoping improves TiO2′s sensitivity towards visible light. In comparison to pure and other doped TiO2 nanoparticles, methylene blue (MB) photodegrades at a faster rate (rate constant of 0.04878 min−1) with the highest photocatalytic activity (99.61 % MB degradation) on the surface of (N, Cu, Ag)‐doped TiO2. The photocatalytic activities of TiO2 nanoparticles have been improved by multidoping in the following sequence: TiO2<N‐doped TiO2<(N, Cu)‐doped TiO2<(N, Ag)‐doped TiO2<(N, Cu, Ag)‐doped TiO2.

A Spike-like Self-Assembly of Polyaspartamide Integrated with Functionalized Nanoparticles.

The integration of nanoparticles (NPs) into molecular self-assemblies has been extensively studied with the aim of building well-defined, ordered structures which exhibit advanced properties and performances. This study demonstrates a novel strategy for the preparation of a spike-like self-assembly designed to enhance UV blocking. Poly(2-hydroxyethyl aspartamide) (PHEA) substituted with octadecyl chains and menthyl anthranilate (C18-M-PHEA) was successfully synthesized by varying the number of grafted groups to control their morphology and UV absorption. The in situ incorporation of polymerized rod-like TiO2 within the C18-M-PHEA self-aggregates generated spike-like self-assemblies (TiO2@C18-M-PHEA) with a chestnut burr structure in aqueous solution. The results showed that the spike-like self-assemblies integrated with TiO2 NPs exhibited a nine-fold increase in UV protection by simultaneous UV absorption and scattering compared with the pure TiO2 NPs formed via a bulk mixing process. This work provides a novel method for UV protection using self-assembling poly(amino acid)s derivatives integrated with functional nanoparticles to tune their morphology and organization.

Synthesis of TiO2/Fe2O3 Nanocomposites as Photocatalyst for Methyl Orange Degradation

Fe2O3/TiO2 composites were successfully synthesized using the sol-gel method. The photocatalytic performance of prepared nanocomposites to degrade methyl orange under UV light irradiation was systematically investigated. The Fe2O3 added and calcination temperature were varied to study their effect on psychochemical properties. Further, to study the effect of psychochemical properties of the prepared nanocomposites on photocatalytic activity, X-ray diffraction (XRD), and scanning electron microscope Energy Dispersive X-ray spectroscopy (SEM-EDS) characterization were conducted. The visible light active Fe2O3 photocatalyst managed to decrease the bandgap energy of the prepared composites from 3.32 eV to 1.95 eV. This decrease in the band gap energy led to the composite being more active under visible light and less active under UV light irradiation. A composite with 6% Fe2O3 content exhibits the smallest degradation efficiency of 14% in 180 min, while the pure TiO2 nanoparticles are 94%. The results in this study provided important implications for further research on the preparation of composite TiO2 with Fe2O3 co-catalyst showing a promising route for improving the visible light activity of photocatalysts.

Synthesis and characterizations of molybdenum-doped titanium dioxide nanoparticles for photocatalytic removal of chromium (VI) from aqueous solutions

The photocatalytic removal of toxic heavy metals using titanium dioxide nanoparticles is an emerging technology for environmental remediation. Pure and Mo-doped TiO2 nanoparticles were synthesized using a modified sol-gel process, and then characterized by field emission scanning electron microscopy (FE-SEM) and particle size analysis (PSA) to determine their morphology and size, while X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) were used to determine their crystalline phase and composition. Brunauer–Emmett–Teller (BET) analysis was used to measure the surface area and porosity of the synthesized catalysts applying Langmuir and BET models. The catalyst was mainly composed of spherical anatase TiO2 particles, with a diameter in the range of 15–75 nm, and the maximum doping percentage of Mo was 3.3%. The Langmuir surface area of pure and Mo-doped TiO2was 91.63 and 128.73 m2/g, and the average pore volume was 0.029 and 0.032 cm3/g, respectively. The nanomaterials were used in the photocatalytic removal of Cr(VI) from aqueous solutions, and the adsorption isotherms indicated that the catalyst uptake (qe,max) amounts for Mo-doped TiO2 and pure TiO2 were 12.5 and 6.5 mg/L, respectively. Moreover, the equilibrium removal percentage was improved from 41% for pure TiO2 to 90% for Mo-doped TiO2, which confirms that photocatalytic activity is enhanced by doping TiO2 with molybdenum.

Photocatalytic Efficacy and Degradation Kinetics of Chitosan-Loaded Ce-TiO2 Nanocomposite towards for Rhodamine B Dye

The recent advancement in the production of nanomaterials with novel architectures and functionality has allowed for the effective treatment of industrial wastewaters and contaminated soil and, in that view, the current study aimed to investigate the catalytic efficacy of biopolymer-loaded titanium nanocomposite. Therefore, Cerium (Ce)-titanium dioxide (TiO2) loaded chitosan nanocomposite was formed and studied its catalytic efficacy towards the degradation of an industrial dye pollutant. For the production of Ce-TiO2/chitosan nanocomposite, we followed the hydrothermal synthesis route and the formed nanocomposite was thoroughly analyzed for the crystallinity (using powdered X-ray diffraction, XRD), surface bonding, and nature (using Fourier transform infrared, FTIR spectroscopy), morphology (scanning electron microscopy, SEM), elemental composition (electron diffraction analysis by X-rays, EDAX), porosity (Brunauer–Emmett–Teller, BET), and particles size in powdered form (transmission electron microscopy, TEM). Then the efficiency of synthesized nanocomposite was tested towards the photocatalytic degradation of Rhodamine B (Rh B) dye by applying various parameters such as the irradiation time, solution pH, catalyst dosage, and the dye concentration. Further, the Langmuir–Hinshelwood model was employed to investigate the kinetics of RhB degradation and provided a conceivable photocatalytic mechanism. It was indicated based on the catalyst mechanism that the modification of TiO2 nanoparticles with Ce and loading onto chitosan biopolymer may have accelerated the photocurrent transport due to an increase in the number of electrons and holes generated by the photon’s irradiation. In this way, the study has witnessed the excellent photocatalytic performance of Ce-TiO2/chitosan with 95% Rh B degradation as against the pure TiO2 nanoparticles thus stressing the importance of developing novel composite photocatalysts.

Ultrahigh-acetone-sensitivity sensor based on Pt-loaded TiO2 porous nanoparticles synthesized via a facile hydrothermal method

A simple hydrothermal method based on an orthogonal experimental design was used to synthesis Pt-loaded TiO2 mesoporous nanoparticles in one step. The successful synthesis of Pt-loaded TiO2 nanoparticles was demonstrated by various characterization methods. The effects of the modification of Pt and its explanation are described in detail by means of the test results. Through systematic gas-sensing tests, we found that the Pt-loaded TiO2 nanoparticles outperform pure TiO2 nanoparticles, with a high response value (S = 42.5) to 200 ppm acetone at 260 °C and with a film thickness of 0.45 mm, far superior to that of pure TiO2. The response time (8 s) and recovery time (11 s) of the material are also relatively good with excellent selectivity and long-term stability (30 days). The frequent use of acetone as an organic solution in factories and laboratories, as well as the possibility of making a preliminary diagnosis of diabetes by detecting acetone levels in exhaled gas, make this work promising for environmental monitoring and medical diagnosis.

Defect mediated magnetism in Pr/TiO2- reduced graphene oxide nanocomposites

Synthesis and characterization of Pr/TiO2 nanoparticles with its reduced graphene oxide nanocomposites by sol-gel and hydrothermal reaction and its magnetic properties is presented. X ray Diffraction and Raman analysis confirms the anatase phase structure in both nanoparticles and composites with Pr doping hindering the crystallite growth. Field Emission Scanning Electron Microscope and High Resolution Transmission Electron Microscope analysis confirm unambiguously the attachment of TiO2 spherical nanoparticles onto the graphene sheets forming an intimate interfacial contact between the particle and sheets enabling electron charge transfers. Difference in surface areas and surface energies give rise to variable emission intensity of the samples. Pr/TiO2 nanocomposites exhibit an increased bandgap values than their nanoparticles. Both Photoluminescence and Electron Paramagnetic Resonance spectroscopy confirm an increase in defect structure with increase of Pr doping. Magnetization studies show weak ferromagnetic ordering for pure TiO2 nanoparticles. The soft magnetic behaviour of the synthesised materials is useful in fabricating memory based devices.

Development of a low-cost photocatalytic aerogel based on cellulose, carbon nanotubes, and TiO2 nanoparticles for the degradation of organic dyes

A hybrid ultra-light and porous cellulose aerogel was prepared by extracting cellulose fibers from white paper, alkali/urea as a crosslinker agent, and functionalized with CNTs and pure anatase TiO2 nanoparticles. Since CNTs work as mechanical reinforcement for aerogels, physical and mechanical properties were measured. Besides, since TiO2 acts as a photocatalyst for degrading dyes (rhodamine B and methylene blue), UV–Vis spectroscopy under UV light, visible light, and darkroom was used to evaluate the degradation process. XRD, FTIR, and TGA were employed to characterize the structural and thermal properties of the composite. The nanostructured solid network of aerogels was visualized in SEM microscopy confirming the structural uniformity of cellulose and TiO2-CNTs onto fibers. Moreover, CLSM was used to study the nano-porous network distribution of cellulose fibers and porosity, and the functionalization process in a detailed way. Finally, the photocatalytic activity of aerogels was evaluated by degradation of dye aqueous solutions, with the best photocatalytic removal (>97 %) occurring after 110 min of UV irradiation. In addition, HPLC-MS facilitated the proposed mechanism for the degradation of dyes. These results confirm that cellulose aerogels coupled with nanomaterials enable the creation of economic support to reduce water pollution with higher decontamination rates.

Novel gamma-ray enhanced TiO2 nanoparticles photoanode for efficient photoelectrochemical (PEC) water splitting

The photocatalytic activity of TiO2 nanoparticles (TiO2NPs) for Hydrogen Evolution Reduction (HER) was significantly enhanced through a multi-step process involving oxygen-doping with γ-ray irradiation treatment (ranging from 10 kGy to 100 kGy), methanolic dispersion, and post-annealing temperatures. Remarkably, γ rays induced oxygen-doping, leading to improved electronic properties and chemical bonding, as demonstrated in the XPS section, which ultimately contributed to the exceptional stability of the photoanode. The resulting higher crystallinity and larger crystallite sizes, evident in Raman and XRD spectra, further enhanced the structure of the TiO2NPs. Upon γ irradiation, the deposited TiO2NPs exhibited enlargement and agglomeration, which promoted enhanced surface area, catalytic sites, and light absorption when used as a photoanode in PEC cells. The post-irradiation conditions caused a reduction in the energy band gap, resulting in a quenching effect from 3.25 eV to 3.18 eV. Intriguingly, PL analysis showed that the radiated photoanode displayed a remarkable reduction in the energetic separation of photo-generated electron-hole pairs, accompanied by a simultaneous decrease in carrier recombination. Overall, the 70 kGy TiO2NP photoanode demonstrated exceptional photostability and significantly outperformed the pure TiO2NP counterpart by increasing the photocurrent density by over 300%, reaching approximately 100.12 μA cm−2 at 1.23 vs. RHE, compared to 36.42 μA cm−2 for the pure TiO2NP. These findings underscore the significance of gamma irradiation in the field of nanomaterials and its promising potential for photoelectrochemical (PEC) solar water splitting applications.

Investigational, computational explorations on betanin, lycopene, cyanidin, and peonidin organic photo sensitizers for green energy harvesting

In keeping green energy harvesting as a prime priority and lowering the cost per watt, three potential red-colored organic photosensitizers were separated and employed for proficient titanium dioxide (TiO2) photoanodes. In a prime attempt, Rivina Humilis fruit extract (Betanin) was used for natural dye-sensitized solar cells (NDSSCs). The Prunus cerasus fruits and Solanum lycopersicum fruits (Lycopene) extracts were also successfully employed to fabricate NDSSCs. Cyanidin, Peonidin, and Lycopene are the prominent colorants existent in Prunus cerasus, and their optimized molecular structure was premeditated via Density functional theory. Their thermochemistry and associated physical parameters, Frontier molecular orbitals (FMOs) analyses, theoretical ultraviolet (UV) – visible exploration, and molecular electrostatic potential reactivity analysis were studied. Microwave-assisted sol–gel practice has yielded pure anatase TiO2 nanoparticles (NPs). The pure, red dye-sensitized TiO2 NPs endured needed studies. Environment-friendly, cost-per-watt effective NDSSCs were accomplished by expanding three red-colored organic photoanodes. Among three photosensitizers, Rivina Humilis fruits showed 1.35%, followed by Prunus cerasus at 1.27 % and slightest by Solanum lycopersicum at 0.82%. And, owing to the above performances, these NDSSCs have the potential to be employed in low-power indoor energy harvesting.

Multi-antibiotics removal under UV-A light using sol-gel prepared TiO2: Central composite design, effect of persulfate addition and degradation pathway study

The removal of three antibiotics i.e., metronidazole (MNZ), ciprofloxacin (CIP) and tetracycline (TET), from aqueous system via TiO2 photocatalysis under UV-A light was investigated. Photocatalyst(s) were prepared using sol-gel method under different calcination temperatures (400–800 °C) and water-alcohol ratio. The spherical shaped catalyst (mean particle size ∼ 61 nm) was characterized via FTIR, XRD, BET, SEM, Raman, XPS, UV-DRS, and Fluorometry, and point of zero charge was also determined (pHPZC ∼ 6.6). Batch photo-catalytic degradation studies have shown complete degradation of MNZ, CIP and TET after 50, 75 and 20 min with a TOC removal of 37%, 44% and 31%, respectively. The activity of sol-gel prepared TiO2 was comparatively higher than commercially available pure anatase TiO2 nanoparticles due to lesser mean particle size. The ratio of water to alcohol in the preparation of TiO2 catalyst was found to have significant effect on antibiotic removal. Moreover, persulfate (PS) addition of 0.1 g/L amplified the pseudo-first-order removal-rate constant by 2.75, 3.3 and 1.6 times for MNZ, CIP and TET, respectively. The higher initial pH values (8 and 10) have shown the best removal efficiency for all antibiotics. Subsequently, central composite design (CCD) experiments were conducted under multi-antibiotic conditions. Near complete removal of all antibiotics were observed within 120 min. Scavenging studies revealed that hydroxyl and superoxide radicals play major roles in photo-catalytic degradation of MNZ, CIP and TET. During photocatalysis, MNZ degradation was initiated by hydroxylation reaction, CIP by piperazine ring opening by hydroxyl attack and TET by multiple hydroxylation process. Overall, TiO2 showed good efficiency at degrading multiple antibiotics and has the potential for practical application on a larger scale.