Vis PL Research Articles

Characterization, room and low temperature photoluminescence of yttrium aluminium borate activated with Sm3+ ions

In this study, the combustion method assisted by urea that is ideally suited to economic and time saving was used for the synthesizing of reddish orange emitting YAl3(BO3)4 phosphor samples doped with various Sm3+ ions (from 0.01 wt% to 7wt%). A detailed study of the structural and luminescence properties at room/low temperature of the synthesized samples was performed. XRD analysis revealed a rhombohedral structure with an R32 space group (155). The particle size was determined by the Scherrer's method to be 48 nm. The visible PL emission spectra upon excitation at 359 nm are recorded and four emission peaks around 564, 599, 646, and 707 nm with transitions 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2 and 4G5/2 → 6H11/2 are observed. Concentration quenching was mainly caused by dipole-dipole interactions between neighbouring trivalent Sm3+ ions. Through the CIE chroma coordinates (0.606, 0.382), the optimized sample (x = 0.03) demonstrates admirable luminous performance. YAl3(BO3)4:Sm3+ can be a good candidate for use as a red component for lighting applications.

A facile, green synthesis of carbon quantum dots from Polyalthia longifolia and its application for the selective detection of cadmium

Carbon quantum dots (CQDs) has received world-wide recognition for their outstanding physicochemical properties that have the ability to substitute the semiconductor quantum dots. Herein, we have developed a strategy to determine the presence of Cd2+ using CQDs as a fluorescence probe. The CQDs were synthesized from the leaves of Polyalthia longifolia (a natural source) through a one-step hydrothermal method. The CQDs obtained from Polyalthia longifolia (p-CQDs) was characterized using XRD, TEM, FTIR, Raman Spectroscopy, XPS Studies, UV–Visible spectroscopy and PL Spectroscopy. The p-CQDs displayed bright red fluorescence under the UV light, with good water solubility, and appreciable photostability and a quantum yield of 22%. The p-CQDs had a quasi-spherical morphology with an average particle size of 3.33 nm. The p-CQDs showed high selectivity and sensitivity for the detection of Cd2+ with a low limit of detection of 2.4 nM and a wide linear range of 7.3 nM–12 μM. The PL intensity of the p-CQDs showed a quenching effect in presence of Cd2+ and the mechanism of quenching was validated via fluorescence lifetime decay studies. We have also studied the effectiveness of the fluorescent probe developed for Cd2+ sensing in real samples of ground water and industrial effluents.

Adsorption and photocatalytic degradation of oilfield produced water by visible-light driven superhydrophobic composite of MIL-101(Cr)/Fe3O4-SiO2: Synthesis, characterization and optimization

A visible-light driven superhydrophobic composite of MIL-101(Cr)/Fe3O4-SiO2 was synthesized via hydrothermal method. Various physicochemical techniques were employed for the characterization of the nanoparticles such as XRD, FTIR, FESEM, TEM, EDS, BET, UV–Visible DRS, PL, and pHpzc. The adsorption and photocatalytic performance of the synthesized nanoparticles were evaluated by synthetic and real oilfield produced water (OPW) treatment. The optimal loading amount of Fe3O4-SiO2 was determined by analysis tests and investigation of photocatalytic activity. The results showed that the superhydrophobic composite with 35% weight percent of Fe3O4-SiO2 exhibited the maximum removal efficiency. Effect of operational parameters such as pH, reaction time, and initial concentration of pollutants on the removal efficiency were evaluated. The chemical oxygen demand (COD) removal efficiency of synthetic oilfield produced water (SOPW) achieved 95.17% and 96.6% under visible and UV light irradiation by MIL-101(Cr)/Fe3O4-SiO2 (35%), at the optimum conditions of pH 4, photocatalyst dosage 0.5 g/L, COD initial concentration 600 mg/L, and illumination time 150 min. Moreover, the gas chromatography-mass spectroscopy (GC–MS) analysis results showed 97.7% and 99.2% removal efficiency of total petroleum hydrocarbons (TPH) for real and synthetic OPW, respectively. The results of kinetic and isotherm study showed that the kinetic data followed the pseudo-second-order and equilibrium adsorption was described by the Freundlich model. The high specific surface area, narrow bandgap energy as well as the charge carrier separation based on the Z-scheme heterostructure caused the improvement of binary composite photocatalyst features. The results demonstrated that the MIL-101(Cr)/Fe3O4-SiO2 superhydrophobic composite are promising photocatalyst in the degradation of oilfield produced water pollutants. Synergistic effect of adsorption and photocatalytic degradation of OPW help to enhance the removal performance.

Visible-Light-Active Vanadium and Copper Co-Doped gCN Nanosheets with Double Direct Z-Scheme Heterojunctions for Photocatalytic Removal of Monocrotophos Pesticide in Water

In this study, both vanadium and copper elements were anchored on graphitic carbon nitride (gCN) (denoted as V/Cu/gCN) via a thermal decomposition process as a novel nanosheet photocatalyst for the removal of monocrotophos (MCP). The prepared nanosheet features were studied by utilizing XRD, UV–Visible absorption spectrometry, PL, FE-SEM, TEM, and XPS techniques. These analytical techniques revealed the successful formation of direct Z-scheme heterojunctions of V/Cu/gCN nanosheets. The dopant materials significantly enhanced the electron–hole separation and enhanced the removal rate of MCP as compared with bulk gCN. The investigation of effective operating conditions confirmed that a higher removal of MCP could be obtained at a doping concentration of 0.3 wt% and a catalytic dosage of 8 mg with 80 min of visible-light irradiation. The generation of various reactive radicals during the degradation process of the photocatalyst was observed using a scavenging treatment process. Additionally, the scavenging process confirmed that e−, OH•, h+, and O2•− played a major role in MCP degradation. The direct Z-scheme dual-heterojunction mechanism, as well as the possible pathway for the fragmentation of MCP by the V/Cu/gCN nanosheet photocatalyst, was derived in detail. This research article provides a novel perspective on the formation of excellent semiconductor photocatalysts, which exhibit enormous potential for environmental treatments.

Highly efficient photocatalytic activity of visible-light-driven Mn2O3/WO3 nanocomposite

In this work, Mn2O3/WO3 photocatalysts were fabricated via a co-precipitation method for enhanced photocatalytic activity. PXRD, FTIR, UV–visible spectroscopy, PL, FE-SEM and BET analysis have been used to characterize crystallinity, metal bonding, absorption, defect states, surface morphology and porosity properties of the materials. The as synthesized photocatalysts was evaluated by degradation of Methylene blue (MB) and Rose Bengal (RB) dyes under simulated visible-light irradiation. The Mn2O3/WO3 heterostructure's enhanced surface area, better light absorption, and efficient photogenerated carrier separation resulted in improved catalytic performance. Almost 80% photocatalytic degradation of MB and RB has been observed within 120 min.

Boosted visible-light-driven photocatalytic degradation of lomefloxacin over α-Ag2WO4/NiSx nanocomposites

In this paper, α-Ag2WO4-supported NiSx co-catalyst has been synthesized using a hydrothermal route. The synthesized materials were characterized by XRD, FESEM, EDX, UV–visible DRS, PL, ICP-OES and BET surface area tests. The prepared α-Ag2WO4/NiSx nanocomposite has efficient photocatalytic degradation effects toward environmental pharmaceutical contaminants (lomefloxacin, LOM) under visible light. The max photocatalytic degradation efficiency over 0.1 g/l dose of α-Ag2WO4/10%wt-NiSx sample was 98.4% within 60 min at pH 6.1 (unmodified), which is 4.5 and 11.4 times higher than that of bare α-Ag2WO4 and NiSx, respectively. The enhanced photocatalytic activity of the nanocomposites was attributed to efficiently separation of the charge carriers and their increased visible-light harvesting ability. Reactive species scavenging tests were conducted to evaluate the role of each species. Moreover, the possible photocatalytic degradation mechanism was suggested. Finally, there was no significant loss in the photocatalytic degradation activity after using α-Ag2WO4/10%wt-NiSx photocatalyst five reaction cycles.

Solar light-responsive α-Fe2O3/CdS/g-C3N4 ternary photocatalyst for photocatalytic hydrogen production and photodegradation of methylene blue

Photocatalytic degradation of waste materials in aqueous solutions, as well as photocatalytic hydrogen generation, were investigated for remediation of environment and renewable energy production. α-Fe 2 O 3 and CdS are attractive visible-light-driven semiconductor photocatalysts because of their inexpensive cost, simple production methods, and stability. Whereas, its implementations were limited by the photocorrosion, narrow optical band gap for solar-light operations and poor separation of photogenerated electron-hole pair. To increase the performance of α-Fe 2 O 3 , CdS, α-Fe 2 O 3 /CdS, and g-C 3 N 4 ; a ternary nanocomposite (α-Fe 2 O 3 /CdS/g-C 3 N 4 ) was designed. To obtain binary structure, CdS nanoparticles were overgrown on α-Fe 2 O 3 nanorods-cubes using a simple wet-chemical process, and as-prepared g-C 3 N 4 was decorated with binary composite. XRD, SEM, XPS, BET, UV–Visible spectrometry, FT-IR, PL and EIS were employed to investigate the crystal structures, surface morphology, optical properties, functional groups and electrochemical characteristics. Considering the optical absorption properties, the photocatalytic studies were performed for hydrogen production and MB dye degradation under solar light irradiation. Among the synthesized semiconductors, the ternary material had the highest photocatalytic hydrogen evolution, 165 µmol g −1 2 h −1 from water. Within 120 min, the photocatalytic performance resulted in 99.4% degradation of the MB. The higher activities were attributed to Z-scheme mechanism, optical band levels and strict heterojunctions of the photocatalysts that induces an influential electron-hole separation, subsequently rapid diffusion of photogenerated charge between components and also the optical bandgap value of the ternary structure that more convenient for solar lights applications. This work paves a way for improvement of photocatalysts working in practical conditions of pollution and energy issues. • The α-Fe 2 O 3 /CdS/g-C 3 N 4 ternary heterostructured material was synthesized. • Photocatalytic hydrogen production was studied. • Photocatalytic degradation was studied. • The α-Fe 2 O 3 /CdS/g-C 3 N 4 ternary nanocomposite showed best photocatalytic properties under solar light irradiation.

Morphological guided sphere to dendrite BiVO4 for highly efficient organic pollutant removal and photoelectrochemical performance under solar light

Monoclinic BiVO4 (m-BiVO4) has been reported as promising phase for solar light driven photocatalysis. However, in the case of morphology guided BiVO4 with different synthetic conditions maintaining the m-BiVO4 phase remains a substantial challenge for achieving an efficient photocatalyst driven by solar light. Herein, a simple hydrothermal approach was used to produce well-defined template free m-BiVO4 dendrites with distinct branches for photo catalytically removal of organic pollutant and photocurrent generation. The development of monoclinic dendrite BiVO4 was confirmed after comprehensive structural, morphological, and optical examinations. FE-SEM images of m-BiVO4 revealed transformation of spherical to dendritic morphology with distinct branches by simply changing the HNO3 to NaOH ratios from 2:1 to 2:2, which are named as BVO 2-1 and BVO 2-2, respectively. The BVO 2-2 dendrites exhibited improved activity of 98% towards methylene blue (MB) photodegradation upon simulated solar light irradiation. The BVO 2-2 dendrites photoelectrode showed an outstanding photocurrent density of 1.4245 mAcm−2 than that of the BVO 2-1 spherical photoelectrode (0.7367 mAcm−2). Enhanced photocatalytic and photoelectrochemical action, could be ascribed to the unique morphological changes provides photoactive sites, harvest more light utilization together with higher separation of e−/h+ pairs. Furthermore, photocatalytic mechanism is investigated based on scavenger trapping agent, valence band XPS, UV Visible DRS and PL study. Our findings could pave the way for the development of dendritic nanostructure photocatalysts with improved photocatalytic activity.

Graphitic carbon nitride embedded Ni3(VO4)2/ZnCr2O4 Z-scheme photocatalyst for efficient degradation of p-chlorophenol and 5-fluorouracil, and genotoxic evaluation in Allium cepa

Visible light photocatalysis using nano heterostructures offers an eco-friendly alternative for the removal of organic molecules. Here, we reported an enhanced photocatalytic activity of g-C3N4/Ni3(VO4)2/ZnCr2O4, a dual Z-scheme nano-heterojunction for the photocatalytic removal of p-chlorophenol (p-CP) and 5-fluorouracil (5-FU). The nano heterojunction was fabricated by a facile co-precipitation method. Initially, the fabricated nanocomposites (NCs) were characterized for Physico-chemical and optoelectronic properties, by XRD, XPS, SEM, TEM, UV–Visible DRS, BET, PL, and EIS. The fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 has shown excellent photocatalytic activity. The complete mineralization of both p-CP and 5-FU observed after 160 and 200 min of visible light irradiation respectively. The mineralization of p-CP and 5-FU was confirmed by total organic carbon (TOC) estimation and the percentage of removal TOC for p-CP and 5-FU was 99.25% and 98.9% respectively. The stability of the particle was confirmed by six cycles test. The reusable efficiency of the NCs was found to be 99.7% after six consequent cycles. The stability of the NCs was confirmed by XRD and XPS analysis of reused photocatalyst. The scavengers assay and ESR analysis confirmed the major role of •OH radicals in enhanced photocatalytic activity. The degradation pathway of p-CP and 5-FU was determined by GC–MS/MS and the possible toxicity of the intermediate compounds was determined by the ECOSAR program, which shows the non-toxic nature of the end product on green algae, daphnia, and fish. The toxicity of the NCs was tested against Allium cepa which further confirm the non-toxic nature of NCs. The study suggests that fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 NCs can be utilized for environmental remediation applications.

The effect of co-dopants (Cu3+, Sm3+-ions) on the optical properties of Sodium-Zinc-Borate glasses

In this article, we describe the synthesis and optical characteristics of (Cu2+, Sm3+-ions) doped sodium zinc borate glasses made using the conventional melt quenching technique. The produced glasses were investigated using XRD, UV-Visible-NIR, and Photoluminescence spectroscopy. XRD analysis reveals the amorphous nature of produced glass samples. The presence of both Cu2+ and Sm3+ ions may be seen in UV-Visible-NIR absorption spectra in the 200-2000 nm range. Refractive index, density, and energy band gaps were all examined as physical and optical variables.In addition, photoluminescence emission spectra for two excitation wavelengths, 290 nm and 400 nm, were obtained to confirm Cu2+ and Sm3+-ions-induced photoluminescence in sodium zinc borate glasses, respectively. When using a 290 nm excitation, the spectra exhibited one wide emission peak about 460 nm, however when using a 400 nm excitation, the spectra revealed three separate peaks in the visible region.The spectral properties of all of the samples were identical. The drop in PL intensity with Sm3+ concentration might be attributed to energy transfer between copper and samarium ions with 400 nm excitation. Surprisingly, the glass sample with 1 mol% Sm3+ exhibits the highest visible PL intensity / emission. The investigation’s findings show that the produced samples are viable candidates for photonic and LED applications.

Variation of sulfur concentration on the effective deposition of solution processed ZnS thin films for buffer layer in thin film solar cells

The influence of sulfur concentrations on the growth of ZnS thin films were investigated by low cost chemical spray pyrolysis and chemical bath deposition techniques. The deposited ZnS films showed the major peaks at (111) zinc blende structure from X-ray-diffraction. The FESEM analysis resulted that the deposited films were identified as sphere-like particles for both deposition techniques and the ZnS particle size improved as the sulfur concentration increased in the prepared solutions. The UV analysis showed higher optical transmittance > 70% in the visible region and PL spectra exhibited the defects-free ZnS peaks at blue-green emission bands in the range between 350 nm and 550 nm by both deposition methods. The linear response of I-V characteristics denote to ohmic behavior of the deposited films and the calculated resistivity of the films were in the range of 107Ω.cm and 108 Ω.cm. Hence, the characterized results suggest that the deposited ZnS films with increasing sulfur concentration using both deposition methods show optimum properties for buffer layers in thin film photovoltaics.

Characterization of thermally evaporated copper selenide thin films for device applications

Copper Selenide thin films were grown by thermal evaporation method on glass substrate. The properties of the thin films were characterized by XRD, UV–Visible spectroscopy, SEM-EDS, and PL analysis. The uniformity and stoichiometry of the deposited films were confirmed by SEM-EDS analysis. The XRD results confirmed the cubic phase with prominent (111) orientation. The deposited films showed very low transmittance (∼20%) and direct band gap of about 2.35 eV. Further, PL spectra revealed the presence of defect states present in the films. The deposited films are p-type material with carrier density of 1.14 × 1016 cm−3. Structural, spectroscopic, and electrical studies have confirmed the device quality of the grown films, which find potential application in the field of renewable energy.

CdSe QDs@ Fe-based metal organic framework composites for improved photocatalytic RhB degradation under visible light

A series of composites based on Fe-based MOF (Fe-BDC) and CdSe quantum dots (CdSe QDs) have been synthesized with CdSe QDs well-embedded into Fe-BDC particles, which are characterized by XRD, SEM, TEM, ICP-OES, FT-IR, N 2 physical sorption, UV–visible DRS, PL and electrochemical measurements. By detecting the degradation of Rhodamine B (RhB) in aqueous solution under visible light irradiation, the photocatalytic performance of CdSe@Fe-BDC nanocomposites were apparently improved by 5.8 times relative to single Fe-BDC, which can be attributed to the heterostructure formed in CdSe@Fe-BDC. Owing to the perfect interfacial contact, this promotes electron transfer from CdSe to Fe-BDC and significantly facilitates the separation of the photogenerated electron-hole pairs. The photocatalytic mechanism studied by adding sacrificial agents revealed that the predominant active species in the system is hole cation (h + ) and oxygen free radicals (•O 2 − ). A series of composites based on Fe-BDC and CdSe quantum dots have been prepared and the resultant composites show excellent photocatalytic performance in RhB degradation. • A novel CdSe@Fe-BDC nanocomposite was synthesized and characterized. • CdSe QDs were uniformly dispersed in Fe-BDC particles. • CdSe@Fe-BDC exhibited an enhanced visible-light photocatalytic degradation of RhB in water. • The mechanism for photocatalytic degradation of RhB of CdSe@Fe-BDC was proposed.

Spin-polarized room temperature ferromagnetism in co-doped ZnO synthesized by electrodeposition

We have investigated the structural, optical and magnetic properties of Zn0.90Co0.10O, synthesized by the method of two electrode electrodeposition. X-ray diffraction measurement confirms the evolution of a single-phase polycrystalline hcp Wurtzite structure. Co-2p core-level XPS confirms that Co is present in mixed 2+ and 3+ states. The Fourier Transform Infrared (FTIR) spectrum findings substantiate the fact that a single-phase Hexagonal Wurtzite ZnO Crystal Structure has evolved. The SEM micrograph of the sample reveals smooth and dispersed morphology consisting of fine particles. The U-V visible NIR and PL spectroscopy measurements substantiate the fact that Co2+ has substituted Zn2+ in the matrix of ZnO which agrees with XRD findings. The sample shows good optical property and reveals a blue shift. It seems that the material is a potential candidate to be used as UV sensors. Room Temperature Intrinsic Ferromagnetism has been confirmed by VSM measurement.

Hydrolytically stable citrate capped Fe3O4@UiO-66-NH2 MOF: A hetero-structure composite with enhanced activity towards Cr (VI) adsorption and photocatalytic H2 evolution

Design and facile fabrication of a magnetically separable hetero-structure photocatalyst as well as an adsorbent having dual green benefits towards energy conversion and pollutant remediation are quite indispensable in the current scenario. In this regard, a composite of citrate capped Fe3O4 and UiO-66-NH2 has been designed to remediate Cr (VI) by adsorption and harvest photons from visible light for clean energy (H2) conversion. The material was prepared by the union of citrate capped Fe3O4 (CCM) and versatile aqueous stable Zr-based MOF (UiO-66-NH2) through in-situ solvothermal method. The composite of CCM with MOF (MU-2) was studied through sophisticated analysis techniques; PXRD, FT-IR, BET, UV–Visible DRS, PL, TG, HRTEM and XPS etc. to reveal the inherent characteristics of the material. BET surface analysis revealed high specific surface area (572.13 m2 g−1) of MU-2 in comparison to its pristine MOF. Furthermore, the dual function composite MU-2′s VSM studies showed that its magnetic saturation is 3.07 emu g−1 that is suitable for magnetic separation after desired reaction from aqueous media. The Cr (VI) sorption studies revealed that the composite adsorbent (MU-2) showed maximum monolayer adsorption capacity (Qm) of 743 mg g−1 which followed pseudo second order kinetics. Moreover, the sorption thermodynamics revealed that the process was spontaneous and endothermic in nature. In addition to it, the synthesized composite material displayed enhanced activity towards photocatalytic H2 evolution with a maximum evolution rate of 417 µmole h−1 with an apparent conversion efficiency (ACE) of 3.12 %. Typically, MU-2 displays high adsorptions of Cr (VI) as well as some extent of Cr (VI) reduction owning to its populous active sites and free carboxylate groups respectively. Moreover, the synergistic effect of CCM and UNH in the composite resulted in Z scheme mediated charge transfer mechanism that showed enhanced H2 photo-evolution rates. Hence, MU-2 can be readily utilized as magnetically retrievable dual function composite for Cr (VI) adsorption and photocatalytic H2 evolution.

Structural, energy gap tuning, photoluminescence and magnetic properties of Sn-doped Zn0.96Ni0.04O nanostructures

Ni (4%) doped ZnO and Ni, Sn (Ni = 4% and Sn = 1 and 2%) dual doped ZnO nanostructures have been synthesized by sol-gel route. The hexagonal ZnO structure of Ni/Sn doped ZnO was not disturbed by Sn addition and no secondary or impurity phases of Ni/Sn were identified in the XRD pattern. The continuous suppression of nucleation and hence the growth rate by Sn doping reduce the grain size and the replacement of Sn4+ ions with lower ionic radius instead of Zn2+ in Zn–Ni–O lattice is also accelerate the size decrement. Hexagonal wurtzite structure was not affected by Sn substitution. The reduced size and higher transmittance at Zn0.94Ni0.04Sn0.02O is recommended for the industrial application like transparent electrode. The continuous blue shift of energy gap from 3.53 eV (Sn = 0%) to 3.75 eV (Sn = 2%) is clarified by Burstein-Moss (BM) band filling effect with the help of energy level diagram. The existence of Zn–O–Ni/Sn bonding is verified by Fourier transform infra-red examination. The improved visible PL emissions like near violet, blue and green emissions by Sn doping is due to the existence of higher oxygen vacancies and oxygen related defects in Zn–Ni–Sn–O lattice. The room temperature ferromagnetism (RTFM) with elevated saturation magnetization by Ni/Sn doping in ZnO is stimulated by the intrinsic exchange interaction between Zn/Ni/Sn ions through the defects induced by Sn.

Enhanced photoluminescence quantum yield of terbium nano-MOFs synthesized by microwave assisted solvothermal method

In the present work luminescent metal–organic frameworks consisting of terbium ions as the metallic center and 1,4 benzene-dicarboxylic acid (BDC), benzene-tricarboxylic (BTC) acid and 1,3 thiophane-dicarboxylic acid (TDC), as the organic ligands, are synthesized by the microwave assisted solvothermal method at a relatively short time. The samples are studied before and after a thermal annealing process at 400°C. The structural and chemical analysis indicate the formation of nanocrystals of about 8.8 nm, 5.0 nm and 127 nm for BDC, BTC and TDC samples, respectively. All the samples show carbon and oxygen in excess attributed probably to remnants of the N,N-Dimetilformamide used as solvent during the synthesis or to diffused particles from the atmosphere. The luminescent analysis shows a high quantum yield value for the BDC framework, 99.6%, after the annealing process, attributed to an antenna effect; whereas both the BTC and TDC samples show a higher quantum yield before annealing; 64.1% and 13.3%, respectively. The luminescence decay time is also computed in the samples resulting between 1 and 1.5 ms for both BDC and BTC samples, whereas for the TDC sample the decay time was about 0.2 ms. A noticeable daylight visible PL emission is observed in all samples.

Development of Progesterone Oily Suspension Using Moringa Oil and Neusilin US2

The objective of the present study was to screen oils and suspending agents for the formulation of novel progesterone (PGT) suspension, demonstrating improved solubility, drug release, stability, and non-allergenicity. Presumably, formulated novel PGT suspensions could supersede clinically available peanut oil and lecithin based formulations (PL). The PGT suspensions were formulated by the trituration method using a vehicle (Moringa oil/peanut oil/sesame oil/sunflower oil) and a suspending agent (Neusilin US2/Fujicalin/Lecithin/Syloid 244) separately. A total of 16 PGT suspensions were evaluated for particle size, zeta potential, sedimentation, thixotropy, stability, in vitro dissolution, and allergenicity. Indeed, in silico studies were performed to elucidate interactions between principal components of the suspension, using software V. life MDS 4. 6. Findings revealed the highest PGT solubility and high viscosity in Moringa oil-based formulations. Suspensions comprising Moringa oil and Neusilin US2 (MN) exhibited the lowest suspensiod size (48.7 nm), least sedimentation rate, highest zeta potential (− 39.8), and dilatent flow behavior. The in vitro percent cumulative PGT dissolved was significantly high (94.82 ± 2.56%) from MN vis PL (52.68 ± 2.62%), at p < 0.05. In silico studies revealed strong hydrophobic and Van der Waals interactions between PGT, Moringa oil, and Neusilin US2, compared with others. Allergenicity study confirmed the superiority of Moringa oil over peanut oil (p < 0.01). Moringa oil-based PGT formulations containing Neusilin US2 could be a better alternative to clinically available peanut oil and lecithin-based suspensions. Additionally, in silico interaction tools can be effectively employed for the prediction of stability and performance of suspensions.

Photocatalytic oxidation of tetracycline by magnetic carbon-supported TiO2 nanoparticles catalyzed peroxydisulfate: Performance, synergy and reaction mechanism studies

TiO2 decorated on ferroferric oxides coupled with activated carbon (TFOC), as a magnetic heterogeneous catalyst, was synthesized and its photocatalytic ability was assessed in coupling with UV light towards peroxydisulfate (PS) activation to degrade tetracycline (TC). Main properties of the catalyst were analyzed by using UV–visible DRS, FESEM, VSM, PL, EDS, TEM, XRD and BET techniques. A proposed reaction mechanism was suggested for activating PS and TC degradation. Both TiO2 and Fe3O4 (FO) were synthesized and dispersed successfully on the carbon surfaces in nano-sized scale. It was found that the photocatalytic activity of TiO2 was accelerated significantly after loading on the magnetic carbon. TFOC showed an excellent magnetic response in the presence of a magnet. According to PL analysis, FO nanoparticles and carbon played a critical role in the suppression of recombination of excited electrons and holes. TFOC in coupling with UV showed a best performance, compared to the other single and binary processes for TC decontamination. After 15 min reaction, the highest level of elimination, 96% TC (60 mg/L) and 72.1% TOC were obtained at optimum operational conditions: pH:5.0, TFOC: 0.3 g/L and PS:1.0 mM. A noticeable synergistic effect was found for TFOC in combination with UV and PS. Both negligible Fe leaching and high efficiency of degradation were achieved with reused times, illustrating that TFOC has an excellent durability and reusability. Based on trapping tests, the importance of involved oxidizing species during TC decontamination over TFOC/PS/UV system was in order of 1O2 > SO4•– > h+ > O2•– > HO•. Among studied anions, the highest quenching impact was observed for chloride ions. Particularly, TFOC composite showed the high catalytic activity as well excellent potential in recovery and its coupling with UV light and PS can be introduced as a promising strategy for efficient destroying TC antibiotic.

Effect of electrolyte solution and deposition methods on TiO2/CdS core–shell nanotube arrays for photoelectrocatalytic application

In this work, TiO2 nanostructure thin films were deposited by using anodization technique, while CdS thin films were deposited on TiO2 films by two methods chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR). The structure of TiO2/CdS films were investigated and analyzed by XRD, SEM, and AFM, but the optical properties were investigated by UV–visible spectroscopy, PL spectroscopy, and spectral response. XRD analysis of all deposited films has confirmed the formation of two phases one is tetragonal phase (anatase, and rutile) for TiO2, and second hexagonal phase which belong to CdS layer. SEM images of TiO2 nanotubes arrays (NTAs)/CdS showed the TiO2 NTs walls become decorated with aggregates of fine CdS nanoparticles that partly penetrate into the TiO2 NTAs pores. AFM measurements displayed increase in the surface roughness compared with TiO2 films. PL measurement results of TiO2/CdS core–shell show two peaks, one is located at UV-region pointed to energy band gap for TiO2 nano films, and second one is located at visible region pointing to recombination of photogenerated electron–hole pairs within CdS layers. Spectral response measurements showed photocurrent peaks for all TiO2/CdS films deposited with different electrolyte solution have red-shift to visible region. When illuminated with a UV–Vis light source, the TiO2/CdS core–shell films displayed high response. A higher response to UV–Vis light was attained with the use of TiO2 NTAs/CdS films prepared by anodization /CBD. This approach offers a technique for fabricating photoelectrodes.