Reflectance Difference Spectroscopy Research Articles

Identifying high-order plasmon modes in silver nanoparticle-over-mirror configuration

Metallic nanoparticle-over-mirror (NPOM) represents as a versatile plasmonic configuration for surface enhanced spectroscopy, sensing and light-emitting metasurfaces. However, experimentally identifying the high-order localized surface plasmon modes in NPOM, especially for the best plasmonic material silver, is often hindered by the small scattering cross-section of high-order plasmon modes and the poor reproducibility of the spectra across different NPOMs, resulted from the polyhedral morphology of the colloidal nanoparticles or the rough surface of deposited polycrystalline metals. In this study, we identify the high-order localized surface plasmon modes in silver NPOM by using differential reflection spectroscopy. We achieved reproducible single-particle absorption spectra by constructing uniform NPOM consisting of silver nanospheres, single-crystallized silver microplates, and a self-assembled monolayer of 1,10-decanedithiol. For comparison, silver NPOM created from typical polycrystalline films exhibits significant spectral fluctuations, even when employing template stripping methods to minimize the film roughness. Identifying high-order plasmon modes in the NPOM configuration offers a pathway to construct high-quality plasmonic substrates for applications such as colloidal metasurface, surface-enhanced Raman spectroscopy, fluorescence, or infrared absorption.

Green synthesis of highly active and recyclable chromium oxide nanocatalyst for biodiesel production from novel nonedible oil seeds

AbstractThis study explores the sustainable production of biodiesel from nonedible Phyllanthus maderaspatensis seed oil (highest oil content of 35%, FFA 0.87 mg/KOH), utilizing an innovative green synthesis approach for chromium oxide nanoparticles derived from the waste fruit parts of Aubergine for the very first time in the current work. In pursuit of alternatives to fossil fuels, our research underscores the environmental and socio‐economic benefits of biofuels, particularly in reducing greenhouse gas emissions. The optimized process yielded a 92% biodiesel conversion under conditions of a 9:1 methanol‐to‐oil ratio, 0.135 wt.% catalyst concentration, and a reaction duration of 150 min at 80°C. Comprehensive analysis techniques, including XRD, FTIR, SEM, EDX, Zeta analysis, differential reflectance spectroscopy (DRS), GC–MS, and NMR (1H, 13C), were employed to characterize the synthesized nanocatalyst and biodiesel product. The biodiesel's fuel properties, such as acid value, fire point, pour point, viscosity, kinematic density, sulfur content, and cloud point, were rigorously tested, demonstrating compliance with international standards (ASTM D‐6571, EN 14214, and GB/T 20828‐2007). The use of P. maderaspatensis seed oil, an economical and environmentally friendly feedstock, in conjunction with a cost‐effective nanocatalyst, presents a viable pathway for the sustainable and scalable production of biodiesel. This study contributes to the advancement of bioproducts for a sustainable bioeconomy by demonstrating an integrated approach to bioenergy production that leverages biotechnological innovations and addresses both environmental and socio‐economic dimensions.

Green synthesis and characterization of α-Mn2O3 nanoparticles for antibacterial activity and efficient visible-light photocatalysis

In this study, green synthesis, characterizations, photocatalytic performance, and antibacterial applications of α-Mn2O3 nanoparticles are reported. The synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscope (TEM), Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Brunauer Emmett Teller (BET), Electrochemical Impedance Spectroscopy (EIS), Photoluminescence (PL), and Differential reflectance spectroscopy (DRS) analysis. The investigation verified that the α-Mn2O3 nanoparticles possessed a cubic structure, with a crystallite size of 23 nm. The SEM and TEM techniques were used to study the nanoscale morphology of α- Mn2O3 nanoparticles, which were found to be spherical with a size of 30 nm. Moreover, the surface area was obtained as 149.9 m2 g−1 utilizing BET analysis, and the band gap was determined to be 1.98 eV by DRS analysis. The photocatalysis performance of the α-Mn2O3 NPs was evaluated for degrading Eriochrome Black T (EBT) dye under visible light and degradation efficiency was 96% in 90 min. The photodegradation mechanism of EBT dye was clarified with the use of radical scavenger agents, and the degradation pathway was confirmed through Liquid Chromatography–Mass Spectrometry (LC–MS) analysis. Additionally, the produced nanoparticles could be extracted from the solution and continued to exhibit photocatalysis even after five repeated runs under the same optimal conditions. Also, the antibacterial activity of green synthesized α-Mn2O3 nanoparticles was investigated by using the broth microdilution method towards Enterococcus faecalis ATCC 29212 (Gram-positive), Staphylococcus aureus ATCC 29213 (Gram-positive), Salmonella typhimurium ATCC 14028 (Gram-negative), Klebsiella pneumoniae ATCC 7881 (Gram-negative), Escherichia coli ATCC 25922 (Gram-negative), Proteus mirabilis ATCC 7002 (Gram-negative), and Pseudomonas aeruginosa ATCC 27853 (Gram-negative) bacterial strains.

Development of a novel Z-scheme CoxNi1−xTiO3/CdS (x = 0.5) photocatalyst for the efficient degradation of organic pollutants via a visible-light-driven photocatalytic process

Herein, for the first time, we reported the synthesis of a novel Z-scheme CoxNi1−xTiO3/CdS (x = 0.5) heterojunction photocatalyst and the investigation of its visible-light-driven photocatalytic performance toward degradation of methylene blue (MB). The developed photocatalyst was structurally characterized by applying X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), differential reflectance spectroscopy (DRS), and photoluminescence (PL) techniques. The results indicated the formation of a highly porous structure with improved visible light adsorption capacity, favorable for the catalytic activity. At an optimum condition of 10 mg/L of MB and 300 mg/L of catalyst, the ternary photocatalyst demonstrated a MB removal efficiency of 99 % after 75 min of the treatment process. The radical trapping experiments unveiled that hydroxyl and superoxide radicals were two main reactive species formed under visible light, while the valance holes possessed an insignificant role. The synergetic impact of the CoxNi1−xTiO3 (x = 0.5) and CdS on the photodegradation of MB over the as-prepared CoxNi1−xTiO3/CdS (x = 0.5) photocatalyst through Z-scheme photocatalysis was indicated by the results of the mechanism studies. The percentage impact of the treatment time, MB concentration, the ratio of CoxNi1−xTiO3/CdS (x = 0.5), and the dosage of catalyst using analysis of the CCD modeling was obtained as 47.04, 16.67, 7.22 and 0.87 %, respectively. Furthermore, the as-synthesized photocatalyst possessed high recyclability and photostability with only a 3 % decline in activity after four repetitive cycles.

Exploiting Hydrogen Interaction of Drugs and Biodegradable Scaffolds Using Nanoparticles Loaded Nanofibers

AbstractThis study presents a detailed investigation of the structural and surface modifications of Fe3O4 nanoparticles (NPs). Fourier Transform Infrared (FTIR) spectroscopy was utilized to analyze the distinct characteristic peaks of Fe3O4 NPs and their subsequent modifications with stearic acid (ST) layers. The FTIR analysis revealed characteristic peaks at 580 cm−1, and 441 cm−1, corresponding to the Fe‐O stretching vibrations of the bulk Fe3O4 NPs. The successful loading of stearic acid onto the Fe3O4 NPs was confirmed by the appearance of new peaks at 1413 cm−1 and 2908 cm−1, indicative of the asymmetric CH2 stretch and CH3 umbrella vibration modes of stearic acid. UV‐Vis spectroscopy further corroborated the efficient loading of tetracycline and ibuprofen onto Fe3O4/DST nanoparticles, as evidenced by changes in absorption spectra. N2 adsorption‐desorption isotherms illustrated the presence of micro and meso pores on the surface of Fe3O4 NPs, with alterations in pore volume and diameter post‐surface modification and drug loading. Evaluation of magnetic properties indicated a reduction in saturation magnetization after surface modification and drug loading, attributed to changes in homogeneity and surface moments. Differential Reflectance Spectroscopy (DRS) and Raman spectroscopy elucidated distinctive peaks and shifts in spectra, confirming the composition and structural changes in drug‐loaded nanofibers.

Characterization of Molybdenum (IV) Sulfide Prepared by Chemical Vapor Deposition Using Differential Reflectance Spectroscopy

Molybdenum (IV) sulfide is widely employed in electronic device applications. Recognized as one of the most efficacious methods for fabricating high-quality molybdenum (IV) sulfide, the chemical vapor deposition (CVD) method’s application necessitates the development of a straightforward, swift and nondestructive characterization tool. Thus, this paper presents a rapid and reliable differential reflectance spectroscopy (DRS) instrumentation, grounded on the optical microscope, capable of characterizing two-dimensional materials prepared by CVD. This universal nondestructive identification tool facilitates the investigation of two-dimensional materials on both opaque and transparent substrates. MoS2 samples prepared by CVD were characterized on SiO2/Si and sapphire substrate. The results indicate that the exciton absorption peak can be accurately identified, validating the instrumentation’s utility for material detection and monolayer identification. The characterization results, corroborated by the Raman spectra with a wavenumber difference of approximately 20 cm−1 and the triangular appearance of the optical image, affirm the application of this instrumentation. Ultimately, the DRS instrumentation provides a swift and nondestructive route to characterize physical properties such as bandgap and optical properties for two-dimensional materials.

Sono-photo electrocatalytic reduction of CO2 to C2+ products using a p-n heterojunction Co2SnO4/CuO supported on a three-dimensional copper foam

This work demonstrates simultaneously employing light and ultrasonic irradiation to improve the electrocatalytic reduction of CO2 on Co2SnO4/CuO/Cu foam. We have synthesized n-type Co2SnO4 nanoparticles on p-type substrate CuO/Cu foam via hydrothermal method then investigated electrocatalytic, sono-electrocatalytic, photo-electrocatalytic and sono-photo electrocatalytic responses of Co2SnO4/CuO/Cu foam in the CO2-saturated electrolyte. The UV–visible differential reflectance spectroscopy (DRS) experiment displayed that Co2SnO4/CuO/Cu foam harvests more visible light energy than CuO/Cu foam. In cyclic voltammetry (CV) investigations, the electrocatalytic response of the Co2SnO4/CuO/Cu foam occurred at a higher positive potential (ΔE = 0.46 V) than the CuO/Cu foam, andsolo application of ultrasound and light irradiation resulted in 1.3- and 1.4-fold increases in cathodic current density, respectively, while synchronized ultrasound and light irradiation resulted in a 1.8-fold increase during the electrocatalytic CO2 reaction on the Co2SnO4/CuO/Cu foam. Based on the electrochemical impedance spectroscopy (EIS) tests, the formation of p-n heterojunction on Cu foam decreased charge transfer resistance from 198.8 Ω to 48.79 Ω, and under sono-photo irradiation, charge transfer irradiation resistance on Co2SnO4/CuO/Cu foam receded to 32.96 Ω. The chronoamperometry technique followed by gas chromatography-mass spectrometry revealed acetaldehyde and propylene glycol as CO2 conversion products with a 66 % coulombic efficiency.

Magnetic Fe-doped TiO2@Fe3O4 for metronidazole degradation in aqueous solutions: Characteristics and efficacy assessment

Antibiotics present in aquatic environments can contribute to the emergence of antibiotic-resistant bacterial strains, posing potential threats to public health. Therefore, efficient strategies to remove these compounds from water systems are essential to reduce both ecological and human health risks. This research aimed to assess the photocatalytic removal efficiency of metronidazole (MET) from an aqueous solution using a 15-W bare UVC lamp and magnetic nanocatalysts (Fe-doped TiO2@Fe3O4), which were synthesized using the sol-gel technique. Furthermore, scanning electron microscopy with integrated energy dispersive X-ray analysis (SEM/EDX), X-ray diffractometry (XRD), Differential reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR) analysis were carried out to characterize the synthesized nanocatalysts. The influence of several factors, such as pH, initial MET, and nanocatalysts concentrations during reaction times of 15–120 min, was studied. The characterization results confirmed that Fe and Ti were successfully integrated into the Fe– doped TiO2@Fe3O4 nanocomposite. Highest MET degradation efficiency (99.37 %) was observed at a pH of 3, with an initial MET concentration of 60 mg/L, nanoparticle dosage of 800 mg/L, and a reaction time of 90 min. The stability of the nanocatalyst was acceptable. The results suggest that OH ions may play a crucial role in the degradation of MET demonstrating photocatalytic degradation can be an effective way to remove MET from water resources. This research sets a precedent for future endeavors aimed at harnessing photocatalysis for environmental remediation of pharmaceutical pollutants.

Efficient degradation of parathion as a pollutant and diazinon as a nerve agent by reaction mechanism with rGO-Co3O4/ZnO nanocomposite photocatalyst

Chemical warfare agents and agricultural pesticides are two of the deadliest and most nefarious pollutants that have devastating impacts on both people and the environment. In this work, the Zinc oxide-decorated cobalt oxide/reduced graphene oxide nanocomposites (rGO-Co3O4/ZnO NCs) was prepared using a two-step hydrothermal method to employed as photocatalyst for degrade parathion (PA) as a pollutant and diazinon (DZ) as a nerve agent simulant in solution. The synthesized NCs was fully characterized using X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS) and elemental mapping, thermal gravimetric analysis (TGA), Brunauer–Emmett–Teller/Barrett-Joyner-Halenda (BET/BJH), dynamic light scattering (DLS), UV–vis differential reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The structural features confirmed that the NCs was effectively synthesized, and the optical properties demonstrated that the NCs can be activated by visible light irradiation. The photocatalyst degradation rates of DZ and PA pollutants were respectively 99.6% and 99.8% in 140 min. Response surface methodology was also used to consider the effect of pertinent factors so that some parameters affecting the photocatalytic reaction, such as pH, pesticide concentration, photocatalyst amount, time, and light intensity, were optimized by an experimental design. The results show that adding ZnO nanoparticles (NPs) to the rGO-Co3O4 composition reduced the NCs band gap, which in turn reduced the rate at which photo-generated charges recombined.

Regioselective direct thiocyanation of anilines and phenols using novel hybrid nanocatalyst (MgONPs@VCA) under visible light induced photoredox catalysis

Researchers have become increasingly interested in conjugating organic moieties with metal oxide nanoparticles due to their facile, diverse applications. This study introduces a novel nanocomposite material, magnesium oxide nanoparticles conjugated vitamin C adduct (MgONPs@VCA), created by combining magnesium oxide nanoparticles (MgONPs) and vitamin C adduct (VCA) to improve its optical properties and photocatalytic activity. The identity of the fabricated nanocatalyst was confirmed using a range of techniques, including Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), Elemental Mapping, energy dispersive spectroscopy (EDS) analysis, Photoluminescence (PL), and UV–vis differential reflectance spectroscopy (DRS). Later, under visible light irradiation (blue light), the photocatalytic performance of the nanocatalyst was evaluated as a photoredox catalyst for thiocyanation of various phenols and anilines under mild conditions, resulting in good to super conversion rates. In addition, the study thoroughly investigated the stability, regeneration, reusability, catalyst dosage, and light source effects. Mechanistic studies showed that the reaction followed a photoredox radical pathway.

BaTiO 3 crystallized glass-ceramic for water cleaning application via piezocatalysis

The 20.1Na2O-23.1BaO-23TiO 2-17.4SiO 2-7.6B2O3-5.8Fe2O3-3Al2O3 glass composition was fabricated via a melt quench process. The crystalline phase of BaTiO 3 in the glass matrix was achieved through heat treatment (650 °C for 2, 4 and 8 h). The characterization of the synthesized samples were analyzed through X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and differential reflectance spectroscopy (DRS). The synthesized samples were then used as a piezocatalyst for degrading a model dye named Methylene Blue (MB) through piezocatalysis process. The glass-ceramic (heat treatment at 650 °C for 2 h) showed promising piezocatalytic activity by degrading ∼65% of the dye in 4 h under ultrasonication. Thus, the crystallization of the BaTiO3 phase in the 20.1Na2O-23.1BaO-23TiO 2-17.4SiO 2-7.6B2O3-5.8Fe2O3-3Al2O3 glass composition can be seen as a promising piezocatalyst for water pollutant removal, in addition to exhibiting antibacterial properties.

Photocatalytic degradation of metronidazole and oxytetracycline by novel l-Arginine (C, N codoped)-TiO2/g-C3N4: RSM optimization, photodegradation mechanism, biodegradability evaluation

Removal of Metronidazole (MNZ) and Oxytetracycline (OTC) from wastewater by the prepared (C, N codoped)-TiO2/g-C3N4 (Graphitic carbon nitride) was examined. l-Arginine (C, N codoped)-TiO2 and l-Arginine (C, N codoped)-TiO2/g-C3N4 photocatalysts were successfully synthesized through the sol-gel method, and optimal ratio of l-arginine:TiO2, as well as l-arginine/TiO2:g-C3N4, was determined by a kinetic study of photodegradation process. The maximum photocatalytic removal rate (0.062 min−1 for MNZ removal) was observed using 1% l-Arginine-TiO2/g-C3N4 (1:1) under visible light illumination, 2.2 and 12.4 times greater than those of 1% l-Arginine-TiO2 and pure TiO2, respectively. l-Arginine (1%)-TiO2/g-C3N4 (1:1) (co-doped-TCN) was investigated using X-ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray (EDX), Photo-luminescence (PL), and Differential Reflectance Spectroscopy (DRS) as the best-performing photocatalyst. Response surface methodology (RSM) was used to study the effect of co-doped-TCN dosage (0.5–1.0 g/L), pH of simulated wastewater (4–10), initial concentration of MNZ and OTC (50–100 mg/L), and irradiation time (30–90 min for MNZ and 20–40 min for OTC) on removal efficiency of the antibiotics. Also, their optimum values were determined by RSM. The treated pharmaceutical wastewater showed high biodegradability features with 5-day biological oxygen demand/chemical oxygen demand (BOD5/COD) of 0.51 and 0.46 after 40 and 100 min reaction for OTC and MNZ, respectively. The order of reactive species responsible for the photodegradation of pollutants was •O2─> •OH > h+>1O2. The effect of inorganic anions showed that all anions decreased the removal efficiency of both antibiotics in order of NO3─> Cl─ >SO42─>HPO42─ >HCO3─ for MNZ and NO3─> SO42─ > Cl─ >HPO42─ >HCO3─ for OTC. Also, introducing different oxidants improved the photocatalytic removal efficiency with the order of H2O2>K2S2O8> KBrO3.

Photocatalytic Degradation of Methylene Blue Dye from Wastewater by Using Doped Zinc Oxide Nanoparticles

ZnO is a semiconductor material that has important physical and chemical properties, which are frequently and significantly enhanced by the addition of impurities, such as doping. A study of the structural properties of pristine and functionalized (i.e., doped with Antimony and Tungsten) ZnO nanoparticles has been conducted for the photocatalyst-based degradation of methylene blue (MB) dye under both Ultraviolet (UV) and solar light. Authors have used a 1% concentration of dopant for doping purposes. The synthesized materials were characterized for structural analysis, functional group identification, spectroscopic measurements, and morphological examination using X-ray diffraction (XRD), Fourier transform-infrared (FTIR), UV-Vis spectroscopy (UV-Vis), and Field emission scanning electron microscope (FESEM) techniques. XRD analysis confirmed that the synthesized-doped materials retained the wurtzite hexagonal structure with a purity of 99%. Transmission electron microscope (TEM) analysis data reveals the average size of pure ZnO-NPs was found to be 7 nm; after doping the size was found to be increased to 18 nm and 9.55 nm, respectively, for ZnO-W and ZnO-Sb. As per FESEM analysis results, minor morphological changes were observed after doping. The Ultraviolet Differential reflectance spectroscopy UV-DRS study revealed the confirmation of ZnO doping with antimony and tungsten, which exhibited a blue shift. The decrease in the band-gap on doping makes the ZnO-NPs more efficient for photocatalytic applications. The photocatalytic efficiency of pristine and doped ZnO-NPs catalysts for methylene blue photocatalytic degradation (PCD) was analyzed under both UV and solar irradiation. This study analyzed the effect of pH, nano-photocatalyst dose, and initial dye concentration (ICD) on the PCD of MB. The obtained analytical results showed that the ideal conditions for the PCD of MB dye are as follows: pH = 9, the quantity of the nano-photocatalyst used was 300 mg/L, and an initial MB dye dose of 10 ppm. These conditions lead to a PCD of about 91% of the MB dye by using ZnO-Sb nano-photocatalyst on exposure to solar radiation. The reusability study also revealed the stability of nano-photocatalysts. The current research may pave the way for the removal of hazardous dyes from wastewater discharged by many industries.

Compact sample environment for in situ X-ray scattering during spin-coating.

We demonstrate a compact sample environment for the in situ study of crystallization kinetics of thin films on synchrotron beamlines, featuring atmospheric control, automated deposition, spin-coating, and annealing stages. The setup is suitable for studying thin film growth in real time using grazing-incidence X-ray diffraction techniques. Humidity and oxygen levels are being detected by sensors. The spinning stage exhibits low vertical oscillation amplitude (∼3μm at speeds up to 10 000 rpm) and can optionally be employed for antisolvent application or gas quenching to investigate the impact of these techniques, which are often used to assist thin film growth. Differential reflectance spectroscopy is implemented in the spin-coater environment for inspecting thin film thickness and optical properties. The infrared radiation-based annealing system consists of a halogen lamp and a holder with an adjustable lamp-to-sample distance, while the sample surface temperature is monitored by a pyrometer. All features of the sample environment can be controlled remotely by the control software at synchrotron beamlines. In order to test and demonstrate the performance, the crystallization pathway of the antisolvent-assisted MAPbI3 (MA = methylammonium) perovskite thin film during the spinning and annealing stages is monitored and discussed.

Hydrophobic photocatalytic composite coatings based on nano-TiO2 and fluorinated ethylene propylene prepared by electrostatic spraying

In this study, a repeatable and environmentally friendly method was utilized to prepare a hydrophobic surface with photocatalytic features can be applied on large surfaces without the complexity of the chemical methods. In this regard, titanium dioxide nanoparticles and fluorinated ethylene propylene (FEP) resins were applied on an aluminum substrate using two methods of layer-by-layer and mixing through the electrostatic spraying approach. The prepared films were analyzed by scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Reflectance Spectroscopy (DRS), energy-dispersive X-ray spectroscopy (EDS), and water contact angle (WCA) measurements. The photocatalytic activities were also explored by examining the degradation of oleic acid and four organic dyes under UV irradiation. This method led to formation of a hydrophobic photocatalytic surface with static contact angles above 130⁰. In the layer-by-layer method, the sample with one layer of titanium dioxide and three layers of FEP exhibited better hydrophobicity and photocatalytic performance. In the mixing method, better hydrophobicity and photocatalytic performance were observed in the one containing 10 wt.% TiO2.

Photocatalytic conversion of MB dye using Co3O4 QDs‐Ag2MoO4 as an active heterojunction photocatalyst under visible light irradiation

Herein, the preparation of Co3O4 QDs‐Ag2MoO4 (AMO) heterojunction was reported by a facile hydrothermal method and characterized by physicochemical methods such as Fourier transformed infrared (FT‐IR), X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDS), transmission electron microscopy (TEM), differential reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and UV–Vis. The SEM images show that AMO particles and Co3O4 QDs‐AMO have a morphology of 3D‐hexagons and nanosheets accumulated on the surface of 3D‐hexagons with an average of 36 and 28 nm in size, respectively. The Co3O4 QDs‐AMO photocatalyst was used toward the conversion of methylene blue with a removal percentage of 91%, which is 15 times more than pure AMO. The higher photoactivity of Co3O4 QDs‐AMO heterojunction should be assigned to its lower charge recombination rate compared with pure AMO nanoparticles. This heterojunction photocatalyst was removed from the mixture reaction and reused five times without a considerable decline in activity. Furthermore, a postulated mechanism by the hydroxyl radical (°OH) path was proposed.

Understanding the effect of the calcination process on the structure of mesoporous silica zirconia photocatalysts for Bisphenol A degradation

The mesoporous silica zirconia (m- SiO2/ZrO2) was successfully synthesized in this study using a microwave method, and the effect of the calcination process was studied. In this study, half of the sample was left untreated (labeled "untreated sample"), while the other half was calcined at 850 °C for 3 hours in an air atmosphere in a muffle furnace to remove the surfactant. X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible differential reflectance spectroscopy, nitrogen adsorption-desorption spectroscopy, and electron spin resonance spectroscopy were utilized in order to analyze the catalysts that were produced. The findings from the characterization showed that the calcination procedure caused the creation of oxygen vacancies and increased the surface area, both of which affected the photocatalytic activity. The photocatalytic activity of the calcined m-SiO2/ZrO2 (80%) catalyst was superior to that of the untreated m-SiO2/ZrO2 (19%) catalyst. Zirconia's greater surface area and its natural occurrence in the tetragonal phase are both to blame for this phenomenon. In addition, there is the possibility that a greater proportion of oxygen vacancy will result in a smaller band gap and a lower electron-hole recombination rate. After five cycles, the photocatalytic activity exhibited by both catalysts remained unchanged.

Green Synthesis of Copper Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Evaluation of Anti-Diabetic, Cytotoxic, Anti-Microbial, and Anti-Inflammatory Properties in an In-Vitro Approach

Green methods of synthesizing nanoparticles are safer than chemical and physical methods, as well as being eco-friendly and cost-efficient. In this study, we use copper oxide nanoparticles (CuO NPs) fabricated with Sesbania grandiflora (Sg) (Hummingbird tree) leaves to test the effectiveness of green synthesizing methods. The attained Sg-CuO NPs physical and optical nature is characterized by UV-Vis spectroscopy Differential Reflectance Spectroscopy (UV-Vis DRS), Fourier Transform Infra-Red spectroscopy (FTIR), X-ray Diffraction spectroscopy (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive X-ray Analysis (EDAX). UV-Vis spectrum for Sg-CuO NPs revealed a peak at 410 nm. SEM images showed the aggregation of needle-shaped particles, at a size of 33 nm. The amylase and glucosidase enzymes were inhibited by the Sg-CuO NPs up to 76.7% and 72.1%, respectively, indicating a possible antihyperglycemic effect. Fabricated Sg-CuO NPs disclosed the excellent inhibition of DPPH-free radicle formation (89.7%) and repressed protein degradation (81.3%). The results showed that Sg-CuO NPs display good anti-bacterial activity against the gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus). Cytotoxicity of the Sg-CuO NPs was determined using anIC50 of 37 μg/mL. Sg-CuO NPs have shown promising anti-diabetic, anti-oxidant, protein degradation-inhibiting, and anti-microbial properties. Our findings have shown that synthesized Sg-CuO NPs have biological activities that may be utilized to treat bacterial infections linked to hyperglycemia.

Green synthesis and characterization of Ni0.25Zn0.75Fe2O4magnetic nanoparticles and study of their photocatalytic activity in the degradation of aniline

Because aniline is a persistent pollutant, a cost‐effective and efficient removal method is urgently needed. This study evaluates the synergistic effect of nickel doping in spinel zinc ferrite to enhance the photocatalytic performance of magnetic nanoparticles. Herein, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), differential reflectance spectroscopy (DRS), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy‐dispersive X‐ray spectroscopy (EDX)/Map, and vibrating‐sample magnetometry (VSM) techniques were used to evaluate Ni0.25Zn0.75Fe2O4MNPs synthesis by a sol–gel method. The produced nanoparticles have a surface area of 20.325 m2 g−1. At room temperature, the nanoparticles exhibit superparamagnetic characteristics and can be readily separated from the aqueous solution. The bandgap has been determined to be 1.83 eV using Tauc's plot. In addition, the photocatalytic activity of as‐prepared Ni0.25Zn0.75Fe2O4MNPs for aniline degradation under visible light irradiation was examined. The photocatalytic results demonstrate that nickel‐doped zinc ferrite has high photocatalytic activity in aniline degradation. Additionally, Ni0.25Zn0.75Fe2O4magnetic nanoparticles (MNPs) are highly magnetic in nature, which simplifies separation and repetitive reuse.

Ultrasound-assisted photocatalytic decomposition of rifadin with biochar and CNT-based NiCr layered double hydroxides

Modification of layered double hydroxides (LDHs) is known to be beneficial for boosting the consistent formation of reactive oxygen species (ROSs) and enhancing the photocatalytic process. Herein, a facile synthesis method for preparing carbon nanotube (CNT) and biochar (BC)-based NiCr LDH (NC) nanocomposites as a sonophotocatalyst for the efficient degradation of rifadin (RA) was provided. The formation of thin nanosheet structures of NC along with porous and nanotube structures of BC and CNT was well approved by scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). The bandgaps of the nanocomposites and pristine LDH are determined by differential reflectance spectroscopy (DRS) analysis. Results unveiled that sonophotocatalysis presented high efficacy in comparison with sonocatalysis and photocatalysis. Under optimized conditions, a 15 mg L−1 of RA at pH 8 treated with 1 g L−1 of NiCr LDH/BC (NC/BC) demonstrated 80.3% sonophotocatalytic degradation during 90 min. To shed light on the durability and stability of NC/BC, four consecutive cycles were operated. The chemical structure and surface morphology of the reused catalyst were stable, revealed by SEM and Fourier transform infrared (FTIR) analyses. It is deduced that NC/BC is an advantageous sonophotocatalyst for the decomposition of emerging pharmaceuticals.