Recently, green synthesis approaches for metal oxide nanoparticles have gained significant attention as viable alternatives to conventional methods owing to their simplicity, cost-effectiveness, and environmental sustainability. The present study aims to synthesize cerium oxide nanoparticles (CeO2 NPs) via a hydrothermal-assisted green route using Cannabis indica leaves extract, with varying extract-to-precursor volume ratios. As-synthesized CeO2 NPs are characterized using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray analysis, dynamic light scattering, and diffuse reflectance spectroscopy. It is observed that both the crystallite size and optical band gap of the synthesized CeO2 NPs depend on the volume of Cannabis indica extract. XRD and Raman spectroscopic analyses confirmed the formation of polycrystalline CeO2 NPs featuring a cubic fluorite crystal structure. Morphological analysis indicated the formation of composed NPs of diverse sizes in spherical and semi-spherical geometry. The optical band gap is predicted from diffuse reflectance by the Kubelka–Munk function and Tauc’s plot. The photocatalytic performance of the chosen CeO2 NPs is assessed by monitoring the solar-light-induced degradation of methylene blue and methyl orange dyes. The degradation process under optimal conditions predominantly obeys pseudo-first-order kinetics. Furthermore, a 1 mg/mL dosage of CeO2 NPs exhibits higher degradation efficiency for 5 ppm dye solutions under visible light irradiation.

Cerium oxide nanoparticles (CeO2 NPs) were synthesized via chemical and green routes assisted by the hydrothermal technique using NaOH and Achyranthes aspera (A. aspera) leaf extract as reducing cum stabilizing agents. Structural, morphological, and optical properties of the nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and UV-visible spectroscopy. The crystallite size estimated by the Debye-Scherrer formula was found to be 12.83 nm and 5.75 nm for chemical and green synthesized CeO2 NPs, respectively. The photocatalytic activity of CeO2 NPs was examined through the photocatalytic degradation of MB dye under natural sunlight. After 60 min of sunlight exposure, the degradation efficiency of MB was limited to 11.53% for chemically synthesized CeO2 nanoparticles; however, green-synthesized CeO2 nanoparticles exhibited a pronounced enhancement, achieving 78.41% degradation. Overall, this study demonstrates the advantages of plant-mediated synthesis over the conventional chemical method and suggests that CeO2 NPs hold significant promise for sustainable applications, particularly in water treatment.

Current environmental challenges require highly efficient materials for environmental remediation. Polymer-assisted CuS structures have shown strong potential for reducing environmental pollution. In this study, sheet-like and spherical CuS structures were synthesised through an autoclaved solvothermal method for 16 h using varying concentrations of PVP additive. XRD analysis confirmed the formation of a polycrystalline hexagonal phase. FE-SEM observations revealed mixed morphologies consisting of hexagonal sheets and spherical particles with flaky nanostructures. EDS results indicated a slightly copper-rich composition with a Cu:S atomic ratio of ∼60:40. XPS analysis confirmed the presence of both Cu(I) and Cu(II) oxidation states. The synthesised CuS structures exhibited broad optical absorption in the 330–750 nm range with an absorption edge near 330 nm. The photocatalytic activity of PVP-assisted CuS catalysts was investigated for the degradation of methylene blue and crystal violet dyes under natural sunlight.

Application of drug conjugated iron oxide hematite ( α -Fe _2 O _3 ) nanoparticles are of tremendous interest in biomedicine nowadays. Meanwhile, green production of iron oxide nanoparticles is gaining favour due to its sustainability, ease of usage, and biocompatibility. Therefore, this work reports on the use of hexahydrate ferric chloride and nerium oleander flower extract to synthesize nanoscaled hematite ( α -Fe _2 O _3 ) iron oxide particles conjugated with various drugs for antibacterial agents. Diverse morphological, physicochemical, structural, optical, and magnetic characteristics have been characterized using FESEM, EDX, XRD, UV–vis, FTIR, Raman and vibrating sample magnetometer. The synthesis of the polyshaped iron oxide nanoparticles, with average sizes ranging from 47.2 ± 20 nm, was accomplished. Furthermore, temperature-dependent variations in magnetic behavior were observed during calcination. The XRD and Raman spectra revealed hematite ( α -Fe _2 O _3 ) type formation of iron oxide nanoparticles. Only calcinated IO-NPs at high temperatures (700 °C) demonstrated low coercivity and residual magnetism, which revealed weak ferromagnetic ordering; other calcinated samples, including nascent ones, showed incredibly weak ferromagnetic ordering. Besides, the effectiveness of drug-encapsulated iron oxide nanoparticles against bacteria in vitro was examined. It was interesting to observe that gentamycin-coated IO-NPs tended to be more susceptible to S. aureus than E. coli bacteria, but streptomycin-conjugated IO-NPs showed the reverse trend. However, as compared to the nascent sample and the high temperature (700 °C) calcinated sample, both antibiotic-loaded IO-NPs displayed better inhibitory abilities.

Diabetes is a chronic disease that affects millions of humans worldwide. This review article provides an analysis of the recent advancements in non-invasive blood glucose monitoring, detailing methods and techniques, with a special focus on Electromagnetic wave microwave glucose sensors. While optical, thermal, and electromagnetic techniques have been discussed, the primary emphasis is focussed on microwave frequency sensors due to their distinct advantages. Microwave sensors exhibit rapid response times, require minimal user intervention, and hold potential for continuous monitoring, renders them extremely potential for real-world applications. Additionally, their reduced susceptibility to physiological interferences further enhances their appeal. This review critically assesses the performance of microwave glucose sensors by considering factors such as accuracy, sensitivity, specificity, and user comfort. Moreover, it sheds light on the challenges and upcoming directions in the growth of microwave sensors, including the need for reduction and integration with wearable platforms. By concentrating on microwave sensors within the broader context of non-invasive glucose monitoring, this article aims to offer significant enlightenment that may drive further innovation in diabetes care.

In the present report, titanium oxide (TiO2) nanocrystals (NCs) were synthesized using the green route utilizing Ocimum basilicum leaf extract (OBLE). X-ray diffraction (XRD) studies revealed that TiO2 NCs exhibit tetragonal crystal configuration with anatase-type symmetry with \(I{4}_{1/}amd\) space group. The phenolic groups (–OH) present in OBLE were detected as the bend appeared at 3420 cm− 1 in the infrared spectrum. The characteristic hump positioned at 331 nm in the UV–visible diffuse reflectance spectrum (UV–DRS) of biosynthesized TiO2 NCs confirmed the formation of nanoparticles and the optical band gap of TiO2 NCs was found to be 3.41 eV as evaluated from Tauc’s plot. The surface morphology of TiO2 NCs showed minute agglomeration with an average particle size of 11.8 ± 0.66 nm as obtained from statistical analysis of the particle size distribution. The cytotoxic activity of TiO2 NCs was investigated against MDA–MB 231 cancer cells and dose-dependent cell inhibition was observed with a low IC50 value of 13.35 µg/mL after 48 h of incubation time.

In the present research paper, Mn (transition metal) and Ce (rare earth metal) doped and co-doped ZnO nanoparticles were synthesized using a cost-effective sol-gel technique. As synthesized samples were characterized using x-ray diffraction and field emission scanning electron microscope to examine the structure and morphology respectively. The optical properties were examined by UV-Visible and photoluminescence spectroscopic techniques. The synthesized samples were used as photoanode for the fabrication of dye-sensitized solar cell (DSSC). The utilization of a photoanode, containing Mn and Ce doped and co-doped in ZnO, in DSSC leads to a significant enhancement in photovoltaic conversion efficiency with natural dye lawsonia inermis. Different combinations of Mn or Ce doped and co-doped ZnO nanoparticles were used for testing their effectiveness as photoanode in DSSC. It was observed that the efficiency for Mn and Ce co-doped ZnO photoanode-based DSSC was found to be 0.2118%, which is approximately a 750% increase as compared to bare ZnO photoanode based DSSC. The enhancement in the efficiency of DSSCs was due to the formation of a blocking layer by Mn ions which helps to stop the flow of electrons backward and the broadening of the spectrum region with the help of Ce ions using up/down conversion process also helps to achieve higher efficiency. This enhancement in the efficiency of DSSC may be attributed to the synergic effect of Mn and Ce.

In the dynamic field of materials science, the bismuth, strontium, and lanthanum-based double perovskites have shown great potential in research areas because of their unique structural features. This review explores the fabrication, structure, and distinct electrical, dielectric, and magnetic traits of bismuth-based double perovskites, highlighting their potential in modern electronics and energy conversion. Achieving better efficiencies in perovskite-based solar cells, these materials surpass many third-generation solar technologies. Bismuth-based double perovskites, with their multiferroic behaviour and topological insulator properties, show promise for applications in catalysis, spintronics, and solid-state electronics. Lanthanum-based double perovskites enhance energy storage performance through chemical stability and high pseudo capacitance. Additionally, these materials exhibit magnetoresistance and magnetocapacitance at ambient temperature, enabling their usage in various applications. This review provides a comprehensive examination of La, Sr, and Bi-based double perovskites, emphasizing their significance and potential for future advancements in materials science.

The present work elucidates a study on the synthesis and characterization of nanostructured NiS thin films, an optical absorber material. NiS films have been deposited on glass substrates using a simple and cost-effective chemical solution route. The deposition process has been accomplished using an aqueous solution of nickel chloride, thiourea, ammonia and Triton. As-deposited and thermally annealed films have been characterized using X-ray diffractometry, Fourier transform infrared spectrometry, scanning electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, and UV-visible spectrometry. It has been observed that the deposited films are nanocrystalline in nature and belong to the rhombohedral structure of the millerite phase. The diffraction peaks become more sharp, discrete and intense whereas the crystallite size increases from 9.89 to 11.78 nm with annealing treatment. Some variations in the infrared peaks have been observed with annealing. The characteristic peak for Ni-S vibration has been observed at similar to 604 cm-1. The surface of the films is smooth, uniform, and free from cracks and pinholes. The optical absorbance analysis has confirmed that NiS films possess a direct optical band gap whose values vary from 1.50 to 1.45 eV with annealing.

Although the correlation between a glucose concentration and its permittivity is somewhat weak to be measured, the glucose concentration is a strong function of the dispersion. In terahertz or microwave frequencies, dispersion can be observed or measured along the interface between an object under test and a metamaterial or surface plasmonic surface, which is basically a metal structure characterized by periodically arrayed holes, grooves, or metal grating. In this work, we have focused on the method for improving the accuracy of a glucose measurement by proposing a new triple-band microwave sensor design and by measuring the resonant frequency shift associated with a glucose concentration at three frequencies simultaneously. A new triple-band glucose sensor of dimension (30mm x 10mm) was designed with the main sensing region as compact as 14mm with two conducting microstrip lines on both ends of the sensor. The sensor design has been realized on a thin flexible substrate of 0.15mm thickness. The proposed sensor has been designed to measure glucose concentration through the measurement of a resonant frequency shift at 650MHz, 4.45GHz, and 10.35GHz. Overall, the glucose concentration has been found to be correlated positively and linearly with the resonant frequency shift at these frequencies.

Photocatalysts have gained much attention because of the water pollution instigated by the rapid usage of organic dyes for industrial needs. The degradation of these dyes using photocatalysts under natural light is an economical and popular method for water treatment. There is a need to synthesize photocatalytic materials which can generate reactive oxygen species under natural light. Hence, keeping in mind the above point, rose flower-shaped CuS nanostructures have been synthesized first time by solvothermal technique by varying reaction duration. The self-assembled powder of CuS nanostructures is characterized using XRD, FE-SEM, TEM, DLS, EDS, XPS, Raman, FT-IR, and UV–visible spectroscopy. The XRD and TEM analyses confirmed the formation of a polycrystalline hexagonal structure with prominent diffraction peaks. FE-SEM study shows the formation of uniformly self-assembled rose flower-shaped nanostructures of size 2–3 μm composed of densely packed nanoparticles. XPS study shows the presence of Cu(II) and Cu(I) states of copper in the synthesized batch and stoichiometric composition Cu:S is found to be 60:40 at.

Due to their dynamic features, nanoparticles of semiconductor materials have been created rapidly in the past few decades and are being investigated for potential uses in a variety of disciplines. The present study focuses on the substitution of Ga 3+ ions in ZnS nanoparticles to modify their structural, morphological, compositional, optical, and dielectric properties. The Ga-doped (ZnS:Ga) nanoparticles for various Ga 3+ ions concentrations ( i.e. , 0%, 2%, 4%, 6%, 8%, 10% & 12%) are synthesized using direct co-precipitation technique and utilizing precursor solutions of Zn(CH 3 COO) 2 , Na 2 S and Ga 2 (SO 4 ) 3 along with EDTA as a stabilizing agent. The structural analysis reveals that the synthesized nanoparticles exhibit a cubic crystal structure with high crystallinity and preferred ( 111 ) orientation. Fluctuations in different structural parameters have been noticed without any alteration in crystal structure after the substitution of Ga ions in ZnS matrix. The surface morphology exposes spherical-shaped ZnS:Ga nanoparticles whose compactness varies with doping concentrations. FT-IR and EDS spectra of the nanoparticles identify the presence of different functional groups and elements in the expected compositions. A blueshift in the absorption edge has been observed for all the concentrations of ZnS:Ga w.r.t. pristine ZnS indicating quantum confinement in the synthesized nanoparticles which further results in the broadening of optical bandgap in comparison to bulk value for ZnS. The room temperature dielectric measurements for ZnS:Ga nanoparticles show a high dielectric constant value up to doping level 8% beyond which it decreased. The ac conductivity values in this study varied from 10 −4 Ω −1 m −1 for pristine to 9.66 × 10 −3 Ω −1 m −1 for ZnS:Ga 12%.

The challenge of dealing with synthetic dye pollution in waste from the leather industry requires continual research and development. Although numerous dyes used in the textile, food, and other industries have been found to be degraded by photocatalyst based on zinc oxide nanoparticles (ZnO NPs), no thorough studies on the degradation of leather dye from dye-containing wastewaters from tanneries have been reported to date. Hence, this study investigates the efficient photocatalytic destruction of leather dye using ZnO NPs produced by chemical precipitation method. The influence of calcination temperatures ranging from 400 to 600 °C on the structural and optical characteristics of ZnO NPs was investigated. XRD examination revealed an increase in crystallite size as the calcination temperature increased, presumably due to the merger of smaller crystallites into larger ones. Meanwhile, the polycrystalline and wurtzite structure of the synthesized ZnO NPs was observed, with particle diameters ranging from 40 to 90 nm and an average size of around 62 nm. UV–vis spectra revealed a decrease in energy band gap (3.15 to 3.05 eV), which was ascribed to an increase in crystallite size produced by higher calcination temperature from 400 to 600 °C. The photocatalytic degradation of leather dye was studied further. It has been demonstrated that ZnO NPs synthesized at a calcination temperature of 400 °C can remove 90% of the leather dye in 30 min. The dynamics of deterioration were also studied. It was discovered that the degradation of leather dyes best fitted the pseudo-first-order kinetics, with superoxide ions being the most likely species.

Surface functionalization of iron oxide nanoparticles (Fe2O3 NPs) with antibiotics is a novel approach that opens the door to drug delivery applications. In the present work, we report iron oxide nanoparticles synthesized by chemical co-precipitation method. As-synthesized nanoparticles were characterized using field emission scanning electron microscopy (FESEM) , energy dispersive X-ray (EDX), X-ray diffraction (XRD), ultraviolet (UV)–visible (Vis) spectroscopy, Fourier transform infrared (FTIR), and vibrating sample magnetometer (VSM). The poly-shaped Fe2O3 NPs of size (34 ± 10) nm with hematite (α-Fe2O3) phase were synthesized. The antibacterial activity of chloramphenicol and gentamicin and their formulation with encapsulated iron oxide nanoparticles was investigated by the agar well diffusion technique. Drug-encapsulated Fe2O3 NPs showed antibacterial activity against Escherichia coli and Staphylococcus aureus strains, possibly in a dose-dependent manner. Significant effectiveness was confirmed by the increase in the single range of inhibition against the tested microorganisms. Furthermore, the effect of iron oxide nanoparticle concentrations ranging from 1 to 9 μg/μL on bacterial growth was examined.

Trivalent metal cations modified polycrystalline ZnS nanoparticles, Zn0.95X0.05S (X = Al3+, Ga3+, & In3+) NPs, were synthesized using co-precipitation technique and their physicochemical investigations were carried out. Structural analysis revealed that all the compositions display cubic crystallinity having Fm3m space group as evident from Rietveld refinement technique. The average crystallite size evaluated using Williamson-Hall plot was found to be 4.75 nm, 5.17 nm, and 5.76 nm for Zn0.95Al0.05S NPs, Zn0.95Ga0.05S NPs, and Zn0.95In0.05S NPs respectively. Microstructural studies depicted the nanoscale formation of nanoparticles with uniform grain distribution where the average grain size was observed between 38.2 nm and 45.4 nm. FT-IR spectra analysis confirmed the formation of Zn0.95Al0.05S, Zn0.95Ga0.05S, and Zn0.95In0.05S NPs with high frequency stretching vibrations about 465 cm- 1 and 654 cm-1, belonging to the weak and strong edge of elemental regions. The value of the dielectric constant in the lower frequency region was found to be maximum (27.2) for Zn0.95In0.05S NPs and least (17.8) for Zn0.95Al0.05S NPs. It was observed that ac conductivity increases sharply with the increasing frequency of the applied electric field. The measured values of ac conductivity at 1 kHz for Zn0.95Al0.05S NPs, Zn0.95Ga0.05S NPs, and Zn0.95In0.05S NPs were found to be 5.06 x 10-7 omega- 1cm- 1, 1.24 x 10-6 omega- 1cm- 1, and 1.28 x 10-6 omega- 1cm- 1, respectively.

Herein we demonstrate a Facile, non-toxic and green approach for the fabrication of Pristine and Sm3+ (1-7 mol %) doped MgO by Jamun fruit extract, the phytochemicals present in the fruit extract made possible bio-reduction of Mg(NO3)2. Photocatalytic results exhibit the exceptional catalytic activity on degradation of Fast orange red dye. This work presents a highly-efficient nanomaterial to design the system for the environmental pollution purification. Furthermore, Sm3+ doped MgO nanomaterials showed noble electrochemical behavior as an electrode material for super capacitors and battery, sensor applications. Further, antibacterial activity demonstrates an effective bactericidal activity against pathogens.

In the present report TiO2 nanoparticles co-doped with iron and different mol % of silver have been successfully synthesized by sol-gel route and studied by X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), UV-visible absorption spectroscopy (UV-Vis), Photoluminescence spectroscopy (PL), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), and FTIR spectroscopy. The XRD data analysis confirms the formation of mixed phases of TiO2 (anatase) and Ag2O phase. The crystalline size was vary from 48.0 nm to 44.6 nm determined from XRD further verified from TEM micrograph. The EDXS measurements suggest that iron is completely incorporated however silver has not incorporated into TiO2 matrix. The optical band gap of the prepared nanoparticles was calculated by UV-Visible absorption spectroscopy using Tauc-Davis and Mott expression and found to varying from 2.92 to 2.30 eV. The absorption bands in the UV-visible spectra shift towards higher wave length region and appearance of emission bands in PL spectra confirms the formation of energy substates in the forbidden gap of the prepared samples. TEM micrographs showed that prepared nanoparticles are somewhat spherical in shape. The formation of different functional groups and bonds in the structure of synthesized nanoparticles as observed in FTIR spectra helps in degradation of organic dyes (congo red and methyl orange) and enhance the photocatalytic activity under visible light. It is observed that the higher doping concentration of silver causes to decrease the band gap energy as a result the carrier recombination rate decreases and therefore enhance the degradation efficiency.

Deteriorating of quality of water is a desperate threat world-wide. Industrial development added regularly a huge amount of organic and inorganic contaminants in water. Therefore, eradication of these contaminants is highly essential for the well-being of biotic components. Adsorption assisted technologies are one of the most benign and principally used ones owing to their higher efficiencies at lower costs, and independence on complex technological supports. In recent years, carbon nanomaterials, such as activated carbons, carbon nanotubes, graphene based materials, and carbon dots have been broadly adapted as adsorbents because of their outstanding surface characteristics. Graphene oxide and other oxidized forms of carbon are rich in functional groups and provide strong acidity to the surface, thus they are excellent adsorbents for basic and cationic compounds.Here, we reviewed the various types of pollutants found in aquatic biota with some basics on fundamentals and mechanistic features of adsorption, adsorption efficiency regulating factors. The article emphasized on the performances of carbon nanomaterials and associated nanocomposites for the adsorption of various pollutants. Review also addressed the essential issues which is to be considered for the technical development and commercial application of the carbon-assisted materials as nanoadsorbents for water decontamination.

Undoped TiO2 and Mo/N co-doped TiO2 nanoparticles have been fabricated by sol gel technique. The average particle size of nanoparticles was calculated from the line broadening of (101) peak of XRD pattern and further verified by High Resolution Transmission Electron Microscopy (HRTEM) are in good agreement. The decrease in particle size 28.5 to 15.0 nm was observed with increase of molybdenum concentration. The surface morphology of all samples was studial by Field Emission Scanning Electron Microscopy shows small agglomeration. The optical band gap energy was calculated using UV-visible absorption spectroscopy and found to decrease in increase of doping concentration. The presence of defect levels caused by oxygen vacancies has been confirmed by Photoluminescence spectra. The emission bands observed at 453.9, 470.6, 485.7, 495.8 and 535 mu could be arising from surface states. The phase composition and elemental analysis of synthesized samples was estimated from Energy dispersive X-ray spectroscopy. The effect of doping concentration on structural formation was studied by FTIR spectroscopy. The Photocatalytic activity of synthesized samples for degradation of Congo red (CR) and Methyl orange (MO) dyes as standard pollutants was investigated under visible light source. The increase in doping concentration causes enhance in photocatalytic activity of the synthesized nanoparticles which is attributed from the decrease in electron-hole pair recombination rates. The degradation efficiency against congo red dye is very high compared to methyl orange dye. These observations suggest that co-doped synthesized nanoparticles are suitable for complete degradation of congo red dye and are not able to degrade methyl orange dye.

Graphene is an excellent nanoscale allotrope of carbon in which carbon atoms are bonded through sp2 hybridization. Graphene itself or its thin film exhibits excellent transparency to visible light. Silver nanowires are also being used for making transparent electrodes. Herein, we prepared a thin film of reduced graphene oxide and silver nanowires on flexible PET (polyethylene terephthalate) substrate. Characterization of graphene oxide/reduced graphene oxide has been carried out through X-ray diffractometry, FTIR (Fourier transformed infrared spectroscopy). Ultraviolet-visible spectroscopy and I-V measurements demonstrated high conductivity and transmittance of the above prepared film.