Multifunctional integration of tungsten oxide (WO3) coating: A versatile approach for enhanced performance of antibiotics against single mixed bacterial infections.

Nanomaterials containing tungsten (TNMs), characterized by diverse nanostructures had been extensively used in biomedical sector. Despite numerous reports focusing on TNM applications in specific biomedical areas, there is a noticeable absence of comprehensive studies that focused on detailed characterization of nanomaterials along with their biological applications. The present work described the structural, morphological, and antimicrobial properties of tungsten oxide (WO3) nanoparticles coated by antibiotics (nanobiotics), and their application on single and mixed bacterial culture. The nanobiotics included in this study were WO3 coated with ampicillin (W+A), WO3 coated with penicillin (P+W), and WO3 coated with ciprofloxacin (C+W). Techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), Fourier transforms infrared spectroscopy (FTIR), Rrman spectroscopy, and UV-visible spectroscopy were used to characterize synthesized nanoparticles. The minimum inhibitory concentration of C+W nanobiotic against S. aureus, E. coli, and mixed culture (S. aureus +E. coli) was lower than that of P+W and A+W. The impact of incubation period showed significant differences for each of nanobiotic against S. aureus, E. coli, and mixed culture. However, there were also non-significant differences among incubation periods for antibacterial activity of nanobiotics. It was pertinent to note that percentage variation in susceptibility of S. aureus with respect to mixed culture remained higher as compared to E. coli, indicating it stronger candidate imposing resistance. This paper thus suggested the strategy of coating of antibiotics with with WO3 nanoparticles as an ideal combination for resistance modulation against single and mixed culture bacteria.

Resistance Modulation of Individual and Polymicrobial Culture of S. aureus and E. coli through Nanoparticle-Coupled Antibiotics.

Polymicrobial mastitis is now becoming very common in dairy animals, resulting in exaggerated resistance to multiple antibiotics. The current study was executed to find drug responses in individual and mixed Culture of Staphylococcus aureus and Escherichia coli isolated from milk samples, as well as to evaluate the antibacterial potential of tungsten oxide nanoparticles. These isolates (alone and in mixed culture) were further processed for their responses to antibiotics using the disc diffusion method. On the other hand, tungsten oxide WO3 (W) nanoparticles coupled with antibiotics (ampicillin, A, and oxytetracycline, O) were prepared through the chemical method and characterized by X-ray diffraction, scanning electron microscopy (SEM), and UV-visible techniques. The preparations consisting of nanoparticles alone (W) and coupled with ampicillin (WA) and oxytetracycline (WO) were tested against individual and mixed Culture through the well diffusion and broth microdilution methods. The findings of the current study showed the highest resistance in E. coli was against penicillin (60%) and ampicillin (50%), while amikacin, erythromycin, ciprofloxacin, and oxytetracycline were the most effective antibiotics. S. aureus showed the highest resistance against penicillin (50%), oxytetracycline (40%), and ciprofloxacin (40%), while, except for ampicillin, the sensitive strains of S. aureus were in the range of 40-60% against the rest of antibiotics. The highest zones of inhibition (ZOI) against mixed Culture were shown by imipenem and ampicillin, whereas the highest percentage decrease in ZOI was noted in cases of ciprofloxacin (-240%) and gentamicin (-119.4%) in comparison to individual Culture of S. aureus and E. coli. It was noteworthy that the increase in ZOI was not more than 38% against mixed Culture as compared to the individual Culture. On the other hand, there was a significant reduction in the minimum inhibitory concentration (MIC) of nanoparticle-coupled antibiotics compared to nanoparticles alone for individual and mixed-culture bacteria, while MICs in the case of mixed Culture remained consistently high throughout the trial. This study therefore concluded that diverse drug resistance was present in both individual and mixed-culture bacteria, whereas the application of tungsten oxide nanoparticle-coupled antibiotics proved to be an effective candidate in reversing the drug resistance in bacterial strains.

Recent advances in synthesis and characterization of iron-nickel bimetallic nanoparticles and their applications as photo-catalyst and fuel additive.

Iron-nickel bimetallic nanoparticles (Fe-Ni BMNPs) are prepared by combining two different metals by using the bottom-up approach. The resulting material has entirely different properties as compared to both the metals. The product is examined by using different analytical instruments such as.; scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), MDIJADE, ORIGIN pro to characterize their morphology, crystallinity and elemental composition and the final data has been statistically analyzed. SEM findings show that most nanoparticles are irregular in form and range in size from 10 nm to 100 nm. The findings of the TEM verified that the particles between 10 nm and 50 nm are irregular in size shape. The products acquired utilized as a fuel additive to monitor oil effectiveness by studying various parameters. The degradation of methylene blue dye depends directly on the concentration of the nanocatalyst. Different parameters also use the freshly prepared bimetallic nanocatalyst to investigate the efficacy of the kerosene fuel. By adding a tiny quantity of the nanocatalyst, the value of the flash point and fire point is significantly reduced. The nanocatalyst does not affect the cloud point and pour point to a large extent. The bimetallic nanocatalyst therefore has very excellent catalytic characteristics.

Sodium Alginate-Based MgO Nanoparticles Coupled Antibiotics as Safe and Effective Antimicrobial Candidates against Staphylococcus aureus of Houbara Bustard Birds.

Alternative and modified therapeutic approaches are key elements in culminating antibiotic resistance. To this end, an experimental trial was conducted to determine the cytotoxicity and antibacterial potential of composites of magnesium oxide (MgO) nanoparticles and antibiotics stabilized in sodium alginate gel against multi-drug-resistant Staphylococcus aureus isolated from a houbara bustard. The characterization of preparations was carried out using X-ray diffraction (XRD), scanning transmissible electron microscopy (STEM), and Fourier-transform infrared spectroscopy (FTIR). The preparations used in this trial consisted of gel-stabilized MgO nanoparticles (MG), gel-stabilized tylosin (GT), gel-stabilized ampicillin (GA), gel-stabilized cefoxitin (GC), gel-stabilized MgO and tylosin (GMT), gel-stabilized MgO and cefoxitin (GMC), and gel-stabilized MgO and ampicillin (GMA). The study presents composites that cause a lesser extent of damage to DNA while significantly enhancing mitotic indices/phases compared to the other single component preparations with respect to the positive control (methyl methanesulphonate). It was also noted that there was a non-significant difference (p > 0.05) between the concentrations of composites and the negative control in the toxicity trial. Studying in parallel trials showed an increased prevalence, potential risk factors, and antibiotic resistance in S. aureus. The composites in a well diffusion trial showed the highest percentage increase in the zone of inhibition in the case of GT (58.42%), followed by GMT (46.15%), GC (40.65%), GMC (40%), GMA (28.72%), and GA (21.75%) compared to the antibiotics alone. A broth microdilution assay showed the lowest minimum inhibitory concentration (MIC) in the case of GMA (9.766 ± 00 µg/mL), followed by that of GT (13.02 ± 5.64 µg/mL), GMC (19.53 ± 0.00 µg/mL), GA (26.04 ± 11.28 µg/mL), GMT (26.04 ± 11.28 µg/mL), MG (39.06 ± 0.00 µg/mL), and GC (39.06 ± 0.00 µg/mL). The study thus concludes the effective tackling of multiple-drug-resistant S. aureus with sodium-alginate-stabilized MgO nanoparticles and antibiotics, whereas toxicity proved to be negligible for these composites.

Application of Cypermethrin-Coated ZnS and ZnO Nanoparticles against Rhipicephalus Ticks.

Rhipicephalus ticks are described as important ticks impacting the costs of livestock rearing and by-products sale. The prevalence and response of ticks towards cypermethrin sprays indicate the need to implement the rational use of acaricides. In our previous studies, ZnO nanoparticles were shown to inhibit the major life-cycle stages of Hyalomma ticks, indicative of promising application of nanomaterials against the hard ticks. The current study was designed to probe into one of alternative options to curtail Rhipicephalus ticks by employing cypermethrin-coated nanoparticles of ZnO (C-ZnO NPs) and ZnS (C-ZnS NPs). The nanocomposites showed a roughly spherical type of morphology and various size dimensions upon characterization using SEM and EDX. Female ovipositioning was declined up to only 48% in ZnS and up to 32% in ZnO NPs even after 28 days in vitro. Similarly, the larval hatching was also impacted, leading to a hatching percentage of 21% and 15% by application of C-ZnS NPs and C-ZnO NPs, respectively. The LC90 in female adult groups were 3.94 mg/L and 4.27 mg/L for the C-ZnO NPs and C-ZnS NPs groups, respectively. Similarly, the larval groups had LC90 of 8.63 and 8.95 mg/L for the C-ZnO NPs and C-ZnS NPs groups. The study is a proof of the concept for incorporating effective and safe nanocomposites as acaricides. The studies on the efficacy and spectrum of non-target effects of nanomaterial-based acaricides can further refine the research on finding novel alternatives for tick control.

Modification of the drug resistance of emerging milk-borne pathogens through sodium alginate-based antibiotics and nanoparticles.

Streptococcus agalactiae and Klebsiella pneumoniae are emerging as major milk-borne pathogens. Additionally, resistance to antibiotics of pathogens is of concern. Therefore, this study investigated the prevalence and drug resistance of S. agalactiae and K. pneumoniae in mastitis milk samples and assessed the antimicrobial potential of sodium alginate (G)-stabilized MgO nanoparticles (M) and antibiotics (tylosin [T] and ampicillin [A]) against both of these pathogens. A total of n = 200 milk samples from cattle were collected using purposive sampling, and standard microbiological approaches were adopted to isolate target bacteria. Parametric and non-parametric statistical tests were used to analyze the obtained data. Four preparations, GT (gel-stabilized tylosin), GA (gel-stabilized ampicillin), GTM (tylosin and MgO nanoparticles stabilized in gel), and GAM (ampicillin and MgO nanoparticles stabilized in gel), were evaluated against both bacteria through well diffusion and broth microdilution method. The analysis revealed that 45.24% (95/210) of the milk samples were positive for mastitis, of which 11.58% (11/95) were positive for S. agalactiae and 9.47% (9/95) were positive for K. pneumoniae. S. agalactiae had a significantly higher zone of inhibition (ZOI) than K. pneumoniae against penicillin, tetracycline, and amoxicillin, whereas the opposite was observed against imipenem and erythromycin. All gel (G)-based preparations showed an increase in the percentage of ZOI compared with antibiotics alone, with GTM presenting the highest of all, i.e., 59.09 and 56.25% ZOI compared with tylosin alone against S. agalactiae and K. pneumoniae, respectively. Similarly, in a broth microdilution assay, the lowest MIC was found for K. pneumoniae (9.766 ± 0.0 µg/mL) against GTM, followed by GT, GAM, and GA after incubation for 24 h. A similar response was noted for preparations against S. agalactiae but with a comparatively higher MIC. A significant reduction in MIC with respect to incubation time was found at 8 h and remained until at 20 h against both pathogens. The cytotoxicity of the MgO nanoparticles used in this study was significantly lower than that of the positive control. Overall, this study found that K. pneumoniae and S. agalactiae appeared higher in prevalence and antimicrobial resistance, and sodium alginate-based antibiotics and MgO nanoparticles were effective alternative approaches for tackling antimicrobial resistance.

Comparative investigation of the catalytic application of α/ß/γ-MnO2 nanoparticles synthesized by green and chemical approaches.

Three phases (α, ß, and γ) of manganese dioxide (MnO2) are successfully stabilized in a single entity for the first time. For this purpose, Citrullus colocynthis (bitter apple) extract is used as a natural surfactant in green synthesis. MnO2 nanoparticles were synthesized in the presence and absence of plant extracts under the same conditions. The morphology of both products is analysed by SEM and STEM to understand the role of plant extract in controlling the morphology of particles. The crystallinity and composition are analysed by XRD and confirmed that the product is composed of multiple phases α, ß, and γ. The reduction of dyes and nitroarenes is studied using MnO2 nanoparticles (green and chemical products) as catalysts. The apparent rate constant, a percentage reduction, time reduction and reduced concentration compare the activities of both catalysts. After comparative data analysis, the catalytic reduction of picric acid is found fastest among all the substrates. All the results are analysed based on structure, functional group and affinity towards catalysts.

Evaluation of Sodium Alginate Stabilized Nanoparticles and Antibiotics against Drug Resistant Escherichia coli Isolated from Gut of Houbara Bustard Bird.

Alternative approaches and/or modified approaches to tackle resistance in gut microbes are need of the hour. The current study was planned to find the resistance modulation and toxicity potential of sodium alginate stabilized MgO nanoparticles and antibiotics against Escherichia coli (E. coli) isolated from the gut of Houbara bustard bird (n = 105 fecal samples). The preparations consisted of gel stabilized ampicillin (G+A), gel stabilized MgO and ampicillin (G+M+A), gel stabilized MgO and cefoxitin (G+M+C), gel stabilized tylosin (G+T), gel stabilized MgO and tylosin (G+M+T), and gel stabilized MgO (M+G). The fecal samples showed 53% (56/105) prevalence of E. coli which was found to be significantly (p < 0.05) associated with most of the assumed factors and resistant to multiple drugs. G+M+T showed the lowest (4.883 ± 0.00µg/mL) minimum inhibitory concentration (MIC) followed G+M+C, G+M+A, G+A, M+G, and G+T. Significant reduction (p < 0.05) in MIC with respect to incubation interval found at the 16th hr for G+M+A, G+A, and G+M+C that further remained nonsignificant (p > 0.05) onwards until the 24th hr of incubation. In the case of G+T and M+G, significant reduction in MIC was found at the 20th hr and 24th hr of incubation. Ecotoxicology and histopathology trials on snails showed mild changes in MICs of the preparations. The study thus concluded increasing drug resistance in E. coli of houbara bird while sodium alginate stabilized MgO nanoparticles and antibiotics were effective alternative antibacterial composites with mild toxicity.

Acaricidal Potential and Ecotoxicity of Metallic Nano-Pesticides Used against the Major Life Stages of Hyalomma Ticks.

Ticks (Acari: Ixodidae) are blood-feeding parasites capable of transmitting diseases to animals (Piroplasmosis) and humans (Congo fever, Lyme disease). The non-judicious use of chemical acaricides has led to the development of acaricide-resistant ticks, making the control of ticks and tick-borne diseases difficult. This study reports the efficacy of magnesium oxide (MgO), iron oxide (Fe2O3), and zinc oxide (ZnO) nanoparticles (NPs) as alternatives to traditional acaricides/pesticides using in vitro tests against major representative stages of Hyalomma ticks. Nanopesticides were chemically synthesized as rods (Fe2O3), stars (ZnO), and spheres (MgO) and were characterized by XRD and SEM analysis. The in vitro bioassays included adult immersion, larval immersion, and larval packet tests. Non-target effects of the nanopesticides were evaluated using snails. The LC90 values of Fe2O3 NPs (4.21, 2.83, 0.89 mg/L) were lowest followed by MgO (4.27, 2.91, 0.93 mg/L) and ZnO (4.49, 3.05, 0.69 mg/L), for the tick adult, larval and egg stages, respectively. Fe2O3 NPs were capable of arresting oviposition and larval hatching in the study ticks in vitro. The snail toxicity experiments revealed minimum to mild off-target effects for all nanopesticides tested. This study is the first to report the comparative efficacy of magnesium, iron, and zinc nanomaterials for toxicity in egg, adult and larval stages of Hyalomma ticks. Further studies of NPs on establishing the efficacy against ticks and safety at host-human-environment interface could lead to promising nanopesticde applications.

Bringing resistance modulation to epidemic methicillin resistant S. aureus of dairy through antibiotics coupled metallic oxide nanoparticles.

The current study probed methicillin resistant S. aureus from milk of different dairy farms along with its response to multiple antibiotics, assessment of risk factors, and response to antibiotic coupled nanoparticle. XRD of Np was confirmed as miller indices (hkl) values i.e. (101), (100), (002), (110), (012) and (013) while STEM finally revealed 40-60 nm nanorods in aggregated form. Total of 6 preparations viz a viz gentamicin (G), chloramphenicol (C), zinc oxide nanoparticle (Np), gentamicin coupled Np (GNp), chloramphenicol coupled Np (CNp), and simultaneously coupling of gentamicin and chloramphenicol on Np (GCNp) were formulated for their potential to bring resistance modulation. Data analysis of this study revealed 24.59% MRSA from dairy milk appearing potentially associated (OR> 1, p < 0.05) with most of assumed risk factors. MRSA in response to various antibiotics showed highest resistance against amoxicillin (100%), penicillin (100%), vancomycin (100%), and linezolid (90%). Zone of inhibitions were increased by 249.76% (GNp), 184.86% (CNp), and 279.76% (GCNp) in case of coupled preparations. Significant reduced minimum inhibitory concentration was observed in case of GCNp (7.8125 ± 0.00 µg/mL) followed by GNp (15.00 ± 0.00 µg/mL) and CNp (41.67 ± 18.042 µg/mL) as compared to Np alone (125.00 ± 0.00 µg/mL). Minimum bactericidal concentrations for GCNp, GNp, and CNp, and Np were 31.125, 62.5, 125, and 500 µg/mL, respectively. The study thus concluded increased prevalence of MRSA while coupling of ZnO nanoparticles with antibiotics significantly brought resistance modulation to MRSA.

Synthesis of manganese-tin oxide microparticles by the solvothermal method and study of application as a catalyst and additive.

Manganese-tin bimetallic oxide (MnSnO3) is synthesized by the solvothermal approach using manganese acetate and stannic chloride as precursors and urea as a precipitating agent in an aqueous medium. The crystallinity, purity and lattice parameters of the product are analysed by the X-ray diffraction analysis. The morphology of the product is analysed with the help of a scanning electron microscopy. The synthesized product is used as a fuel additive and catalyst. Synthesized MnSnO3 is used as a catalyst for the degradation of an organic dye Congo red in the aqueous medium. Catalytic degradation is monitored at different concentrations of the catalyst and hydrogen peroxide. Moreover, the role of MnSnO3, as an additive in diesel fuel, is studied. The efficiency of the modified fuel is analysed by studying the different parameters such as flash point, fire point, cloud point, pour point, calorific values and specific gravity. The values of these parameters change significantly by changing the dosage of the additive.

Antimicrobial resistance modulation of MDR E. coli by antibiotic coated ZnO nanoparticles.

We evaluated three types of total six preparations against multidrug resistant E. coli i) three antibiotic coated ZnO nanoparticles (gentamicin coated nanoparticle-GNp; chloramphenicol coated nanoparticles-CNp; and both gentamicin & chloramphenicol coated nanoparticle-GCNp), ii) ZnO nanoparticle alone-Np, and iii) two antibiotics used in single (Gentamicin-G; and Chloramphenicol-C). A total of n = 200 sub-clinically positive mastitic milk samples of bovine origin were processed for isolation of MDR E. coli using microbiological and clinical laboratory & standard institute's protocols. ZnO Nps were prepared from zinc acetate dihydrate (Zn (CH3COO)2. 2H2O), polyethylene glycol (C2nH4n+2On+1), and urea (CH4N2O) by standard chemical protocol. Nps were characterized by XRD and STEM analyses while coating of antibiotics on Nps was confirmed by UV-Visible spectrophotometric analysis. Analysis of variance and student t-test were applied at 5% probability using SPSS version 22 statistical software for inferences on obtained data. There was significantly (p < 0.05) lowest minimum inhibitory concentrations (MICs) and highest zone of inhibitions (ZOIs) in case of GCNp (10.42 ± 4.51 µg/mL & 22.00 ± 1.00 mm) followed by GNp (20.79 ± 8.95 µg/mL & 20.00 ± 1.00 mm) and then CNp (25.96 ± 8.95 µg/mL & 12.33 ± 0.57 mm). Percentage increase in ZOI were expressed as 135.8, 78.43, and 312.76% by GCNp when compared with that of G, C, and Np, respectively. GNp and CNp coated preparations exhibited 114.36 and 275.73% increase in ZOI than to that of G and C, respectively. Similar trend was found in percentage reduction of MICs of preparations. Highest filamentation, indicator of bacterial damage, of E. coli was noted at MIC of GCNp followed by GNp and CNp. The study concluded antibiotic coated ZnO nanoparticles significant candidates modulating antibiotic resistance in MDR E. coli.

The effect of different aromatic conjugated bridges on optoelectronic properties of diketopyrrolopyrrole-based donor materials for organic photovoltaics.

A series of twelve Acceptor-π-Donor-π-Acceptor (A-π-D-π-A) topology-based donor molecules, where diketopyrrolopyrrole (DPP) as donor core unit is connected through furan which acts as conjugated π-bridge (CB) to aromatic derivatives (Ar) as acceptor units, have been investigated by making substitutions in acceptor units by using density functional theory(DFT) and time-dependent density functional theory (TD-DFT) for organic solar cell applications. The comparative study of optoelectronic properties indicates that thiadiazole with pyridine units containing molecules (M6b) exhibit lower energy of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels than those of oxadiazole and pyridine containing units (M6b). Among our investigated donors, the smallest Eg of 1.60 eV was observed for both M6a and M6b with distinctive broad absorption at 843 and 857 nm, respectively. Overall, smaller electron transfer (λe) values in contrast to hole transfer (λh) demonstrate that these donor compounds would be best for λe. The calculated open circuit voltage (Voc) is 2.45 and 2.17 eV, regarding bisPCBM and PC60BM (phenyl-C61-butyric acid methyl ester) acceptors. Thus, these theoretical calculations not only endorse the deep consideration between the chemical structures and optoelectronic characteristics of the donor-acceptor systems but also suggest appropriate materials for high-performance Organic Photovoltaics (OPV). Graphical abstract.

Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods.

A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO2) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO2 microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H2O2) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.

The first morphologically controlled synthesis of a nanocomposite of graphene oxide with cobalt tin oxide nanoparticles.

In the present research, the degradation and decolorization of Reactive Black 5 synthetic dye at 30 ppm concentration under sun irradiation in the presence of a newly synthesized graphene based cobalt tin oxide nanocomposite were investigated. These nanoparticles were synthesized by a simple hydrothermal approach using precursor chloride salt i.e., stannous chloride and cobalt chloride and then adsorbed on the surface of RGO by a solvothermal process by changing the condition. The newly synthesized product was subjected to various instrumentation to study the morphology and other properties. X-ray powder diffraction analysis (XRD) explained the structural composition and various parameters of the product, which were further verified by Vesta software. The surface morphology of the product was analyzed by scanning electron microscopy (SEM) and it was observed that the size of each cube was approximately 5-10 µm from every face of the cube. Transmission electron microscopy (TEM) explained that the nanoparticles were within the range of 100-250 nm. These synthesized nanocubes were used in one more application, which was the investigation of the fuel efficiency in the presence of different concentrations of newly synthesized nanocomposites as a catalyst. The efficiency of kerosene oil was investigated by studying different parameters: the flash point, fire point, specific gravity, cloud point, pour point, and calorific value at increasing dosages of catalyst (0, 30, 60 and 90 ppm). It was observed that the values of these parameters changed significantly by changing the concentration of the catalyst dosage. The effect of the nanoparticles on the degradation of the RB 5 azo dye showed the highest removal percentage at the largest value of catalyst dosage, which was 0.70 mg ml-1 with the highest value of 3 ml of hydrogen peroxide.

Morphologically controlled synthesis of ferric oxide nano/micro particles and their catalytic application in dry and wet media: a new approach.

Morphologically controlled synthesis of ferric oxide nano/micro particles has been carried out by using solvothermal route. Structural characterization displays that the predominant morphologies are porous hollow spheres, microspheres, micro rectangular platelets, octahedral and irregular shaped particles. It is also observed that solvent has significant effect on morphology such as shape and size of the particles. All the morphologies obtained by using different solvents are nearly uniform with narrow size distribution range. The values of full width at half maxima (FWHM) of all the products were calculated to compare their size distribution. The FWHM value varies with size of the particles for example small size particles show polydispersity whereas large size particles have shown monodispersity. The size of particles increases with decrease in polarity of the solvent whereas their shape changes from spherical to rectangular/irregular with decrease in polarity of the solvent. The catalytic activities of all the products were investigated for both dry and wet processes such as thermal decomposition of ammonium per chlorate (AP) and reduction of 4-nitrophenol in aqueous media. The results indicate that each product has a tendency to act as a catalyst. The porous hollow spheres decrease the thermal decomposition temperature of AP by 140 °C and octahedral Fe3O4 particles decrease the decomposition temperature by 30 °C. The value of apparent rate constant (kapp) of reduction of 4-NP has also been calculated.