Magnetically separable silica-coated cobalt ferrite (CoFe2O4@SiO2) magnetic nanoparticles (MNPs) were synthesized by sol-gel auto combustion method. Silica matrix was employed to minimize the agglomeration and coarsening of the MNPs. The structural and morphological properties of the as-prepared nanocatalyst were investigated using XRD, EDX, TEM-SAED, FTIR, XPS and VSM techniques. Furthermore, these nanoparticles were used as an efficient nanocatalyst for simple, swift and one-pot synthesis of 5-aryl-1,2,4-triazolidine-3-thione derivatives. The reaction steps include imine formation, cyclization, condensation and aromatization without use of any oxidizing or reducing reagents. The present methodology offers remarkable merits like shorter reaction time, mild reaction conditions, excellent yield, simplicity, safer reaction pathway, easy workup and recyclable catalyst without any significant loss in catalytic activity and can be used for large scale synthesis. Hence, the present study describing the synthesis of CoFe2O4@SiO2 nanoparticles by efficient sol-gel auto combustion method followed by the investigation of potent catalytic activities may be useful for nanochemistry research opening a new arena in this field.

In this work, we studied the effect of various amounts (0.2-1.2 % mole ratio) of Cu doping to TiO2 nanoparticles (Cu/TiO2) on the photocatalytic removal efficiency of the food colorant E 131 VF. Two series of doped TiO2 (P25) photocatalysts were prepared in two different media (50%ethanol-50%acetone and 5% surfactant (Tween 20)-95%H2O) by using the impregnation method. The prepared samples were characterized by XRD, FTIR, Raman, diffuse reflectance spectroscopy and SEM/EDX analyses. The XRD results showed that the crystal dimension of TiO2 increased from 23 to 35 nm and rutile/anatase ratio decreased from 16% to 9% after Cu doping in two different media. The photoactivity of TiO2 was reduced in the presence of Cu even at low molar ratio. The photocatalytic degradation rate constant of TiO2 (P25) was 0.24 (au) but it decreased to 0.015 (au) in the presence of the sample containing 0.6% Cu. Several reasons were suggested to explain the dramatic decrease in the activity of the prepared Cu/TiO2samples.

In this study, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT as a new magnetic nanophotocatalytic materials were synthesized. For this, TiO2 nanoparticle were fixed on an inert surface by sonochemical method. X-ray Diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), vibration sample magnetometry (VSM) were used to characterize the magnetic nanocomposites. SEM analysis indicated that TiO2 and Fe3O4 nanoparticles were adhered to MWCNT. Ability of the nanocomposites to remove organic pollutants were investigated by photodegradation of Acid Red 14, Acid Blue 19, Reactive Red 77, and Methyl Orange dyes simulated conditions similar to sunlight. Furthermore, the removal efficiency of AR14 were investigated under direct sunlight irradiation, with an initial concentration of 50 mg/L by TiO2, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT nanocatalysts were 89.83, 21.19 and 86.27, respectively. According to the results, addition of carbon nanotubes to the TiO2/Fe3O4 magnetic nanocomposite, increased the efficiency of AR14 photodegradtion through change in energy gap visible waves and the scavenging role of carbon nanotubes. Also, The reusability of nanocomposites was assessed in five consecutive cycles of 6 hours, The results showed that after 5 cycles the degradation rate decreased only 7.79 %.

In this study, polysulfone (PSf) nanocomposite membranes embedded with functionalized nanodiamond (ND) were prepared via Non-Solvent Induced Phase Separation (NIPS) method. ND nanoparticles were silanized by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution in order to enhance the compatibility between ND and PSf. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that ND nanoparticles were successfully functionalized by silane groups. Nanocomposite membranes were then prepared with different percentages of silanized NDs (SNDs). The membranes were characterized using a set of analyses and the results showed that the addition of SNDs up to 1.0 wt.% resulted in an increase in hydrophilicity, water content, porosity and water flux of membranes. Moreover, Scanning Electron Microscopy (SEM) images indicated that the membrane with 1.0 wt. % nanoparticles had more pores on the membrane surface with smaller average pore size in comparison to other membranes. Antifouling properties of the membrane was also investigated in filtration of humic acid solution and the results showed that reversible fouling and flux recovery of membranes increased at the presence of SNDs.

Pharmaceutical wastewaters have several negative effects on human health. This study reports heterogeneous and ultrasound assisted electro Fenton (HSEF) for efficient degradation of Phenazopyridine (PHP). The high silica zeolite socony mobil–5 (ZSM-5) nanocatalyst is synthesized by hydrothermal technique and impregnated with iron species (0.1Fe-ZSM-5). The surface and textural properties of the synthesized nanocatalyst were characterized by X-ray Diffraction (XRD), Transmission electron Microscopy (TEM) and N2 adsorption-desorption techniques. The nanocatalyst includes the high crystallinity (ca. 72.41 %), surface area (ca. 294.40 m2g-1) and uniform dispersion of Fe species. The optimum operating conditions of the HSEF system are pH= 7, applied current of 100 mA, 0.1Fe-ZSM-5 nanocatalyst concentration of 0.2 gL-1 and ultrasonic power of 600 WL-1 which result in the highest PHP removal efficiency. The high performance of the developed nanocatalyst in three consecutive runs confirms the reusability of the nanocatalyst. The results show that the HSEF system has a high capacity for the efficient removal of PHP without requiring long reaction time, high applied current and strict acidic conditions which candidates it for the industrial applications.

This study was conducted to evaluate sodium dodecyl benzene sulfonate removal using electrocoagulation/flotation and photocatalytic nano-TiO2 slurry systems. The parameters which are effective on the surfactant removal were investigated and optimized. Electrocoagulation/flotation system included meshed and mono-polar stainless steel electrodes which installed horizontally. According to the results, after 60 minutes in pH of 8, electrodes distance of 1 cm, initial SDBS concentration of 750 mg/L, SDBS and COD removal rates were achieved to 93.54 and 90%, respectively. In photocatalytic system, during 48 h, SDBS and COD removed 98.7 and 95%, respectively, while pH was around 8, initial concentration of SDBS was 300 mg/L and nano-TiO2 particles concentration was 0.5 mg/L. In the hybrid system, after 12 minutes, SDBS concentration reached to 329 mg/L which entered to the photocatalytic system that resulted in SDBS and COD removal efficiency of 99 and 96.27%, respectively. Compared to the single systems, by using the hybrid system, the removal efficiencies were improved.

The electrochemical property of a recently synthesized ligand, 3-((3-mercaptophenyl) aminomethyl)benzene-1,2-diol has been investigated with construction of a modified carbon paste electrode to find out of mercury ions in real samples. To modify the electrode, paraffin oil and multi-walled carbon nanotubes (MWCNT) were used as binder and modifier respectively. Under the optimized conditions, the electrode exhibits a Nernstian slope of 30.0±0.2 mV per decade for mercury(II) ions over a broad concentration range 1×10-7 to 1×10-1M with a R2 value of 0.996 at pH 4.5 in a 5 sec response time. The detection limit of the method for Hg2+ was 2.3×10-8 mol l-1. The influence of several potentially interfering ions such as K+, Ag+, Cd2+, Ni2+, Ca2+, Cr3+, Pb2+, Cu2+, Co2+, Mg2+, Fe2+, Al3+, La3+ and Fe3+ on the determination of Hg2+ was studied and no significant interference was observed. The proposed modified carbon paste electrode was successfully applied to the determination of mercury ions in real water samples.

ZnO and 2%Fe-ZnO nanomaterials were prepared by using a low-cost sol-gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials have a hexagonal wurtzite structure with average crystalline size ~ 22-23 nm. EDX analysis confirmed the composition and purity of synthesized nanomaterial. The photocatalytic activity of synthesized nanomaterials was monitored using the spectrophotometric method. Also, the photocatalytic removal of methylene blue (MB) dye from its aqueous solution by using ZnO and 2%Fe-ZnO nanopowder under UV light irradiation was studied. The effect of various parameters such as pH of dye solution, dye concentration, contact time and catalyst dose were investigated. Results of the current study demonstrated that, the maximum degradation using ZnO was 86 % and that for 2%Fe-ZnO was 92 % (under the optimum condition initial dye concentration=10 mg/L and pH =2). This study showed that 2%Fe-ZnO is a promising and better photocatalysts than ZnO.