Nickel ferrite/multi-walled carbon nanotubes (NiFe2O4/MWCNTs) composite has been rapidly synthesized via microwave irradiation technique. The structural properties of the product was investigated by X-ray diffraction (XRD), N2 adsorption/desorption isotherms, thermogravimetric analysis (TGA), Raman spectroscopy and, scanning electron microscopy (SEM). Catalytic behavior of the composite material on the advanced photo-Fenton degradation of Amaranth dye was evaluated. The synthesis conditions employed on the microwave system were: temperature (235 °C), power (500 W), pressure (600 psi) and irradiation time (30 min). Characterization results showed the formation of hybrid material, containing a predominantly microporous structure, with surface area and total pore volume of 54 m2 g-1 and 0.2249 cm3 g-1, respectively. The composite exhibited higher catalytic activity compared to the pure NiFe2O4, reaching 100% of decolorization at 60 min of reaction, which can be attributed to a synergism between NiFe2O4 and MWCNTs. Therefore, NiFe2O4/MWCNTs composite can be used as a promising photo-Fenton catalyst to degrade Amaranth dye from aqueous solutions.

ZnWO4 particles were synthesized as a single-phase by a simple and easy solvo-hydrothermal technique using water-ethylene glycol mixture as solvent, without using surfactant. Physical properties of produced particles were analyzed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), surface area (BET), particles size distribution and atomic force microscopy (AFM). This material was used as support for inulinase immobilization by physical adsorption and the influence of temperature (30 and 50 ºC) was evaluated. Material with mesoporous characteristic and with a surface area of 35.5 m2.g-1 was obtained. According to the findings, ZnWO4 present a satisfactory inulinase adsorption, and the better result was 605 U.g-1 support at 30 ºC. Therefore, ZnWO4 particles prepared by one-step solvo/hydrothermal route provide a new potential support for inulinase immobilization.

ZnAl2O4 spinel was synthesized by co-precipitation using ammonia as precipitating agent, followed by thermal treatment at 750 ºC. The structural properties of particles were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), differential thermal analysis (DTA), and N2 adsorption/desorption isotherms (BET) techniques. The photocatalytic activity was evaluated in the degradation of organic pollutant in aqueous solution under sunlight. The results showed that the ZnAl2O4 particles exhibited a mesoporous structure, and a promising photocatalytic activity for the degradation of pollutant molecules.