Pd-MnO_2 nanoparticles/TiO_2 nanotube arrays(NTAs) photo-electrodes photo-catalytic properties and their ability of degrading Rhodamine B under visible light

Pd-MnO2/TiO2 nanotube arrays（NTAs） photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO2/TiO2 NTAs photo electrodes were analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and characterized accordingly. Moreover, the light harvesting and absorption properties were investigated via ultraviolet–visible diffuse reflectance spectrum（DRS）; photo degradation efficiency was investigated via analyzing the photo catalytic degradation of Rhodamine B under visible illumination（xenon light）. The performed analyses illustrated that Pd-MnO2 codoped particles were successfully deposited onto the surface of the TiO2 nanotube arrays;DRS results showed significant improvement in visible light absorption which was between400 and 700 nm. Finally, the photo catalytic degradation efficiency results of the designated organic pollutant（Rhodamine B） illustrated a superior photocatalytic（PC） efficiency of approximately 95% compared to the bare TiO2 NTAs, which only exhibited a photo catalytic degradation efficiency of approximately 61%, thus it indicated the significant enhancement of the light absorption properties of fabricated photo electrodes and their yield of UOH radicals.

Sonochemical synthesis and characterization of magnetic separable Fe_(3)O_(4)-TiO_(2)nanocomposites and their catalytic properties

A novel sonochemical method is described for the preparation of Fe_(3)O_(4)–TiO_(2)photocatalysts in which nanocrystalline titanium dioxide particles are directly coated onto a magnetic core.The Fe_(3)O_(4)nanoparticles were partially embedded in TiO_(2)agglomerates.TiO_(2)nanocrystallites were obtained by hydrolysis and condensation of titanium tetraisopropyl in the presence of ethanol and water under high-intensity ultrasound irradiation.This method is attractive since it eliminated the high-temperature heat treatment required in the conventional sol–gel method,which is important in transforming amorphous titanium dioxide into a photoactive crystalline phase.In comparison to other methods,the developed method is simple,mild,green and efficient.The magnetization hysteresis loop for Fe_(3)O_(4)–TiO_(2)nanocomposites indicates that the hybrid catalyst shows superparamagnetic characteristics at room temperature.Photocatalytic activity studies confirmed that the as-prepared nanocomposites have high photocatalytic ability toward the photodegradation of RhB solution.Furthermore,the photodecomposition rate decreases only slightly after six cycles of the photocatalysis experiment.Thus,these Fe_(3)O_(4)–TiO_(2)nanocomposites can be served as an effective and conveniently recyclable photocatalyst.

Characterization and photocatalytic properties of silver and silver chloride doped TiO_2 hollow nanoparticles

Using polystyrene （PSt） particles as template, PSt/TiO2 composite particles with AgCl incorporation were prepared through hydrolysis of tetrabutyl titanate in the presence of AgNO3 and NaCl. AgCl doped TiO2 hollow particles were successfully prepared with the PSt/TiO2 composite microspheres pretreated at 180 ℃ followed by calcination. The morphology of PSt/TiO2 particles and the crystal structures of the AgCl doped TiO2 hollow particles were characterized. The photocatalytic activity of the doped TiO2 hollow particles in degradation of Rhodamine B was tested under UV and visible lights and compared to that with Ag doped TiO2 particles. The results showed that TiO2 hollow particles, either doped with Ag or AgCl, demonstrated higher photocatalytic activity than the pure TiO2 particles. This enhancement in photocatalytic activity was more significant with AgCl doped TiO2 than that with Ag doped, and more distinct when the degradation was done under visible light than that under UV light.