Synthesis of Mn(II)-Loaded TixSi1-xO4 Composite Acting as a Visible-Light Driven Photocatalyst

The synthesis and characterization of Mn-loaded TixSi1-xO4 (x= 0.4-0.8) composites and a preliminary study of an activity testing their ability to work as photocatalysts for the degradation of methylene blue (MB) have been studied. Synthesis was conducted by the sol-gel method at room temperature using tetraethyl orthosilicate, titanium tetraisopropoxide, and manganese(II) chloride as precursors followed by thermal treatment at 500 °C. The characterizations were performed by X-ray diffraction, FT-IR spectrometry, UV-Vis diffuse reflectance spectrometry and a surface area analyzer. The photocatalytic activity test of composites for degradation of MB was carried out in a closed reactor equipped with UV and visible lights. In this test, the effects of ratio of Ti/Si composites, Mn2+ ion concentration, pH, and time of irradiation on the effectiveness of photodegradation of MB were studied. The results indicated that Mn-Ti0.6Si0.4O4 composite could be synthesized through the sol-gel method followed by thermal treatment with a molar ratio of Ti/Si=60/40 and the optimum concentration of manganese was 2.5 wt%. The Mn-Ti0.6Si0.4O4 composite significantly increased the photodegradation of MB at pH 10, with a percent degradation of 84.41% for 30 min under irradiation of visible light. The percent degradation of Ti0.6Si0.4O4 was only 18.23% under irradiation of visible light.

The Hydrothermal Synthesis of β-ZnMoO4 for UV or Visible-Light-Responsive Photocatalytic Dedradation of Victoria Blue R

In this study, hydrothermal reaction with Na2MoO4 and Zn(NO3)2as a precursor were investigated for the synthesis of β-ZnMoO4. The β-ZnMoO4were characterized by the X-ray diffractometer (XRD), electron microscopy with the field emission scanning electron microscopy with energy dispersive X-ray spectrometer (FE-SEM-EDS), high resolution X-ray photoelectron spectrometry (HR-XPS), UV-vis diffuse reflectance spectrometry (UV-DRS), and Fourier transform infrared spectrometry (FT-IR). Diffuse UV-vis spectra show the β-ZnMoO4materials to be indirect semiconductors with an optical bandgap of 2.48-2.64 eV. The photocatalytic efficiencies of powder suspensions were evaluated by measuring the Victoria Blue R (VBR) concentration. This is the first reveal that excellent activities of β-ZnMoO4are a promising visible-light-responsive photocatalyst.

Preparation and Characterization of Nitrogen-Doped TiO2 Decorated with Different Metal Ion

In this paper, nanotubular TiO2 obtained by hydrothermal method was selected as precursor to prepare metal ion decorated TiO2-xNxvia a facile and one-pot method. As-synthesized M/TiO2-xNx (M references to Pd, Fe, Ni, Li) photocatalysts were characterized by means of X-ray diffraction, diffuse reflectance spectrometry, fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of different metal ion decorated TiO2-xNx samples were compared by monitoring the photocatalytic oxidation of propylene under both ultraviolet light (UV) and visible light (Vis) irradiation. It was found that Pd/TiO2-xNx sample possessed the highest photocatalytic activity under both UV and Vis irradiation. The better crystallinity, better visible light absorption, higher hydroxy concentration were contributed to the best photocatalytic performance of Pd/TiO2-xNx.