Platinum-Decorated TiO2: One Step Fast Monometallic Impregnation and Plasma Effect on Nanoparticles

In the present work, N-TiO2−x/Pt was synthesized using a homemade nitrogen plasma (AC) discharge system. The overall procedure use of low-power nitrogen plasma (100 watts) with 1 and 2 h of plasma discharge to successfully impregnate platinum nanoparticles on P25 titanium dioxide. The obtained samples were characterized using X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The results reveal the incorporation of metallic Pt up to 2.9% on the surface of TiO2 by increasing the duration of plasma discharge by up to two hours with a constant power of 100 watts. Likewise, the incorporation of nitrogen atoms into a lattice crystal was also favored, confirming a direct relationship between the amount of Pt and nitrogen atoms introduced in TiO2 as a function of the duration of plasma treatment. By characterizing nanoparticles loaded on a N-TiO2−x/Pt surface, we show that joined platinum nanoparticles have two different patterns, and the boundary between these two regions coalesces. The results demonstrate that the use of nitrogen plasma to impregnate platinum nanoparticles on the surface of TiO2 to obtain N-TiO2−x/Pt allows wide and relevant physics and chemistry applications

Platinum-Decorated TiO₂: One Step Fast Monometallic Impregnation and Plasma Effect on Nanoparticles

In the present work, N-TiO2−x/Pt was synthesized using a homemade nitrogen plasma (AC) discharge system. The overall procedure use of low-power nitrogen plasma (100 watts) with 1 and 2 h of plasma discharge to successfully impregnate platinum nanoparticles on P25 titanium dioxide. The obtained samples were characterized using X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The results reveal the incorporation of metallic Pt up to 2.9% on the surface of TiO2 by increasing the duration of plasma discharge by up to two hours with a constant power of 100 watts. Likewise, the incorporation of nitrogen atoms into a lattice crystal was also favored, confirming a direct relationship between the amount of Pt and nitrogen atoms introduced in TiO2 as a function of the duration of plasma treatment. By characterizing nanoparticles loaded on a N-TiO2−x/Pt surface, we show that joined platinum nanoparticles have two different patterns, and the boundary between these two regions coalesces. The results demonstrate that the use of nitrogen plasma to impregnate platinum nanoparticles on the surface of TiO2 to obtain N-TiO2−x/Pt allows wide and relevant physics and chemistry applications

Effects of UV-Vis Irradiation on Vanadium Etioporphyrins Extracted from Crude Oil and the Role of Nanostructured Titania

The role of UV-irradiation on oil and its derivatives is particularly important for analyzing the degradability of specific oil compounds. Also, nanostructured-TiO2 is one of the most promising photocatalysts so it is expected to be useful in their degradation. However the complexity of crude oil, as well as that of the reactions involved, is such that the effect of the presence of TiO2 under illumination is not well understood. In this paper, the influence of UV-Vis irradiation on vanadium etioporphyrins, extracted from crude oil from Dos Bocas, Tabasco, Mexico, is studied using UV-Vis spectrophotometry in the absence and presence of nanostructured TiO2 or nitrogen-doped TiO2 modified with copper (N-TiO2/Cu). It is shown that the addition of water shortens the time to start photodegradation. However, once this process has initiated, the system enters a second stage, that is very similar for samples with or without water. It is also shown that the use of N-TiO2/Cu induces an important delay in the initiation of the porphyrins’ photodegradation process. Additionally, it has been found that the presence of TiO2 in samples extracted with water induces a small reduction in the photodegradation duration and, hence, that TiO2 can catalyze the degradation of petroporphyrins

The effects of metal doped TiO2 and dithizone-metal complexes on DSSCs performance

Different metal (Fe, Ni, Co or Zn) doped TiO2 nanoparticles and dithizone-metal (Fe, Ni, Co or Zn)-gallic acid complexes were prepared and used in dye sensitized solar cells (DSSCs). The TiO2 and metal doped TiO2 nanoparticles were synthesized by microwave assisted hydrothermal method. Synthesized TiO2 nanoparticles were characterized with SEM, EDS, XRD and DRS. Prepared dithizone-metal-gallic acid complexes were characterized via UV-Vis and FTIR techniques. Photoanode of DSSC was prepared with TiO2 or metal doped TiO2 coating on FTO-glass using spin coater. The dithizone and dithizone-metal-gallic acid complexes were adsorbed on bare TiO2, and dithizone or N719 were adsorbed on metal doped TiO2. Then, sandwich type DSSCs were prepared and electrochemical characterization of DSSCs was made. When the N719 and dithizone sensitized metal doped TiO2 nanoparticles were compared with undoped TiO2, Fe doped TiO2 gave lower efficiency, Ni, Co and Zn doped TiO2 gave higher efficiency than that of undoped TiO2. Co doped samples showed the highest efficiencies with both N719 and dithizone. Co doped TiO2 which was sensitized with dithizone gave nearly three times more conversion efficiency than undoped TiO2. These results show that doping procedure can enhance binding dyes to semi conductor surface. In summary, various metals show different characteristics when doped to TiO2 nanoparticles