استكشف المجموعة الواسعة من العناوين المتاحة.

In this work, Titania was modified by sulfation or fluorination and platinum on the surface to improve the Cr (VI) reduction efficiency compared to the bare TiO2 material synthesized by the sol-gel method. The synthesized materials were characterized by XRD, SBET, UV-Vis DRS, XRF, TEM, FTIR, and XPS. The modifications led to higher stability in the Anatase phase and surface area of this semiconductor. The addition of F and Pt in TiO2 led to absorption increases in the visible region of the electromagnetic spectrum. A correlation between the new physicochemical properties obtained after TiO2 modification and the photocatalytic performance of this material was observed. The best result in chromium reduction was obtained using Pt-S-TiO2 as the photocatalyst; this material showed a suitable combination of surface area, high UV-Vis absorption, high hydroxylation, and the existence of Pt nanoparticles on the surface, which favors an increased electron-hole pair half-life. Different reaction parameters were also evaluated, which demonstrated that the best photocatalytic performance was obtained under an N2 atmosphere, a light intensity of 120 W/m2, and 2 hours of total reaction time. Likewise, it was noted that an increase in reaction time from 2 to 5 hours, had a detrimental effect on reducing Cr (VI) efficiency.

A sulfur nanoparticles-incorporated iron-doped titanium oxide (Fe/TiO 2 ) with different ratio was successfully synthesized by photolysis method and utilized as effective photoanode in dye sensitized solar cell (DSSC) application with N719 dye. The photolysis method was contained the irradiation of the Fe, S and Ti mixture solution with 15 W source irradiation, and then calcined the formed precipitate. The DSSCs fabricated with Fe/S–TiO 2 photoanode appeared an improved solar-to-electrical energy conversion efficiency of 6.46, which more than pure TiO 2 (3.43) below full sunlight illumination (1.5 G). The impact of Fe content on the total efficiency was also inspected and the Fe content with 6% S–TiO 2 was found 5 wt%. Due to the improved the efficiency of solar cell conversion of Fe/S–TiO 2 nanocomposite, it should be deemed as a potential photoanode for DSSCs with high performance.

In this work, Titania was modified by sulfation or fluorination and platinum on the surface to improve the Cr (VI) reduction efficiency compared to the bare TiO2 material synthesized by the sol-gel method. The synthesized materials were characterized by XRD, SBET, UV-Vis DRS, XRF, TEM, FTIR, and XPS. The modifications led to higher stability in the Anatase phase and surface area of this semiconductor. The addition of F and Pt in TiO2 led to absorption increases in the visible region of the electromagnetic spectrum. A correlation between the new physicochemical properties obtained after TiO2 modification and the photocatalytic performance of this material was observed. The best result in chromium reduction was obtained using Pt-S-TiO2 as the photocatalyst; this material showed a suitable combination of surface area, high UV-Vis absorption, high hydroxylation, and the existence of Pt nanoparticles on the surface, which favors an increased electron-hole pair half-life. Different reaction parameters were also evaluated, which demonstrated that the best photocatalytic performance was obtained under an N2 atmosphere, a light intensity of 120 W/m2, and 2 hours of total reaction time. Likewise, it was noted that an increase in reaction time from 2 to 5 hours, had a detrimental effect on reducing Cr (VI) efficiency.

Pt-TiO2 and Au-TiO2 photocatalysts were prepared by noble metalphotodeposition on sulfated TiO2. It was observed that optical absorption, oxidation state andparticle size of the metallic species (Pt or Au) play an important role in the TiO2 photocatalyticactivity under visible-light irradiation. Photocatalytic activity of the bare TiO2 powder in thephenol and methyl orange degradation increased with the sulfation and metal addition.The highest degradation rate under UV-Visible and visible light irradiation was obtained onPt-S-TiO2 photocatalyst; this is mainly due to the optical properties of TiO2 induced byplatinization and also to the good distribution and low Pt particles size. It was also found thatthis catalyst has a good stability after two cycles of reaction in the phenol photodegradationunder UV-Visible light irradiation. The Pt-S-TiO2 photocatalyst was also active under solarlight and under the environmental conditions of the city of Tunja (Boyacá), Colombia.

Sulfur/lithium battery performances are strictly related to the morphology and nanostructure of sulfur particles. In this work, a comparison of the morphological characteristics and electrochemical properties of electrodes based on colloidal sulfur (CS) obtained by means of traditional chemical precipitation from aqueous solution and via spinning disk reactor (SDR) has been performed. In particular, through the SDR technique and by using different fluid dynamic conditions, it was possible to obtain monodisperse and nanometricsulfurparticles with higher electrochemical performances when used as the cathodic active material in lithium batteries. Moreover, a method to produce core–shell nanoparticles with sulfur and titanium dioxide, starting from a colloidal sulfur (S8) solution and produced by SDR, has been performed, obtaining good electrochemical results. In particular, the nanometric sulfur powder produced by the SDR technique showed a capacity higher than CS after 100 cycles, even if the capacity decreased rapidly in both cases. Instead, considering the core–shell S–TiO2 material, the nanostructured electrode allowed a wide use of active material and a reduced capacity decay during cycling. Specifically, the material showed an initial capacity of 1395 mAh/g, i.e., representing 83% of the theoretical value, which decreased during operation up to 450 mAh/g after about 30 cycles. Then, the material capacity remained unchanged and no substantial loss of capacity was recorded up to 100th cycle.