Photocatalytic Degradation of Methyl Orange on Platinum and Palladium Co-doped TiO2 Nanoparticles

Catalytic applications of β-cyclodextrin/palladium nanoparticle thin film obtained from oil/water interface in the reduction of toxic nitrophenol compounds and the degradation of azo dyes

A supramolecular catalyst of Pd/β-cyclodextrin thin film is synthesized via a facile and one-pot procedure at an oil–water interface and applied for the reduction of toxic nitrophenol compounds and the degradation of harmful azo dyes.

Solar pyrolysis of waste rubber tires using photoactive catalysts

The solar pyrolysis of waste tire rubber was investigated with the application of heterogeneous photocatalysts including TiO₂, Pd/TiO₂, Pt/TiO₂, Pd-Pt/TiO₂, and Bi₂O₃/SiO₂/TiO₂. Experiments were performed at temperatures ranging between 550 and 570 °C under solar irradiations of 950-1050 W/m². The gas yield from non-catalytic solar pyrolysis was at 20% while the use of TiO₂ catalyst increased the gas yield to 27%. Doping of TiO₂ with noble metals and Bi₂O₃/SiO₂ metal oxides enhanced further the cracking ability of the catalyst. Bi₂O₃/SiO₂/TiO₂ gave a 32% gas yield. The highest gas yields of 40% and 41% were achieved over Pd-Pt/TiO₂ and Pd/TiO₂ catalysts, respectively. Catalyst characterization by BET, SEM, EDX and XRD showed the role of metal doping in altering the morphology of TiO₂, resulting in nanocrystallites, larger pore volume and higher surface area. Both, Pd and Bi influenced the photocatalytic properties of TiO₂ improving cracking activity during pyrolysis of waste rubber.

Combination of mesoporous titanium dioxide with MoS2 nanosheets for high photocatalytic activity

This study presents a facile approach for the preparation of MoS2 nanosheet decorated by porous titanium dioxide with effective photocatalytic activity. Mesoporous titanium dioxide nanostructures first synthesized by a hydrothermal process using titanium (III) chloride and then the MoS2/TiO2 were prepared through mixing of MoS2 nanosheet with mesoporous titanium dioxide under ultrasonic irradiation. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The results showed that the nanocomposite has mesoporous structure with specific surface area of 176.4 m2/g and pore diameter of 20 nm. The as-prepared MoS2/TiO2 nanocomposites exhibited outstanding photocatalytic activity for dye degradation under sunlight irradiation, which could be attributed to synergistic effect between the molybdenum disulfide nanosheet and mesoporous titanium dioxide. The photocatalytic performance achieved is about 2.2 times higher than that of mesoporous TiO2 alone. It is believed that the extended light absorption ability and the large specific surface area of the 2D MoS2 nanosheets in the nanocomposite, leading to the enhanced photocatalytic degradation activity.

Biosynthesis of titanium dioxide nanoparticles using Bacillus amyloliquefaciens culture and enhancement of its photocatalytic activity for the degradation of a sulfonated textile dye Reactive Red 31

The present study aims at exploiting Bacillus amyloliquefaciens for the biosynthesis of titanium dioxide nanoparticles and also investigates role of bacterial enzymes in the biosynthesis of titanium dioxide nanoparticles. Bacterial synthesized as well as metal doped titanium dioxide nanoparticles were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray spectroscopy (EDAX). Amylase activity (43.37IU) in culture supernatant evinced a potential involvement of extracellular enzyme in TiO2 nanoparticle biosynthesis. Crystallite size of bio-synthesized nanoparticles was found to be in the range of 15.23-87.6nm. FTIR spectroscopy and native-PAGE (Polyacrylamide Gel Electrophoresis) clearly indicated involvement of alpha amylase in biosynthesis of TiO2 nanoparticles and in their stabilization. TEM micrographs of the synthesized titanium dioxide nanoparticles revealed the formation of spherical nanoparticles with a size range of 22.11-97.28nm. Photocatalytic degradation of Reactive Red 31 (RR31) dye was carried out using bio-synthesized TiO2 nanoparticles under UV radiation. Photocatalytic activity of synthesized nanoparticles was enhanced by Ag, La, Zn and Pt doping. Platinum doped TiO2 showed highest potential (90.98%) in RR31 degradation as compared to undoped (75.83%).