Engineering of mono-dispersed mesoporous TiO2 over 1-D nanorods for water purification under visible light irradiation

Herein we synthesized a novel structure of mesoporous TiO₂ decorated on 1D ZnO nanorods for environmental remediation. The effect of mesoporous TiO₂ over 1D nanorods were investigated. The phase transitions of nanocomposite were confirmed by powder diffraction analysis. The morphological investigation of synthesized TiO₂/ZnO catalyst revealed that the TiO₂ are in porous in nature which covered the surface of 1D nanorods. The size of mesoporous TiO₂ nanoparticles was about 10-15 nm. The chemical composition and elemental mapping results clearly evident that the presence of ZnO and TiO₂ is distributed uniformly on ZnO nanorods. TiO₂/ZnO nanocomposite shows enhanced activity which degrades in 14 min under visible light irradiation. TiO₂/ZnO catalyst with 5 wt % exhibited the high photocatalytic activity (0.1882 min^-1). It is proposed that a synergistic interaction between ZnO and TiO₂ leads to a charge separation which leads to the enhanced activity.

Synthesis and adsorption behavior of hydroxypropyl-β-cyclodextrin-polyurethane magnetic nanoconjugates for crystal and methyl violet dyes removal from aqueous solutions

In this study, hydroxypropyl-β-cyclodextrin (HPβCD), HPβCD-conjugated magnetic nanoparticles (HPMN) and HPβCD-conjugated magnetic nanoparticles with polyurethane networks (HPMNPU) were synthesized and used as adsorbents for the removal of crystal violet (CV) and methyl violet (MV) dyes from aqueous solutions. Magnetic nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results of characterization analyses indicated that HPβCD was successfully modified with magnetic nanoparticles and polyurethane networks. In this work, a novel definitive screening design (DSD) was initially used to investigate the adsorption and elimination of dye impurities. This method allows a drastic reduction in the number of experiments needed to investigate those systems characterized by a large number of variables. The effects of nine quantitative parameters were investigated: initial dye concentration, adsorbent dose, contact time, temperature, pH, ionic strength, HMDI/HP ratio, MN/HP ratio, and stirrer speed. Analysis of a DSD model revealed that only four variables, namely, adsorbent dose, contact time, initial dye concentration and HMDI/HP ratio were statistically significant. Compared with HPMN, HPMNPU nanocomposites showed better adsorption performance for the removal of CV and MV from aqueous solutions. The maximum adsorption capacity values of HPMNPU were approximately 1269 mg g-1 and 1667 mg g-1 for CV and MV, respectively. This study showed that HPMNPU adsorbents exhibited high adsorption performance for the removal of CV and MV from water and could be promising adsorbent materials for the efficient removal of cationic dyes from wastewaters.

ZnS quantum dots impregnated-mesoporous TiO2 nanospheres for enhanced visible light induced photocatalytic application

ZnS quantum dots were impregnated on the surface of TiO₂ mesospheres by a soft template-assisted solvothermal approach.

Highly efficient visible-light photocatalytic activity of MoS2–TiO2 mixtures hybrid photocatalyst and functional properties

2D-layered molybdenum disulfide (MoS₂) and MoS₂/TiO₂ nanocomposite were synthesized by a hydrothermal method.