Magnetization of TiO2 nanofibrous spheres by one-step ultrasonic-assisted electrochemical technique

Assessment of Performance of Photocatalytic Nanostructured Materials with Varied Morphology Based on Reaction Conditions

Synthesis of nanomaterials with specific morphology is an essential aspect for the optimisation of its properties and applications. The application of nanomaterials is being discussed in a wide range of areas, one of which is directly relevant to the environment through photocatalysis. To produce an effective photocatalyst for environmental applications, morphology plays an important role as it affects the surface area, interfaces, crystal facets and active sites, which ultimately affects efficiency. The method of synthesis and synthesis temperature can be the basic considerations for the evaluation of a particular nanomaterial. In this study, we have considered the aspects of morphology with a basic understanding and analyzed them in terms of nanomaterial efficacy in photocatalysis. Different morphologies of specific nanomaterials such as titanium dioxide, zinc oxide, silver phosphate, cadmium sulphide and zinc titanate have been discussed to come to reasonable conclusions. Morphologies such as nanorods, nanoflower, nanospindles, nanosheets, nanospheres and nanoparticles were compared within and outside the domain of given nanomaterials. The different synthesis strategies adopted for a specific morphology have been compared with the photocatalytic performance. It has been observed that nanomaterials with similar band gaps show different performances, which can be linked with the reaction conditions and their nanomorphology as well. Materials with similar morphological structures show different photocatalytic performances. TiO₂ nanorods appear to have the best features of efficient photocatalyst, while the nanoflowers show very low efficiency. For CdS, the nanoflower is the best morphology for photocatalysis. It appears that high surface area is the key apart from the morphology, which controls the efficiency. The overall understanding by analyzing all the available information has enumerated a path to select an effective photocatalyst amongst the several nanomaterials available. Such an analysis and comparison is unique and has provided a handle to select the effective morphology of nanomaterials for photocatalytic applications.

Modeling and optimization of Photocatalytic Decolorization of binary dye solution using graphite electrode modified with Graphene oxide and TiO2

In this paper, the experimental design methodology was employed for modeling and optimizing the operational parameters of the photocatalytic degradation of a binary dye solution using a fixed photocatalytic compound. The compound used was modified graphite electrode (GE) with graphene oxide (GO) on which TiO₂ nanoparticles were immobilized. GO nanoparticle was deposited on graphite electrode (GO-GE) using electrochemical approach. TiO₂ nanoparticles were immobilized on GO-GE by solvent evaporation method. A binary solution containing mixture of methylene blue (MB) and acid red 14 (AR14) was chosen as dye model. The degradation intermediates were detected and analyzed using gas chromatography. Effect of different factors on the photocatalytic decolorization efficiency was investigated and optimized using response surface methodology (RSM). The obtained results indicated that the prepared TiO₂-GO-CE can decolorize MB with high efficiency (93.43%) at pH 11, dye concentration of 10 mg/L and 0.04 g of immobilized TiO₂ on the GO fabricated plates after 120 min of photocatalytic process. It was demonstrated that by modifying GE with GO the stability of the electrode was remarkably enhanced. The ANOVA results (R² = 0.97 and P value <0.0001 for MB, R² = 0.96 and P value <0.0001 for AR14) and numerical optimization showed that it is possible to make good prediction on decoloration behavior and save time and energy with less number of experiments using design of experiments (DoE) like the RSM. Graphical abstract Wastewater treatment processWastewater treatment process.