Synthesis of Gd0.5Sr0.5FeO3 perovskite-type nanopowders for adsorptive removal of MB dye from water

Abstract

In the present study, nanoparticles of perovskite-type Gd 0.5 Sr 0.5 FeO 3 (GSFO) were fabricated by a sol-gel method. A series of analytical techniques were used to characterize the crystallinity, morphology, specific surface area and grain size of GSFO powders. The thermal decomposition process of the complex precursor was examined by means of differential thermal analysis-thermal gravimetric analysis. X-ray diffraction results showed that a single perovskite phase was completely formed after calcination at 700°C. In addition, transmission electron microscopy images revealed that the average size of the particles is approximately 35.23 nm in diameter. The surface morphology and composition of these nanopowders were also investigated using a scanning electron microscope and an energy dispersive X-ray spectrometer. GSFO nanoparticles showed excellent adsorption efficiency towards methylene blue dye in aqueous solution. The adsorption studies were carried out at different pH values, initial dye concentrations, various adsorbent doses and contact time in batch experiments. The dye removal efficiency was found to be increased with increasing the initial pH of the dye solution, and GSFO exhibited good dye removal efficiency at a basic pH, especially at a pH of 12. Experimental results indicated that the adsorption kinetic data follow a pseudo-second-order rate for the tested dye. The isotherm evaluations revealed that the Redlich-Peterson model attained better fits to the experiment's equilibrium data than the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models.

Wastewater Purification from Permanganate Ions by Sorption on the Ocimum basilicum Leaves Powder Modified by Zinc Chloride

“…In spite of the impressive effectiveness of activated carbon, the cost of preparing is very high. Other materials like metallic oxides nanoparticles (NPS) have been used as sorbents for purification wastewater from different dyes [17][18][19][20][21][22][23]. On the other hand, many researchers have used cheap and available materials in their areas as sorbents to get rid of water-pollution dyes.…”

Development of LaMnO3 and LaNiO3 type materials with calcium doping by the modified proteic method and evaluation for the dye removal efficiency

“…The most noticeable differences were between the no doping and partial doping materials, whose efficiencies were 82% and 92% for LM9-C and L5C5M9-C, respectively, and 87% and 94% for LN9-C and L5C5N9-C, respectively. It was noted that Ca 2+ ion insertion in the material significantly improved adsorbent activity, indicating that by partially replacing site A ions with other lower valence cations, such as the substitution of La 3+ with Ca 2+ , oxygen vacancies are formed, which can contribute to the adsorption ions and move across the surface of the material, promoting interaction between species [14,19,24]. The material L5C5N9-C was the best adsorbent even without the smallest crystallite, but it was the material that presented the largest surface area and this fact can be explained by the imbalance of nickel charges in Ni 2+ and Ni 3+ when partially replaced by Ca 2+ .…”

“…Because it is a relatively simple technique, the use of adsorption for the removal of pollutants is constantly increasing, for example in the removal of dyes [5,[24][25][26][27][28].…”

Synthesis and characterization of nanocomposite NiFe2O4@SalenSi and its application in efficient removal of Ni(II) from aqueous solution

“…The constant represents the capacity of the adsorbent for the adsorbate and n is related to the adsorption adsorbate values for the Freundlich model (R 2 = 0.999) are closer to unity than those for the other isotherm models (Langmuir: R 2 = 0.958 and Temkin: R 2 = 0.955) for adsorption process onto NiFe 2 O 4 @SalenSi. This indicates that the adsorption of Ni(II) on NiFe 2 O 4 @SalenSi particles is better described by the Freundlich model than the Langmuir and Temkin models and generally it has been found better suited for characterizing monolayer adsorption process onto the homogenous adsorbent surface (Figure 10 (a, b, c)) [34]. …”