Porous PVA/Zn–Fe–Mn oxide nanocomposites: methylene blue dye adsorption studies

Abstract

Adsorption is one of the noble techniques for remediation of organic and inorganic pollutants. The poly (vinyl alcohol) supported sol-gel and self-propagation routes have been used for the synthesis of porous ternary metal oxides nanocomposites. The optical, chemical bonding, crystallinity, morphological, textural, and electrochemical properties of the synthesized materials were characterized by DRS-UV-vis, FT-IR, XRD, SEM/EDX and TEM/HRTEM/SAED, BET, and CV/EIS techniques, respectively. The characterization of the nanocomposites confirmed their porous nature, high surface area, and better electrochemical properties. The synthesized nanomaterials were tested for the adsorption property of methylene blue dye. Important parameters such as the amount of PVA supported ternary metal oxide nanocomposite, pH of the solution, contact time, and concentration of methylene blue dye were optimized. For further understanding of the adsorption process, the adsorption isotherms and adsorption kinetics models were used. The adsorption tests revealed the presence of the chemisorption type of the adsorption process. several advantageous properties [8,9]. Besides, its hydroxyl groups on the carbon chain backbone act as a source for the formation of hydrogen bonding and enhances the formation of the nanocomposite [10]. As confirmed by various researchers [11][12][13][14][15][16], around 250, 300, 390, 400, and 400°C-500°C; the intramolecular decomposition, amorphous portion degradation, intermolecular breakdown, decaying of the crystalline portion of PVA, and formation of pure metal oxides had occurred, respectively.From methods used for the synthesis of inorganic nanomaterials/nanocomposites, the top-down and bottom-up approaches are common. Compared to the former, the latter is more popular and is considered as a promising route to control the growth, morphology, and properties of the nanomaterials. From the bottom-up chemical approaches; the hydrothermal, microemulsion, wet impregnation, sonochemical, ultrasonicmicrowave, electrochemical/electroless deposition, and spray-pyrolysis techniques are successfully applied. However, it is reported that these techniques follow special operating-conditions, long reaction time, lowthrough-put, and expensive procedure [17]. Therefore, it is essential to use effective and economically feasible methods such as sol-gel, precipitation, and impregnation. Furthermore, during the synthesis process, avoiding solvents that cause cancer and has mutagenic properties should also be taken into consideration [18].Considering all the mentioned aspects, this work was aimed to synthesize PVA supported ternary metal oxide nanocomposite (PVA-TMONC), using a simple and green sol-gel-self propagation technique. The methylene blue dye (MBD) adsorption efficiency of the synthesized PVA-TMONC was also tested. The physical properties of synthesized materials were characterized by critical analytical techniques. Using the Langmuir, Freundlich, Dubinin-Radushkevich (D-RK), Temkin, Flory-Huggins (FH), and Fowler-Gugge...

Multifunctional application of PVA-aided Zn–Fe–Mn coupled oxide nanocomposite

“…The instrumental details and the reagents used were present as supplementary material (S). The detailed ZnO and PTMO-NCM synthesis procedures were also present in the author's earlier works [1,[26][27][28]. Roughly, the PVA polymer was dissolved in distilled water with continuous stirring on a magnetic stirrer at ~ 115 °C for about 15 min.…”

“…The 20 ppm of 250 mL Congo red (CR) and Acid Orange-8 (AO8) dyes and 0.06 g of PTMO-NCM photocatalyst were used during the experiment. The adsorption test was conducted using the experimentally optimized [1] adsorption parameters, 10-150-min adsorbateadsorbent contact time, and 1-35 mg L −1 concentrations with a constant 140 rpm shaking speed. The antibacterial activity test had conducted using three different concentrations (75, 100, and 125 μg mL −1 ) of ZnO and PTMO-NCM.…”

“…The optimized 0.02 g dosage, pH of 8, and a constant 140 rpm shaking speed were used for the adsorption-reaction and adsorption-diffusion kinetics studies [1]. The coefficient of determination (R 2 ) value and equations used to calculate the adsorption kinetics models parameter was given in the respective plots as inset (Fig.…”

“…Zinc oxide nanoparticles (NPs) are commonly used in several fields such as adsorption [1], photocatalysis [2,3], food preservation [4], and pollutant sensor [5]. Compared to TiO 2 , the production cost of ZnO is approximately 75% lower and has higher absorption efficacy across a large fraction of the solar spectrum [6,7].…”

Synthesis and Characterization of PVA-Assisted Metal Oxide Nanomaterials: Surface Area, Porosity, and Electrochemical Property Improvement

“…The dried gel was grounded and calcined at 500°C for 3 hours. The detailed procedure is also reported on the author's earlier works [16,26] and shown in Figure S1. The same protocol was used for the synthesis of binary metal oxides by mixing two different metal salt precursors.…”