Construction of a TiO₂–Fe₃O₄‐decorated molecularly imprinted polymer nanocomposite for tartrazine degradation: Response surface methodology modeling and optimization

Abstract

We synthesized a novel recoverable and reusable photocatalyst system for tartrazine degradation by one-step incorporation of Fe 3 O 4 and TiO 2 nanoparticles into a molecularly imprinted polymer through a facile precipitation polymerization method. The as-prepared samples were systematically characterized using X-ray diffraction, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, and vibrating sample magnetometry. Benefiting from the positive synergistic effect, tartrazine was almost completely degraded under UV-C within 180 min by the multicomponent photocatalyst (Fe 3 O 4 + TiO 2 + MIP) in comparison with far fewer activities by the corresponding NIP system and the nonmagnetic and bare structures. On the other hand, the central composite design in response surface methodology was applied to optimize the tartrazine photocatalytic degradation process. Twenty experiments were conducted by adjusting three parameters (nanocomposite dosage, initial pH of the reaction solution, and initial dye concentration) in the multiple variable analysis method. A satisfactory correlation between the experimental and predicted values was obtained (R 2 = 0.956). Additionally, ANOVA analysis with a p value of 1.15 × 10 -5 indicated that the model terms are highly significant. Under the determined optimum conditions, a verification experiment was conducted and shown the adequately approximate value between the predicted (99%) and the experimental (97%) results, which confirmed the validity of the model. K E Y W O R D S molecularly imprinted polymer, nanocomposite, response surface methodology, tartrazine

Effect of phosphomolybdic acid on the catalytic behavior of bifunctional Pt‐Cr/nanocrystalline Y zeolite in hydroisomerization of n‐octane

“…As mentioned above, the isomerization reactions proceed through carbenium ion intermediates formed on strong acid sites, and the acidity of the catalysts seems to be a determining factor in explaining the difference in catalytic activity, especially toward the isomerization reaction between these catalysts . Therefore, the presence of the Brønsted acidity of catalysts was determined using the back titration method . The values obtained were 0.75, 1.21, and 1.19 mmol H + g −1 for Pt/Y, Pt/HPMo‐Y, and Cr.Pt/HPMo‐Y, respectively.…”

“…Y zeolite‐supported HPMo was prepared using the impregnation technique . An appropriate amount of HPMo (10 wt%) was dissolved in 50 mL of DI water and added dropwise to a nanocrystalline Y zeolite suspension in water.…”

“…The Brønsted acidity of catalysts was determined by using the back titration method . The catalyst (0.1 g) was suspended in 20 mL NaOH (0.01 N) for 48 hr, and after that, it was separated by centrifuge.…”

“…Thus, in the third stage of this work, to evaluate the efficiency of the hydroisomerization reaction, the response surface methodology (RSM), based on the Box–Behnken design (BBD), has been applied to specify the effect of the variables studied (weight hourly space velocity [WHSV], the H 2 to n‐C 8 molar ratio, and the reaction temperature on the yield of the synthesized iso‐alkanes. BBD was used due to its superiority over the traditional OFAT approach . The advantages of BBD can be summarized as a reduction in the number of experimental runs and, consequently, low experimental costs, the ability to evaluate the interactive effects of the operational variables, and the possibility of optimizing the operational variables, to achieve the maximum yield of iso‐alkane.…”

“…BBD was used due to its superiority over the traditional OFAT approach. [27] The advantages of BBD can be summarized as a reduction in the number of experimental runs and, consequently, low experimental costs, the ability to evaluate the interactive effects of the operational variables, and the possibility of optimizing the operational variables, to achieve the maximum yield of isoalkane. In this respect, a three-level BBD method was used to model and optimize the hydroisomerization reaction.…”