Synthesis of a poly(p-aminophenol)/starch/graphene oxide ternary nanocomposite for removal of methylene blue dye from aqueous solution

Abstract

In the current study, poly(p-aminophenol) (PpAP), with starch and graphene oxide (GO), were successfully synthesised by oxidative polymerisation from p-aminophenol monomer in an aqueous alkaline medium using ammonium persulfate (APS) as an oxidising agent. The synthesised polymers were characterised using UV-Vis spectroscopy, Fourier transform infrared, thermogravimetric analysis, X-ray diffraction (XRD), and Brunauer-Emmett-Teller and zeta potential techniques. These techniques confirmed the presence of site-selective interaction between the conjugated PpAP chain and π-bonded surface, and thus the H-bonding of starch and GO. Further, the enhanced dye removal efficiency was ascribed to the improved morphology and the pore volume created by the entangled PpAP/Starch/GO. The influences of experimental conditions such as the polymer composite content, dye concentration, time, pH of the bath solution, and temperature on cationic dye adsorption were investigated. The adsorption data were fixed to the Langmuir isotherm (R 2 in the range between 0.997 and 0.9995) and showed a pseudo-second order (R 2 = in the range between 0.996 and 0.9996) kinetic model. Moreover, the polymer ternary composite was able to remove a large proportion (96.7%) of the cationic dye from water at pH 7. The thermodynamic investigation found that the adsorption process was spontaneous and endothermic. In addition, the synthesised adsorbent showed good reusability at six cycles. The data acquired suggest that the PpAP/Starch/GO composite can be effectively applied and reused as an inexpensive adsorbent material for removal of MB dye from water.

Effective Removal of Nile Blue Dye from Wastewater using Silver-Decorated Reduced Graphene Oxide

“…It also emphasizes adsorption on the somewhat heterogeneous surface of the adsorbent. This model operates on two major assumptions: (i) it provides details regarding the adsorbate/adsorbent interactions and the enthalpy of adsorption, asserting that the heat of adsorption rises as the surface is covered and (ii) it posits adsorption as a uniform dispersion of binding sites with uniform energies up to a certain limit . The linear form of its typical equation is as follows: q e = B 0.25em ln 0.25em K TM + B 0.25em ln 0.25em C e where K Tm and B represents the Temkin’s adsorption constants, with K Tm corresponds to the maximum binding energy (mg/L), and B refers to the heat of adsorption.…”

Effect of Graphene Oxide and Temperature on Electrochemical Polymerization of Pyrrole and Its Stability Performance in a Novel Eutectic Solvent (Choline Chloride–Phenol) for Supercapacitor Applications

“…A detailed process for preparing GO was presented in our previous work. 41 The proposed structure and the details are shown in Figure S1 .…”

“…GO was synthesized from graphite powder according to a modified Hummers method. A detailed process for preparing GO was presented in our previous work . The proposed structure and the details are shown in Figure S1.…”

Chitosan/Silica Nanocomposite Preparation from Shrimp Shell and Its Adsorption Performance for Methylene Blue

“…At the same t ple does not need to adjust the pH value and can achieve the best methylene tion effect. When the pH of the solution is low, the dimethyl amino group in ylene blue is easy to protonate, and H + in the solution will form a competiti relationship with methylene blue [34]. In addition, when the pH < pHZPC, a…”

“…At the same time, this sample does not need to adjust the pH value and can achieve the best methylene blue adsorption effect. When the pH of the solution is low, the dimethyl amino group in the dye methylene blue is easy to protonate, and H + in the solution will form a competitive adsorption relationship with methylene blue [34]. In addition, when the pH < pH ZPC , a large amount of H + will protonate the surface of the adsorbent and form electrostatic repulsion with methylene blue, resulting in reduced adsorption capacity of methylene blue.…”