Enhanced adsorptive removal of Indigo carmine dye performance by functionalized carbon nanotubes based adsorbents from aqueous solution: equilibrium, kinetic, and DFT study

Abstract

The present work considers an adsorptive removal of Indigo carmine (IC) dye onto nanotube carbon (CNTs). The pure CNTs were prepared via chemical vapor deposition (CVD) method utilizing methane gas as a carbon source at 1000 °C in a quartz tube. The morphology and surface chemical structure of the adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption technique, and thermal gravity analysis (TGA). The parameters of the IC dye adsorption, such as initial concentration, contact time, pH, and mass-loaded adsorbent, were evaluated. The kinetic study confirmed that a pseudo-second-order model was best fitted to the adsorption data. The removal efficiency of adsorption onto pure and COOH-functionalized CNTs was 84% and 98.7% at 15 min, respectively. The equilibrium results were fitted well to the Langmuir isotherm model. The adsorption capacity of the CNT and COOH-CNT was 88.5 and 136 mg/g, respectively. The reusability of the adsorbents was studied, and after eight cycles, the efficiency decreased to 70%. Moreover, the density functional theory calculations confirmed that the functionalization of CNTs with COOH groups improves the adsorption properties of IC due to the formation of hydrogen-bonding interactions.

Enhanced adsorptive removal of indigo carmine dye by bismuth oxide doped MgO based adsorbents from aqueous solution: equilibrium, kinetic and computational studies

“…Batch removal studies were carried out in 50 mL screw-top bottles containing 25 mL IC dye solutions to elucidate the inuence of the operational parameters, including the pH solution (2)(3)(4)(5)(6)(7)(8)(9)(10)(11), initial IC dye concentration (10-100 ppm), and contact time (2-210 min). The mixture was stirred at 400 rpm for 3.0 h. Following each experiment, the mixture was centrifuged, and the residual concentrations of IC dye were determined using a LABOMED: UVS-2800 spectrophotometer at a maximum wavelength of 610 nm.…”

“…Photodegradation, electrocoagulation, electrochemical, occulation-coagulation, ultra-ltration, and adsorption are among the most used techniques. [11][12][13][14][15] Based on efficiency, scalability, low operation cost, simplicity, adsorption can be considered as the most preferred method for water treatment among all other techniques. The nature and amount of pollutants are the most essential factors for selecting the treatment method.…”

Recent advancements in transparent carbon nanotube films: chemistry and imminent challenges

“…One is the deep scattering of Gr and CNTs into a type of solvents, and therefore printable paints including high mass density corresponding to aggregate and a presumption would be formed. Owing to the unique chemical durability of CNTs, inherited TCF processing methods deepened at eroding compounds are unusually productive, and few innovative approaches are needed to complete floral CNT TCFs [122,123].…”

Hydrothermal Synthesis of Biomass-Derived Magnetic Carbon Composites for Adsorption and Catalysis

“…The affinity of the adsorbents for indigo carmine may be further enhanced by the presence of graphitic carbon on the hydrochar as revealed by XPS (Section ). Interaction between delocalized electrons in the indigo carmine and delocalized electrons in the adsorbate will facilitate adsorption via π-interactions . It should also be noted that, typically, the maximum adsorption capacity for indigo carmine is generally lower than methylene blue, e.g., a commercial activated carbon has exhibited a maximum adsorption capacity 7 times lower for indigo carmine (135 mg g –1 ) than for methylene blue …”