Graphene Oxide Functionalized by Ethylene Diamine Tetraacetic Acid (Edta) by a Hydrothermal Process as an Adsorbent for Nickel Ions

Abstract

"Graphene oxide (GO) from sugar cane bagasse (SCB/F) was treated with EDTA to produce modified GO (EGO) by a hydrothermal preparation reaction. Raman spectra showed an intensity ratio of ID/IG for SCB/F and EGO8:1 (EDTA:GO 8:1) of 0.598 and 0.391, respectively. FTIR spectra confirmed the introduction of nitrogen-containing groups into the SCB/F backbone. SEM analysis demonstrated the porosity character for the sample. The TGA/DTA results implied the EGO8:1 sample was less thermally stable than SCB/F. The Ni2+ adsorption study revealed a steadily increasing adsorption of Ni2+ until 45 min, with no noticeable increase in adsorption after that. The results of kinetic modeling, adsorption isotherms, and thermodynamic parameters showed that the pseudo-second-order models gave a better fit to the adsorption data of the SCB/F and EGO samples. Also, the adsorption data fitted the Langmuir model best, and the negative values of G indicated that the sorption process was spontaneous."

Eco-friendly Synthesis of Carbon Quantum Dots as an Effective Adsorbent

“…The bands centered at 1212–1457 and 1158–1358 cm −1 are usually attributed to C–O = C and C–O–C stretching Vibrations [ 15 – 17 ]. Functional groups resulting from urea, such as N–H and C–N, are centered at 3203–3359 and 1040–1150 cm −1 , respectively [ 12 ]. In addition, the FTIR spectrum revealed the presence of hydrophilic surface functional groups, such as OH and NH groups, over the CQDs surface, thus imparting excellent water solubility and stability [ 9 ].…”

“…K2 (g/mg/min) is the rate constant of Pseudo-second-order adsorption. Values of qe2 and K2 were calculated from the slope and intercept of the plot of t/qt against t, respectively [ 9 , 11 , 12 ].…”

“… where qm (mg/g) is the maximum removal capacity, Kf is the adsorption capacity. RT/b = B (J/mol) which is Temkin constants related to the heat of sorption, A (L/g) is the equilibrium binding constants corresponding to the maximum binding energy, R is the universal gas constant, and T (K) is the absolute temperature [ 9 , 12 ].…”

“…( 7 ), ( 8 ) and ( 9 ): where T is the temperature in Kelvin, R is the universal gas constant, and Kd is the distribution coefficient. ΔH and ΔS can be obtained from the slope and intercept of Van't Hoff plot of ln K versus 1/T, respectively [ 9 , 11 , 12 ].…”

Preparation of hydroxyethyl cellulose/ mangiferin edible films and their antimicrobial properties

“…where θ = Bragg’s angle in radians, λ = X-ray wavelength (0.1542 nm), and β & θ are full widths at half maxima and Bragg’s angle of the XRD peak, respectively [ 15 – 17 ].…”