Efficient removal of Rhodamine-B dye using sulfonated/un-sulfonated three-dimensional mesoporous carbon nitride prepared from KIT-6 template: kinetics, modelling, thermodynamic analysis


Gokcan M., Koyuncu D. D., OKUR M.

RESEARCH ON CHEMICAL INTERMEDIATES, vol.50, no.9, pp.4125-4153, 2024 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 50 Issue: 9
  • Publication Date: 2024
  • Doi Number: 10.1007/s11164-024-05366-7
  • Journal Name: RESEARCH ON CHEMICAL INTERMEDIATES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, Environment Index
  • Page Numbers: pp.4125-4153
  • Keywords: Dye adsorption, Kinetics, KIT-6, Mesoporous carbon nitride, Rhodamine-B, Sulfonation
  • Gazi University Affiliated: Yes

Abstract

Mesoporous carbon nitride (MCN-K) was prepared using mesoporous KIT-6 material as a template and ethylenediamine and carbon tetrachloride as N and C sources, respectively. The synthesized MCN-K was treated with sulfuric acid under different experimental conditions, thus obtaining sulfonated MCN-KS adsorbents. The effects of initial solution pH, initial dye concentration, adsorbent amount, and temperature on Rhodamine-B (Rh-B) dye removal were investigated. The XRD, FT-IR, and N2 adsorption-desorption analyses confirmed that the mesoporous carbon nitride structure was successfully synthesized. The high nitrogen content (C/N molar ratio: 4.0) of the MCN-K sample was confirmed by (carbon, hydrogen, nitrogen and sulfur) CHNS elemental analysis. The XPS analysis was used to characterize the chemical states of the C, N and S atoms in the MCN-K and MCN-KS sorbents. It was found that there was not much difference between the removal percentages (93.13-89.92%) obtained in the pH range (4-12) studied. This result was attributed to the zwitter-ion form of Rh-B. The exothermic nature of the adsorption process of Rh-B on the MCN-K sorbent was determined by adsorption experiments performed at different temperatures. Adsorption capacities obtained from the Langmuir model were 185.2-104.2 mg/g in the studied temperature range. The kinetic behavior of the adsorption process was explained by the pseudo-second-order kinetic model in terms of both correlation coefficients (R-2 > 0.91) and q(e) (35.59-190.26 mg/g) values. When the percentages of dye removal of the un-sulfonated and sulfonated samples were compared, it was found that sulfonation increased the adsorption rate considerably but did not contribute positively to the dye removal percentage.