Enhanced Organic Pollutant Adsorption Using Zeolite-Carbon Dots Composites Synthesized by the Impregnation Method

Ho Tan Thanh; Nguyen Thien Phuc; Dang Dinh Khoi; Nguyen Quang Long

doi:10.22146/ijc.110466

Enhanced Organic Pollutant Adsorption Using Zeolite-Carbon Dots Composites Synthesized by the Impregnation Method

https://doi.org/10.22146/ijc.110466

Ho Tan Thanh⁽¹⁾, Nguyen Thien Phuc⁽²⁾, Dang Dinh Khoi⁽³⁾, Nguyen Quang Long^(4*)

(1) Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, Ho Chi Minh City 700000, Viet Nam; Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City 700000, Viet Nam; Ho Chi Minh City University of Industry and Trade, 140 Le Trong Tan Street, Tay Thanh Ward, Ho Chi Minh City 700000, Viet Nam;
(2) Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Viet Nam
(3) Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Viet Nam
(4) Faculty of Chemical Engineering, Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, Ho Chi Minh City 700000, Viet Nam; Vietnam National University Ho Chi Minh City, Linh Trung Ward, Ho Chi Minh City 700000, Viet Nam
(*) Corresponding Author

Abstract

In this study, a novel zeolite–carbon dots (ZCD) composite was synthesized via impregnation to enhance the adsorption performance of zeolite. The attachment of carbon dots (CDs) onto the zeolite surface was confirmed by SEM/EDS, TEM, BET, and FT-IR analyses. These results showed that CDs were uniformly dispersed on the FAU-type zeolite, introduced additional –OH, –CH_x, and –NH₂ groups, and increased the BET surface area from 444.5 to 491.5 m² g⁻¹. The presence of functional groups on the surface of CDs enhanced the adsorption capacity of zeolite. Notably, ZCD exhibited a 45% higher adsorption capacity for methylene blue (MB) than pristine zeolite, with a maximum experimental uptake of 32.53 mg g⁻¹. Adsorption isotherm and kinetic studies, best described by the Langmuir model (q_m = 29.22 mg g⁻¹, R² = 0.9815) and the pseudo-second-order kinetic model (R² = 0.9991), indicated that MB uptake on ZCD occurred through both physical and chemical interactions. These results suggest that the ZCD composite is a promising adsorbent for the removal of organic dyes in water treatment applications.

Keywords

zeolite composite; carbon dots; methylene blue; wastewater treatment; impregnation method

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DOI: https://doi.org/10.22146/ijc.110466