Enhanced adsorption efficiency of inorganic chromium (VI) ions by using carbon-encapsulated hematite nanocubes

• Main Authors: Vu Thi Trang, Le Thi Tam, Nguyen Van Quy, Vu Ngoc Phan, Hoang Van Tuan, Tran Quang Huy, Ngo Xuan Dinh, Anh-Tuan Le
• Format: Article
• Language: English
• Published: Elsevier 2020-09-01
• Series: Journal of Science: Advanced Materials and Devices
• Subjects: Hematite nanocubes; Adsorption; Inorganic; Chromium removal; Adsorbent reuse
• Online Access: http://www.sciencedirect.com/science/article/pii/S2468217920300484

In this study, carbon-encapsulated hematite nanocubes with an edge length of ~20 nm (α-Fe2O3@C) were prepared by a two-step hydrothermal method using glucose as a carbon source. The α-Fe2O3@C nanocomposite was found to exhibit enhanced adsorption efficiency for inorganic chromium (VI) ions as compared to bare α-Fe2O3 nanocubes. At optimized conditions, the maximum adsorption capacity and removal efficiency of Cr(VI) using α-Fe2O3@C nanocomposites were 76.92 mg g−1 and 97.6%. The influence of carbon content on the structural features, and on the mechanism of adsorption of the α-Fe2O3@C nanocomposites were investigated and discussed. Adsorption data revealed that the adsorption behavior of the α-Fe2O3@C nanocomposites for chromium (VI) showed good agreement with both Langmuir and pseudo-second-order kinetic models. Moreover, the α-Fe2O3@C nanocomposites still retain high chromium (VI) removal efficiency after three recycles. Carbon-encapsulated hematite nanocubes with high Cr(VI) removal efficiency and excellent regenerability will become a promising absorbent toward the treatment of heavy metals from water solution.