Magnetron sputtering-coated tungsten biochar: efficient adsorption of Cu (II) and methylene blue from wastewater

Biochar has gained attention for its sustainability and versatility, particularly in developing efficient materials for environmental remediation. Modifying biochar with metal sites alters its chemical surface, enhancing its ability to adsorb contaminants. Tungsten-coated biochar samples were prepared using the innovative magnetron sputtering technique, varying power from 100 to 200 W and deposition time from 10 to 40 min. Various characterization techniques confirmed these samples’ surface modifications and adsorptive potential for copper Cu(II) and methylene blue (MB). The power and deposition time influenced the tungsten coating percentage on the biochar, the adsorbent’s features, and its adsorption potential. Higher power and longer deposition times increased the tungsten percentage on the biochar surface but reduced the material’s adsorption potential. The best adsorption results were achieved with the BW2 sample (150 W power and 20 min). Kinetic studies indicated that the pseudo-first-order and pseudo-second-order models fit well with the Cu (II) and MB adsorption curves, respectively. The Freundlich isotherm model best described the adsorption process, confirming the heteroge neous nature of the adsorbent surface. The adsorption of MB was more efficient at pH 6 (96 %) and pH 8 (94 %), decreasing in a basic medium (pH 10) due to electrostatic repulsion. For Cu (II), the best result was observed at pH 6 (48 %), associated with lower competition with H+ and greater stability of hydroxylated species. The controlled deposition of tungsten on the biochar surface via magnetron sputtering is a promising approach to enhancing its adsorption potential. The maximum adsorption capacities were 37.5 mg g− 1 for Cu (II) and 45.0 mg g− 1 for MB

• Autores: Benvegnú, Isadora A.; Silva, Luis; AlMasoud, Najla; Alomar, Taghrid S.; Crissien, Tito; da Silva, Thamires R.; Aguzzoli, Cesar; Godinho, Marcelo; Dotto, Guilherme L.
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2025
• Institución: Corporación Universidad de la Costa
• Repositorio: REDICUC - Repositorio CUC
• Idioma: eng
• OAI Identifier: oai:repositorio.cuc.edu.co:11323/14172
• Acceso en línea: https://hdl.handle.net/11323/14172; https://repositorio.cuc.edu.co/
• Palabra clave: Biochar; Dye adsorption; Metal adsorption; Deposition; Power
• Rights: openAccess
• License: Atribución 4.0 Internacional (CC BY 4.0)