Manganese-Oxide-Modified Porous Carbon from Ulva prolifera for Efficient Cd(II) Removal: Adsorption Behavior and Mechanisms
- 1Haikou Key Laboratory of Marine Contaminants Monitoring Innovation and Application, Haikou Marine Geological Survey, China Geological Survey, Haikou 571127, China
Abstract
Biochar materials exhibit promising prospects in adsorption–separation owing to their large specific surface area and well-developed pore structures. Herein, a series of manganese-oxide-modified porous carbon adsorbents (PEC-MnOx) were fabricated via the pyrolysis method, using Ulva prolifera as the carbon source and KMnO4 as the activator. XRD, SEM, TEM, N2 adsorption–desorption, FT-IR and XPS were employed to characterize the morphology, crystal phase, pore structure and surface chemical properties of the as-prepared materials. The results demonstrated that KMnO4 activation effectively optimized pore architecture, increased specific surface area, and generated abundant unsaturated –Mn–OH sites and oxygen vacancies. Batch adsorption experiments were carried out to evaluate Cd(II) removal performance. PEC-MnOx-6 displayed the optimal adsorption capability with an equilibrium adsorption uptake of 152.4 mg/g at 298.15 K. Kinetic fitting suggested that the pseudo-first-order model better described the adsorption behavior. Intraparticle diffusion analysis confirmed the multi-step mass-transfer nature, and liquid-film diffusion acted as the primary rate-limiting step. Both Langmuir and Freundlich isotherm equations obtained high correlation coefficients, indicating the coexistence of homogeneous active sites and heterogeneous pores/defects on the carbon matrix. Combined with characterization results, Cd(II) sequestration was realized through synergistic effects mainly including surface complexation and ion exchange, with the assistance of electrostatic interaction. This work provides a reference for high-value utilization of Ulva prolifera biomass and remediation of Cd(II)-contaminated wastewater.
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BibTeX
@article{zhang2026manganeseoxidemodified,
title = {{Manganese-Oxide-Modified Porous Carbon from Ulva prolifera for Efficient Cd(II) Removal: Adsorption Behavior and Mechanisms}},
author = {Yuhang Zhang and Baoli Wang and Xiujiu Yang},
journal = {Molecules},
year = {2026},
month = oct,
doi = {10.3390/molecules31193509},
url = {https://www.mdpi.com/1420-3049/31/19/3509},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Manganese-Oxide-Modified Porous Carbon from Ulva prolifera for Efficient Cd(II) Removal: Adsorption Behavior and Mechanisms
AU - Yuhang Zhang
AU - Baoli Wang
AU - Xiujiu Yang
PY - 2026
DA - 2026/10/01
JO - Molecules
DO - 10.3390/molecules31193509
UR - https://www.mdpi.com/1420-3049/31/19/3509
AB - Biochar materials exhibit promising prospects in adsorption–separation owing to their large specific surface area and well-developed pore structures. Herein, a series of manganese-oxide-modified porous carbon adsorbents (PEC-MnOx) were fabricated via the pyrolysis method, using Ulva prolifera as the carbon source and KMnO4 as the activator. XRD, SEM, TEM, N2 adsorption–desorption, FT-IR and XPS were employed to characterize the morphology, crystal phase, pore structure and surface chemical properties of the as-prepared materials. The results demonstrated that KMnO4 activation effectively optimized pore architecture, increased specific surface area, and generated abundant unsaturated –Mn–OH sites and oxygen vacancies. Batch adsorption experiments were carried out to evaluate Cd(II) removal performance. PEC-MnOx-6 displayed the optimal adsorption capability with an equilibrium adsorption uptake of 152.4 mg/g at 298.15 K. Kinetic fitting suggested that the pseudo-first-order model better described the adsorption behavior. Intraparticle diffusion analysis confirmed the multi-step mass-transfer nature, and liquid-film diffusion acted as the primary rate-limiting step. Both Langmuir and Freundlich isotherm equations obtained high correlation coefficients, indicating the coexistence of homogeneous active sites and heterogeneous pores/defects on the carbon matrix. Combined with characterization results, Cd(II) sequestration was realized through synergistic effects mainly including surface complexation and ion exchange, with the assistance of electrostatic interaction. This work provides a reference for high-value utilization of Ulva prolifera biomass and remediation of Cd(II)-contaminated wastewater.
SN - 1420-3049
ER -