Defect-engineered MIL-100(Fe) via acid modulation for enhanced adsorption and selectivity in dye removal from wastewater


Hamzah M. A. A. M., Azmi M. A. M., Chia R. J. J., Yusof N., Lau W. J., Ismail A. F., ...More

Journal of Water Process Engineering, vol.91, 2026 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 91
  • Publication Date: 2026
  • Doi Number: 10.1016/j.jwpe.2026.110480
  • Journal Name: Journal of Water Process Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, INSPEC
  • Keywords: Acid modulation, Defect engineering, Dye removal, Dye selectivity, MIL-100(Fe), Porous materials
  • Ataturk University Affiliated: No

Abstract

Defect engineering in metal-organic frameworks (MOFs), particularly linker defects via acid modulation, has emerged as a promising strategy to enhance their performance in wastewater treatment. In this work, the defective MIL-100(Fe) was synthesized via modulation using four acid modulators – acetic acid, citric acid, benzoic acid, and gallic acid (GA) – to induce linker vacancies while tailoring its micro/mesoporous characteristics to rationalize these impacts on the dye adsorption efficiency. The introduction of defect sites led to significant changes, including reduced crystallinity, lower micro/mesopore volume ratio, and increased specific surface area. Notably, GA induced defective MIL-100(Fe), MIL-GA, exhibited a significantly large surface area (1060.56 m2/g) with a low micro/mesopore volume ratio (0.734) and higher unsaturated Fe defect density based on its high Fe/C ratio. Enhanced mesoporosity in the defective frameworks facilitates improved molecular diffusion and accessibility, leading to significantly improved adsorption capacity and selectivity. MIL-GA achieved a maximum adsorption capacity of 621.74 mg/g for reactive orange 16 (RO16) and demonstrated enhanced selectivity in binary dye systems (RO16/rhodamine B ratio = 2.59 and RO16/methylene blue ratio = 1.7). The adsorption behaviour followed the Elovich and Redlich-Peterson models, suggesting chemisorption and hybrid mono−/multilayer adsorption mechanisms. The nanomaterial retained over 80% adsorption efficiency after four regeneration cycles using dilute acidic ethanol, highlighting its reusability. These findings underscore the potential of defect-engineered MOFs as high-performance, selective, and recyclable adsorbents for practical dye removal from industrial wastewater.