• • MIL-101-Bim achieved a theoretical maximum TC adsorption capacity of 86.31 mg·g−1, 2.18 times higher than MIL-101-CHO (39.56 mg·g−1), indicating enhanced adsorption efficacy for wastewater treatment applications.
• • The post-modification degree was quantified by 1H NMR: 41% benzimidazole grafting, 32% hydroxymethyl formation, and 27% unreacted formyl groups, providing precise control over functional group density.
• • The material retained a high specific surface area of 1361 m2·g−1 and pore sizes of 1–2.3 nm after modification, ensuring sufficient active sites for TC adsorption.
• • MIL-101-Bim exhibited good reusability, maintaining an adsorption capacity of 46.93 mg·g−1 after five adsorption-desorption cycles, which is critical for cost-effective industrial application.