Efficient adsorption and photocatalytic degradation of methylene blue using HKUST-1: A novel approach for dye removal and wastewater treatment under sunlight

In this study, a three-dimensional HKUST-1 metal-organic framework (MOF) was synthesized via a solvothermal method under optimized conditions (110 °C for 4 h), achieving high crystallinity and a yield of 75 %. The material was characterized using XRD, FESEM, FTIR, TG, and BET analysis, revealing a surface area of 534.7 m²/g, and the dual performance of HKUST-1 as both an adsorbent and a photocatalyst was investigated using Methylene Blue (MB) as a model pollutant. The material demonstrated an adsorption efficiency of 95.04 ± 1.00 % and a sunlight-driven photodegradation efficiency of 86 %, with a photodegradation rate constant of 0.019 ± 0.360 min⁻¹ , the radical scavenging experiments confirmed that superoxide radicals (•O₂⁻) were the dominant active species. Furthermore, the material retained over 80 % of its removal efficiency after four reuse cycles. These findings demonstrate that HKUST-1 is a promising bifunctional material for sustainable wastewater dye treatment under natural sunlight. • Synthesized highly crystalline HKUST-1 MOF with 75 % yield and a BET surface area of 534.65 m²/g. • Demonstrated 96 % adsorption efficiency and 86 % photocatalytic degradation of Methylene Blue under sunlight. • Identified ⋅O₂⁻ radicals as dominant active species, with a high photodegradation rate constant of 0.019 min⁻¹. • HKUST-1 maintained crystallinity, structural integrity, and > 80 % efficiency after four adsorption-photodegradation cycles. • Proved HKUST-1 as a durable, regenerable, and dual-functional material for sustainable wastewater dye remediation.