The textile industry produces dye pollutants that are both harmful and difficult to degrade. This study explores the enhanced adsorption of Malachite Green (MG) dye using coconut carbon shells treated with RF glow oxygen plasma discharge. Plasma treatment improved the surface properties of the adsorbent by introducing oxygen-containing functional groups and increasing surface polarity, which boosted dye adsorption through hydrogen bonding, electrostatic interactions, and π-π stacking. Experimental results revealed that a 10-minute plasma treatment optimally enhanced adsorption capacity by 39 % compared to untreated samples. The Langmuir isotherm model demonstrated a maximum adsorption capacity (qm) of 161 mg/g, surpassing the Freundlich model. At pH 8, using 0.2 g of adsorbent in 50 mL solutions with initial dye concentrations of 25 mg/L and 100 mg/L, the 10-minute plasma-treated samples achieved adsorption capacities of 6.01 mg/g and 23.95 mg/g, respectively, compared to 4.72 mg/g and 17.2 mg/g for the untreated samples. This corresponded to removal efficiencies of 96.12 % and 95.8 % for the treated samples, and 75.6 % and 68.8 % for the untreated samples, after 80 min of contact at 200 rpm. UV–vis spectrophotometry confirmed the reduction in dye concentration after adsorption. FE-SEM analysis revealed that plasma treatment created micro-pores on the coconut carbon shell, enhancing adsorption capacity, while SEM-EDX analysis showed increased oxygen content after 10 min of treatment. FTIR analysis identified additional carbonyl (-C=O) and hydroxyl (-OH) groups, indicating the incorporation of oxygen-containing functional groups due to plasma treatment. Confocal Raman microscopy was also used to analyze the microstructural changes in the samples.