ABSTRACT Biomass-derived palm carbon (PC) obtained from oil palm empty fruit bunches was synthesized via a facile synthesis approach through integration with Metal–Organic Frameworks (MOFs) of Cu(II)- and Fe(III)-benzene-1,4-dicarboxylate (BDC) to fabricate hybrid carbon/MOFs composites, denoted as PC–CB-1 and PC–FB-1. X-Ray Diffraction revealed a transformation from amorphous carbon to crystalline composite phases with triclinic symmetry for PC–CB-1 and monoclinic symmetry for PC–FB-1, indicating metal-dependent structural evolution and lattice reorganization. SEM–EDX analysis confirmed pore restructuring and homogeneous dispersion of Cu and Fe active centres within the carbon matrix, generating distinct surface heterogeneity and coordination environments. These structural differences directly governed adsorption behaviour toward dissolved ammonia, where PC–FB-1 achieved the highest adsorption capacity (≈0.23 mg g -1 ) and rapid equilibrium attainment within 60 min, whereas PC–CB-1 exhibited heterogeneous adsorption associated with defect-rich domains. Isotherm modelling indicated Langmuir-type monolayer adsorption for PC–FB-1 and Freundlich-type multilayer adsorption for PC–CB-1, while kinetic data showed excellent agreement with the pseudo-2 nd -order model, confirming chemisorption-controlled mechanisms through electrostatic interactions and Lewis acid–base coordination at metal sites. The findings demonstrate that controlled modulation of crystallographic symmetry and metal-site dispersion in biomass-derived carbon/MOFs composites enables rational tuning of adsorption kinetics and surface reactivity, providing insight into structure–property relationships in sustainable porous materials.
Zubir et al. (Mon,) studied this question.