Porous La2O2CO3 derived from solvent-guided metal-organic frameworks for high-efficient phosphorus removal

La-based materials have garnered considerable attention as potential adsorbents for phosphate removal because they capture phosphate with high affinity, producing an ultralow phosphorous-concentration output. Herein, La-based metal–organic frameworks (La–MOFs, La-1,3,5-benzentricarboxylate) with tunable structures were fabricated by regulating the coordination solvent environment, which largely determines both the pore structure and chemical components of their corresponding La 2 O 2 CO 3 derivatives and the phosphate adsorption performance. A porous La 2 O 2 CO 3 derivative (W–D T500) derived from the water/N,N-dimethylformamide (DMF) guided La–MOF showed abundant mesopores and a high surface area, because the pore-opening degree under high-temperature pyrolysis is higher in W–D T500 than in the La 2 O 2 CO 3 derivative obtained from the water/ethanol solvent–guided La–MOF. W–D T500 also had higher La (78.3%) and carbonate contents of the crystal structure owing to the higher efficiency of carbon conversion to carbonate-oxides in W–D T500. Consequently, the porous La 2 O 2 CO 3 derivative W–D T500 exhibited superior phosphate adsorption capacity (91.6 mg P/g), high adsorption selectivity, and excellent recycling performance. Phosphate was attached to the La 2 O 2 CO 3 adsorbents via a ligand-exchange mechanism between phosphate and CO 3 2− /–OH. This study provides a solvent guidance strategy to construct functional La–MOFs and La 2 O 2 CO 3 derivatives for excellent phosphate removal.