Novel carbazole-based porous organic frameworks (CzBPOF) for efficient removal of toxic Pb(II) from water: Synthesis, characterization, and adsorption studies

Herein, a novel carbazole-based porous organic framework CzBPOF was synthesized successfully via aldol triple condensation reaction and was used to remove toxic Pb(II) from aqueous media. The synthesized CzBPOF was characterized by FTIR, TGA, BET, SEM, EDX, EMA 13C CP/MAS NMR and XPS analysis The Brunauer–Emmett–Teller (BET) specific surface area of CzBPOF was found to be 615 m2 g−1. The influence of different parameters on adsorption of Pb(II) on CzBPOF was investigated and the outcomes revealed that the optimal contact time, pH, initial Pb(II) concentration, and temperature were found to be 80 min, 5, 200 mg/L, and 30 °C, respectively. The adsorption process followed Langmuir isotherm and PSO kinetic models, indicating that the adsorption process belongs to monolayer adsorption and chemisorption. The CzBPOF adsorbent had a maximum monolayer capacity of 318.4 mg/g at 30 °C. The thermodynamic results confirmed that Pb(II) adsorption using CzBPOF was endothermic, spontaneous, and the adsorption process follows a physicochemical mechanism. The FTIR, XPS, and EDX analysis confirm the adsorption of Pb(II) ions using CzBPOF adsorbent. The CzBPOF adsorbent shows excellent reusability with a removal efficiency of 84.26% after three cycles. In summary, the as-prepared CzBPOF adsorbent is effective and provides a promising prospect for the elimination of Pb(II) from an aqueous media. [Display omitted] •A novel carbazole-based porous organic framework CzBPOF was synthesized.•The BET surface area of CzBPOF adsorbent was found to be 615 m2/g.•CzBPOF showed excellent adsorption capacity for Pb(II) with 318.4 mg/g.•Adsorption of Pb(II) ions using CzBPOF was spontaneous and endothermic in nature.