Water pollution is one of the most serious environmental challenges the world faces nowadays. Adsorption has emerged as a promising method for addressing this issue. In this study, novel adsorbents were synthesized by combining zeolitic imidazolate framework-8 (ZIF-8) and zeolitic imidazolate framework-67 (ZIF-67) with layered triple hydroxide (LTH)/calcined layered triple hydroxide (cLTH) through various synthesis approaches. These adsorbents were thoroughly characterized using a range of techniques to determine their textural properties, crystallinity, and functional groups before being applied to treat wastewater samples contaminated with a variety of pollutants, including acid red 1 (AR1), methyl orange (MO), crystal violet (CV), methylene blue (MB), 2-nitrophenol (2NP), bisphenol A (BPA), lead (Pb(II)), and chromium (Cr(VI)). Rather than assuming that hybridization would generally enhance adsorption performance, this work adopts a systematic comparative screening approach to evaluate pristine ZIFs, LTH/cLTH, and their nanocomposites across a broad pollutant matrix, revealing selective, pollutant-dependent enhancement and establishing a performance map that identifies best-in-class adsorbent–pollutant pairings. For instance, the adsorption capacities of CV onto cLTH, ZIF-8, and cLTH@ZIF-8 nanocomposite were found to be 286.3, 406.8, and 1335.3 mg/g, respectively, demonstrating the superiority of the nanocomposite. Additionally, the LTH@ZIF-67 nanocomposite showed superior CV adsorption performance (1027.9 mg/g) relative to pristine LTH (318.0 mg/g) and ZIF-67 (892.3 mg/g). Zeta potential measurements and the textural properties of the synthesized materials suggest that the adsorption of the aforementioned pollutants onto the synthesized adsorbents (including the nanocomposites) is likely governed by multiple mechanisms. Overall, the findings reported herein reveal the potential of the novel adsorbents synthesized in this study in boosting water decontamination.
Bahadi et al. (Mon,) studied this question.