Interface engineering of metal organic framework on graphene oxide with enhanced adsorption capacity for organophosphorus pesticide

- A simple solvothermal method fabricated metal organic framework/grapheme oxide hybrid nanocomposite (UiO-67/GO).
- UiO-67/GO significantly enhanced the glyphosate adsorption capacity of GO.
- UiO-67/GO exhibited fantastic adsorption performance in a wide range of pH (2-8).

A simple solvothermal synthetic method was proposed for the fabrication of metal organic framework/grapheme oxide hybrid nanocomposite (UiO-67/GO), achieving dense and ordered UiO-67 on the surface of GO for the high-affinity capture of organophosphorus pesticides (OPPs). The composites were characterized by SEM, XRD, FTIR and TGA. The adsorption process and adsorption capacity of glyphosate was evaluated by kinetics and equilibrium adsorption isotherm study, respectively. The results indicate that the pseudo-second-order kinetic model and the Langmuir model correlated satisfactorily to the experimental data. The maximum adsorption capacity of glyphosate on UiO-67/GO is ∼2.855 mmol (482.69 mg) g−1 at pH 4, which catches up with and even surpasses that of most GO-based adsorbents. The excellent adsorption performances of UiO-67/GO toward OPPs are also presented in a wide range of pH 2-8. Moreover, the adsorption mechanism was further revealed using XPS and FTIR. Taking advantage of the abundant ZrOH groups on the surface of GO, as well as the large surface of available GO for enhancing the sequestration of target organophosphorus-pollutants, the as-prepared UiO-67/GO composites exhibit enhancement of adsorption capacity toward glyphosate. The experimental results suggest that the UiO-67/GO is a promising adsorbent for efficient removal of OPPs for the contaminated water purification.