Water stable graphene oxide metal-organic frameworks composite (ZIF-67@GO) for efficient removal of malachite green from water.

Malachite green (MG) is extensively applied in aquaculture worldwide as a therapeutic agent. MG and its primary metabolite leucomalachite green (LMG) are commonly detected in aquaculture products. MG can cause serious health concerns (in vivo carcinogenic/genotoxic). The extensive water solubility of MG leads to water pollution and hence it is mandatory to remove MG from water. The current study explores adsorptive removal of MG from water using highly water stable Zeolitic Imidazolate framework/graphene oxide composites (ZIF-67@GO). Adsorption performance of newly synthesized composites is justified for MG removal with excellent results of pseudo second order (R = 0.99955) which is well-fitted in this case. ZIF-67@GO data of adsorption isotherm for MG is observed using Freundlich Model (R = 0.99999) and with adsorption capacity value observed (134.79 mg/g) with removal efficiency of 99.18%, indicates π-staking and electrostatic association between ZIF-67@GO and MG molecules. Synthesized material has retained reusability while removal efficiency reduced only by 6% after many cycles. Furthermore, factors effecting absorption like contact time, pH, adsorbent dose and quantity and temperature are also determined.