Simple and efficient removal of Pb(II) ion from aqueous solution through adsorption has accelerated the development of many new composites to improve this popular method. In this study, the composites of graphene oxide (GO), zeolitic imidazolate framework-8 (ZIF-8), and magnetic materials were synthesized via coprecipitation method utilizing a different molar ratio between FeCl2 and FeCl3 of 1:0.5, 2:1, 3:1.5, and 4:2. The ZIF-8/GO was prepared via room temperature synthesis method prior to its further modification with magnetic materials for ease of separation. It was observed that the MZIF-8/GO2 of molar ratio 2:1 showed the best performance in adsorbing Pb(II) ion. As confirmed by FESEM image, it appeared to be ZIF-8 particles that have grown all over the GO platform and overlayed with Fe3O4 granular-shaped particles. The MZIF-8/GO2 successfully achieved 99% removal of Pb(II) within 10 min. The optimum values obtained for the initial concentration of Pb (II) were 100 mg/L, pH of 4 to 6, and adsorbent dosage used was 10 mg. The Langmuir isotherm and the pseudo-second-order kinetic model were deemed suitable to evaluate the adsorption of Pb(II) using MZIF-8/GO2. Results showed that MZIF-8GO2 achieved a maximum adsorption capacity of 625 mg/g of Pb(II) adsorption. All parent materials demonstrated a good synergistic effects, while exhibiting a significant contribution in providing active sites for Pb(II) adsorption. Therefore, this ternary composite of MZIF-8/GO2 is expected to be a promising adsorbent for Pb(II) adsorption from aqueous solution with an added value of ease of post phase separation using external magnetic field.
The recently emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become a significant and topmost global health challenge of today. SARS-CoV-2 can propagate through several direct or indirect means resulting in its exponential spread in short times. Consequently, finding new research based real-world and feasible solutions to interrupt the spread of pathogenic microorganisms is indispensable. It has been established that this virus can survive on a variety of available surfaces ranging from a few hours to a few days, which has increased the risk of COVID-19 spread to large populations. Currently, available surface disinfectant chemicals provide only a temporary solution and are not recommended to be used in the long run due to their toxicity and irritation. Apart from the urgent development of vaccine and antiviral drugs, there is also a need to design and develop surface disinfectant antiviral coatings for long-term applications even for new variants. The unique physicochemical properties of graphene-based nanomaterials (GBNs) have been widely investigated for antimicrobial applications. However, the research work for their use in antimicrobial surface coatings is minimal. This perspective enlightens the scope of using GBNs as antimicrobial/antiviral surface coatings to reduce the spread of transmittable microorganisms, precisely, SARS-CoV-2. This study attempts to demonstrate the synergistic effect of GBNs and metallic nanoparticles (MNPs), for their potential antiviral applications in the development of surface disinfectant coatings. Some proposed mechanisms for the antiviral activity of the graphene family against SARS-CoV-2 has also been explained. It is anticipated that this study will potentially lead to new insights and future trends to develop a framework for further investigation on this research area of pivotal importance to minimize the transmission of current and any future viral outbreaks.