Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water (original) (raw)
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Polymer brushes on graphene oxide for efficient adsorption of heavy metal ions from water
Journal of Applied Polymer Science, 2019
The pollution of heavy metal ions in water poses a serious threat to human being and ecosystems. Here, we report polyamidoxime (PAO) brush grafted graphene oxide (GO) as a highly efficient adsorbent for extraction of toxic metal cations from water. Surface-initiated atom transfer radical polymerization was used to grow polyacrylonitrile (PAN) brushes on GO, followed by conversion of the nitrile groups in PAN into amidoxime groups, which had high binding affinity toward heavy metal cations. The PAO brush grafted GO demonstrated significantly fast adsorption kinetics and large adsorption capacity. At optimal pH 5, the PAO brush grafted GO can achieve maximum adsorption capacities of 116.7 mg g −1 for Pb(II), 258.6 mg g −1 for Ag(I), 192.2 mg g −1 for Cu(II), and 167.9 mg g −1 for Fe(III), which were significantly larger than those of small molecule functionalized GO. Mechanism analysis suggested that the enhanced adsorption performance was due to the myriads of functional groups in PAO brushes that were easily accessible to metal ions because of the swelling of the polymer brushes in water.
Recent Advances in Applications of Hybrid Graphene Materials for Metals Removal from Wastewater
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The presence of traces of heavy metals in wastewater causes adverse health effects on humans and the ecosystem. Adsorption is a low cost and eco-friendly method for the removal of low concentrations of heavy metals from wastewater streams. Over the past several years, graphene-based materials have been researched as exceptional adsorbents. In this review, the applications of graphene oxide (GO), reduce graphene oxide (rGO), and graphene-based nanocomposites (GNCs) for the removal of various metals are analyzed. Firstly, the common synthesis routes for GO, rGO, and GNCs are discussed. Secondly, the available literature on the adsorption of heavy metals including arsenic, lead, cadmium, nickel, mercury, chromium and copper using graphene-based materials are reviewed and analyzed. The adsorption isotherms, kinetics, capacity, and removal efficiency for each metal on different graphene materials, as well as the effects of the synthesis method and the adsorption process conditions on the...
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This manuscript deals with the preparation of graphen oxide À metal oxide composite for the removal of heavy metal ions from water by adsoprtion. Composite of graphene oxide (GO) with zink oxide and titanium oxide has been prepared and analyzed structurally. Further, these composites has been used for the removal of heavy metals such as lead, chromium, mercury etc. from water. Metal oxide GO composites has been found efficient towards removal of heavy metal ions.
Nano Revolution: Pioneering the Future of Water Reclamation with Micro/Nanorobots
Nanoscale advances, 2024
Earth's freshwater reserves are alarmingly limited, with less than 1% readily available. Factors such as industrialisation, population expansion, and climate change are compounding the scarcity of clean water. In this context, self-driven, programmable micro-and nano-scale synthetic robots offer a potential solution for enhancing water monitoring and remediation. With the aid of these innovative robots, diffusion-limited reactions can be overcome, allowing for active engagement with target pollutants, such as heavy metals, dyes, nano-and micro-plastics, oils, pathogenic microorganisms, and persistent organic pollutants. Herein, we introduced and reviewed recent influential and advanced studies on micro-/nanorobots (MNR) carried out over the past decade. Typical works are categorized by propulsion modes, analyzing their advantages and drawbacks in detail and looking at specific applications. Moreover, this review provides a concise overview of the contemporary advancements and applications of micro-/ nano-robots in water-cleaning applications.
Improved removal of lead (ii) from water using a polymer-based graphene oxide nanocomposite
Journal of Materials Chemistry A, 2013
Poly(N-vinylcarbazole) (PVK) was blended with graphene oxide (GO) to form a PVK-GO polymer nanocomposite capable of adsorbing heavy metal from aqueous solutions. The homogenous distribution of GO in the PVK-GO nanocomposite was determined by X-ray photoelectron microscopy (XPS) and attenuated total reflectanceinfrared spectroscopy (ATR-IR). The results show that the adsorption capacity of Pb 2+ by the nanocomposite increased with increasing amount of GO. This phenomenon was attributed to the increasing concentration of oxygen-containing functional groups available in the nanocomposite. Furthermore, the adsorption of Pb 2+ onto PVK-GO nanocomposite was influenced by pH changes. Higher pHs had a better adsorption capacity than lower pHs, due to changes in the nanocomposite surface properties. The highest adsorption capacity of the PVK-GO nanocomposite for Pb 2+ was 887.98 mg g À1 and fits well the Langmuir model. This adsorption capacity was achieved using a 10 : 90 wt% ratio of PVK : GO at pH 7 AE 0.5 with a 90 min contact time. The high removal efficiency of this nanocomposite suggests that PVK-GO is effective and can be applied to remove heavy metals from water.
Removal of Lead Ions From Aqueous Solutions Using Melamine-Modified Nano Graphene Oxide
2021
Today, due to the industrialization of societies, the existence of heavy metals has created many problems for humans, other organisms, and the environment. Lead (Pb) is highly toxic and the second most commonly used metal. The aim of this study was to evaluate the efficiency of melaminemodified nanographene oxide in the removal of Pb from aqueous media. To increase the efficiency of graphene oxide, it was mechanically converted to nano graphene oxide and melamine (4, 2 and 6-triazine, 3, 1 and 5 triamine). Experiments were performed at pH value of 3-8, temperature of 15-50°C, Pb concentration of 5-200 mg/g, adsorbent dose of 0.01-0.06 g, and contact time of 15150 minutes. The mechanism of the adsorption process was investigated using two Langmuir and Freundlich isotherm models, pseudo-first order and pseudo-second order kinetic equations, and thermodynamic equations. The results showed that the adsorption rate corresponds to the Freundlich isotherm model and pseudo-second order kine...
Adsorption of heavy metals from aqueous media on graphene-based nanomaterials
AIP Conference Proceedings, 2018
The present paper considers experimental studies carried out to determine the effective kinetic parameters of the adsorption of heavy metal ions (Cu 2+ , Zn 2+ , and Cr 3+) from aqueous solutions using graphene oxide (GO) and the composite materials on the basis thereof-polyamine cumulene/graphene (PAC/G) and polyquinone/graphene (PQ/G)-under static and ambient temperature conditions. The following results were obtained: GO-adsorption time 20 min (for all the metal ions), and adsorption capacity 60, 26, and 5.5 mg g −1 (for Cu 2+ , Zn 2+ +, and Cr 3+ , respectively); PAC/G: adsorption time 30 min, adsorption capacity 26 mg g −1 (for Cu 2+); and PQ/G: adsorption time 30 min, adsorption capacity-40 mg g −1 (for Cu 2+). According to the experimental data, more than 90 % of the adsorption capacity was achieved in the first 20 min of the contact between the GO and the heavy metal solutions. The equilibrium of the system was reached at the same time, regardless of the extracted component and the degree of adsorption. The PAC/G and PQ/G also exhibited high adsorption capacity values for the heavy metal ions in comparison with the conventional materials. Thus, the graphene-based nanomaterials can be successfully used for removing the heavy metal ions from aqueous media, which is very important from an environmental point of view (e.g., water treatment purposes).
Critical Reviews in Environmental Science and Technology, 2017
Graphene-based materials have been extensively employed for removal of heavy metals and radionuclides from water and wastewater. This work critically reviews the current status of researches on the use of graphene as well as its modified materials, and their efficacy for the adsorption of heavy metals and radionuclides. It focuses on the examination of different factors influencing the adsorption capacity, including the properties of graphene-based materials, solution pH, contact time, initial concentration of metal ions, initial dosage of graphene-based
Polydopamine-mediated surface-functionalization of graphene oxide for heavy metal ions removal
Journal of Solid State Chemistry, 2015
By utilizing polydopamine (PD) nano-thick interlayer as mediator, polyethylenimine (PEI) brushes with abundant amine groups were grafted onto the surface of graphene oxide (GO) uniformly via a Michael-Addition reaction and produced a PEI-PD/GO composite nanosheets. The PEI-PD/GO composite exhibited an improved performance for adsorption of heavy metal ions as compared to PEI-coated GO and pure GO. The adsorption capacities for Cu 2+ , Cd 2+ , Pb 2+ , Hg 2+ are up to 87, 106, 197, and 110 mg/g, respectively. To further make the GO based composite operable, PEI-PD/RGO aerogel was prepared through hydrothermal and achieved a high surface area up to 373 m 2 /g. Although the adsorption capacity of PEI-PD/RGO aerogel for heavy metal ions decreases a little as compared to PEI-PD/GO composite dispersion (38, 32, 95, 113 mg/g corresponding to Cu 2+ , Cd 2+ , Pb 2+ , and Hg 2+ , respectively), it could be recycled several times in a simple way by releasing adsorbed metal ions, indicating its potential application for cleaning wastewater.