مقاله انگلیسی رایگان در مورد سنتز گرافن بر اساس نانومواد برای حذف فلزات سنگین – الزویر 2018

The advanced synthesis and development of raw graphene based on various significant functionalization has been outstanding in the wastewater treatment compared to the other alternatives such as carbon nanotubes and other carbon nanomaterials. Nano size graphene is known to possess large surface area and some promising properties in terms of mechanical, electrical, chemical and magnetism. Besides, the graphene can be generated via both Top-down and Bottom-up methods such as chemical exfoliation, chemical vapor deposition and other techniques so that it can be further functionalized to form graphene oxide-based nanomaterials. Hence, graphene oxide-based nanomaterials are discovered to be useful in the application of heavy metal removal from wastewater. In short, this paper critically reviewed on the synthesis method of graphene and application of graphene oxidebased nanomaterials in the term of heavy metal removal. The advantages, drawbacks, comparison of the data efficiencies, and research requirements are further highlighted, elaborated and discussed detailly. Lastly, the future challenges of graphene are elaborated. Therefore, it can be guaranteed that the wastewater discharged should be detected with the minimum or none of the heavy metals so that minimum effects on the ecosystem is discovered.

Introduction

Graphene can be extracted from graphite and it is merely a sheet of graphite. It is defined as a single layer of sp2 bonded carbon atoms in hexagonal lattice arrangement. At the same time, graphene possesses few promising properties such as good electronic properties caused by the bonding and anti-bonding of the pi orbitals. Furthermore, graphene is clarified to be the strongest substance in terms of mechanical strength since it possesses high tensile strength and it is light in weight. For instance, it is more than 40 times stronger than diamond and more than 300 times stronger than A36 structural steel, at 130 GPa[1]. Meanwhile, for the optical properties, high absorption of white light up to 2.3% is capable to be observed from graphene. Besides of the impressive properties, appropriate method to produce graphene must be taken into consideration. There are two different type of methods to produce graphene which are exfoliation methods and direct growth of graphene layer which can be known as Top-down and Bottom-up methods respectively[2]. Methods to generate graphene include “Scotch Tape Method”, dispersion of graphite, exfoliation of graphite oxide, epitaxial growth and lastly chemical vapor deposition (CVD)[3]. However, improved Hummers method which falls under method of dispersion of graphite is widely used since it is an improved method which excludes the usage of toxic chemical and at the same time enhances the reaction performance[4].

چکیده

توسعه و سنتز پیشرفته ی گرافن خام بر اساس عملکردهای مختلف و قابل توجه در زمینه ی تصفيه فاضلاب، در مقایسه با سایر راهکارهاي جايگزين (مانند نانولوله هاي كربني و ساير نانو مواد كربني)،بسيار چشمگير بوده است. گرافن در ابعاد نانو داراي مساحت سطح بزرگ و برخي ويژگي هاي نويد بخش از نظر مكانيكي، شيميايي،الكتريكي و مغناطيسي است.علاوه بر اين گرافن مي تواند از هر دو روش پايين به بالا و بالا به پايين ،مانند لايه برداري شيميايي،رسوب دهی شیمیایی بخار و روش های دیگر تولید شود بنابراین ، بنابراین نانو‌مواد بر پایه ی اکسید گرافن برای حذف فلزات سنگین از فاضلاب مفید در نظر گرفته شده اند . به طور خلاصه این مقاله مروری است بر روی روش های سنتز گرافن وکاربرد نانو مواد برپایه ی اکسید گرافن د رحذف فلزات سنگین. در این مقاله فواید،نقص ها و مقایسه ی بازده ی داده ها و تحقیقات مورد نیاز، بیشتر برجسته شده و با جزییات توضیح داده شده و مورد بحث قرارگرفته است. در آخر چالش های آینده ی گرافن مورد بررسی قرار گرفته است. بنابراین می توان تضمین کرد که تخلیه ی فاضلاب باید با حداقل مقدار فلز سنگین یا بدون آن در نظر گرفته شود تا کمترین اثر را روی اکو سیستم بگذارد.