adma201302435-普通棉花变身碳纤维溶胶 一种新型的高效可再生石油及有机溶剂吸附剂

普通棉花变身碳纤维溶胶 一种新型的高效可再生石油及有机溶剂吸附剂

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arbon Fiber Aerogel Made from Raw Cotton: A Novel, CEf cient and Recyclable Sorbent for Oils and Organic Solvents Hengchang Bi ,Zongyou Yin ,Xiehong Cao ,Xiao Xie ,Chaoliang Tan ,Xiao Huang ,Bo Chen , Fangtao Chen , Qingling Yang , Xinyang Bu , Xuehong Lu , Litao Sun ,* and Hua Zhang *

In order to solve the environmental and ecological problems in

the earth arising from the increasing pollution from the crude oil, petroleum products and toxic organic solvents, it is urgent

[1–4]to develop an economic and feasible strategy. Although

many conventional methods such as combustion, the use of oil

[2booms or oil skimmer vessels, ] and sorbents such as expanded

[5[7perlite, ] zeolites [6 ] and activated carbon, ] have been devel-oped to solve the aforementioned problems, they either show poor ef ciency or may introduce other types of contamination

[2,5–11]during the cleanup procedure.

C arbon-based three-dimensional (3D) networks with out-standing properties, such as low density, high electrical con-ductivity, high porosity, large speci c surface area and chemical inertness, have been extensively investigated and shown much potential in catalyst supports, supercapacitors, gas sensors and

[12–15so on. ] In particular, their low density, high porosity and hydrophobic properties make them attractive candidates for the removal of pollutants and the separation of oil and water. Gen-erally, there are three types of carbon-based 3D frameworks,

[16,17including organic aerogels pyrolyzed in an inert atmosphere, ]

sponges of carbon nanotubes (CNTs) or their derivatives fabri-[18,19cated by chemical vapor deposition (CVD), ] and graphene-[4,20,21]based aerogels from self-gelation. However, the organic

aerogels are fragile and dense in weight, and thus are not effec-[16,17tive in oil absorption. ] In addition, the preparation of CNT-based sponges needs expensive precursors and complex equip-ment that hamper their massive production for practical applica-[18,19]tions. Graphene-based aerogels could be used for sorption

H. C. Bi,[+] Dr. X. Xie, F. T. Chen, Q. L. Yang,

X. Y. Bu, Prof. L. T. SunSEU-FEI Nano-Pico Center

Key Laboratory of MEMS of Ministry of Education Southeast University Nanjing ,210096 ,P. R. China Tel: 86-025–83792632–8813, Fax: 86–025–83792939E-mail: slt@seu.edu.cn

[+][+]

H. C. Bi, Dr. Z. Y. Yin, Dr. X. H. Cao, C. L. Tan, Dr. X. Huang, B. Chen, Prof. X. H. Lu, Prof. H. Zhang

School of Materials Science and Engineering Nanyang Technological University

Singapore ,639798 ,50 Nanyang Avenue ,Singapore Tel: 65–67905175, Fax: 65–67909081

Website: doc.guandang.net: HZhang@ntu.edu.sg [+] These authors contributed equally to this work.

DOI: 1

0.1002/adma.201302435 5916

of various oils and organic solvents that was demonstrated by

[4]our group, presenting a high sorption capacity and outstanding

recyclability. However, the use of large amount of chemicals and generation of acidic waste during the preparation of GO seri-ously restrict their industrialization, which pushes us to explore a facile, economical and environmentally friendly strategy to massive production of carbon-based aerogels.

Due to their low cost, rich source, nontoxicity to humans,

etc., materials from the nature are receiving increasing atten-[12,22,23]tion. Cellulose is one of the most abundant, sustainable and environmentally friendly materials in nature. Recently, the production of carbon nano ber aerogels from bacterial cellu-lose, an arti cially synthetic cellulose, has been achieved and the resultant materials presented good performance in sorp-[12tion of oils and organic solvents. ] However, the production

process is complicated and expensive, thus restricting their industrial applications. Raw cotton, a typical natural material,

[24,25is cheap and sustainable and contains 90–95% cellulose, ]

making it a promising raw material for fabrication of carbon-based aerogels. Although raw cotton bers have been used for

[26,27][28][29,30sorption of dyes, heavy metals and heavy oil, ] their

poor buoyancy characteristics, low oil-sorption capacity, unsat-isfactory hydrophobicity and recyclability, etc. hamper their application in removal and separation of pollutants from water. Herein, lightweight, hydrophobic and porous aerogels made from twisted carbon bers (TCF) are produced via a facile route by using cotton bers as raw materials. Importantly, the TCF aerogel can absorb a wide range of organic solvents and oils with a maximum sorption capacity up to 192 times the weight of the pristine TCF aerogel. Moreover, the TCF aerogel also exhibits the excellent recyclability, and maintains a high sorp-tion capacity even after ve cycles through distillation, burning or squeezing. We believe that such natural cotton-derived novel carbon aerogel with good performance will have great potential for industrial applications and environmental protection. A few pieces of puri ed raw cotton with cylindrical shape (see the experimental section for details) were pyrolyzed at 800 °C for 2 h at a low pressure ( ～ 0.5 mbar) under argon atmosphere to generate black and lightweight TCF aerogels. After pyrolysis, the diameter of the cylindrical cotton decreased from 3 cm to 1.5 cm (insets in Figure 1aand 1b, respectively) and the height decreased from 1.5 cm to 0.9 cm. The volume of the TCF aerogel is thus only ～ 15% of that of the raw cotton.

3measured The TCF aerogel has a low density of ～ 12 mg cm

by Archimedes’ principle. Scanning electron microscopy (SEM)

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Adv. Mater. 2013, 25, 5916–5921