Rutgers University engineers have found a simple method for producing high-quality graphene that can be used in next-generation electronic and energy devices: bake the compound in a microwave oven.
The discovery is documented in a study published online today in the journal Science.
"This is a major advance in the graphene field," said Manish Chhowalla, professor and associate chair in the Department of Materials Science and Engineering in Rutgers' School of Engineering. "This simple microwave treatment leads to exceptionally high quality graphene with properties approaching those in pristine graphene."
The discovery was made by post-doctoral associates and undergraduate students in the department, said Chhowalla, who is also the director of the Rutgers Institute for Advanced Materials, Devices and Nanotechnology. Having undergraduates as co-authors of a Science paper is rare but he said "the Rutgers Materials Science and Engineering Department and the School of Engineering at Rutgers cultivate a culture of curiosity driven research in students with fresh ideas who are not afraid to try something new.''
Graphene -- 100 times tougher than steel -- conducts electricity better than copper and rapidly dissipates heat, making it useful for many applications. Large-scale production of graphene is necessary for applications such as printable electronics, electrodes for batteries and catalysts for fuel cells.
Graphene comes from graphite, a carbon-based material used by generations of students and teachers in the form of pencils. Graphite consists of sheets or layers of graphene.
The easiest way to make large quantities of graphene is to exfoliate graphite into individual graphene sheets by using chemicals. The downside of this approach is that side reactions occur with oxygen -- forming graphene oxide that is electrically non-conducting, which makes it less useful for products.
Removing oxygen from graphene oxide to obtain high-quality graphene has been a major challenge over the past two decades for the scientific community working on graphene. Oxygen distorts the pristine atomic structure of graphene and degrades its properties.
Chhowalla and his group members found that baking the exfoliated graphene oxide for just one second in a 1,000-watt microwave oven, like those used in households across America, can eliminate virtually all of the oxygen from graphene oxide.
The Rutgers engineers' research was funded by the National Science Foundation, Rutgers Energy Institute, U.S. Department of Education and Rutgers Aresty Research Assistant Program.
Cite This Page:
Wataalamu wa Chuo Kikuu cha Rutgers wamegundua njia rahisi ya kutengeneza graphene ya hali ya juu ambayo inaweza kutumika katika vifaa vya umeme na nishati vya kizazi kijacho: kuchoma mchanganyiko katika tanuri ya microwave. Ugunduzi huo umethibitishwa katika utafiti uliochapishwa mtandaoni leo katika jarida la Sayansi. "Hii ni maendeleo makubwa katika uwanja wa graphene, ""alisema Manish Chouwalla, profesa na mwenyekiti msaidizi katika Idara ya Sayansi ya Vifaa na Uhandisi katika Shule ya Uhandisi ya Rutgers." "Utibuzi huu rahisi wa microwave husababisha graphene ya ubora wa juu sana yenye sifa zinazokaribia zile za graphene safi". Ugunduzi huo ulifanywa na washirika wa baada ya udaktari na wanafunzi wa shahada ya kwanza katika idara hiyo, alisema Chouwalla, ambaye pia ni mkurugenzi wa Taasisi ya Rutgers ya Vifaa vya Juu, Vifaa na Nanoteknolojia. "Kuwa na wanafunzi wa shahada ya kwanza kama waandishi wa karatasi ya Sayansi ni nadra lakini alisema ""Katiba ya Sayansi ya Vifaa na Uhandisi ya Rutgers na Shule ya Uhandisi ya Rutgers kukuza utamaduni wa utafiti unaoendeshwa na udadisi katika wanafunzi wenye mawazo mapya ambao hawaogopi kujaribu kitu kipya.""" Graphene ni ngumu mara 100 kuliko chuma, inaongoza umeme bora kuliko shaba na hupunguza joto haraka, na hivyo ni muhimu kwa matumizi mengi. Uzalishaji wa kiwango kikubwa cha graphene ni muhimu kwa matumizi kama vile elektroni inayoweza kuchapishwa, elektroni kwa betri na kichocheo kwa seli za mafuta. Graphene ni mchanganyiko wa graphite, ambayo ni nyenzo ya kaboni ambayo hutumiwa na wanafunzi na walimu kwa kizazi kimoja. Graphite ina karatasi au tabaka za graphene. Njia rahisi ya kutengeneza graphene kwa kiasi kikubwa ni kuondoa rangi ya graphite katika karatasi za graphene kwa kutumia kemikali. "Uchanganyiko wa ""mtazamo wa chini"" ni kwamba athari za upande hutokea na oksijeni - kuunda graphene oksidi ambayo ni umeme usioongoza, ambayo inafanya kuwa na manufaa kidogo kwa bidhaa." Kuondoa oksijeni kutoka kwa oksidi ya graphene ili kupata graphene ya ubora wa juu imekuwa changamoto kubwa katika miongo miwili iliyopita kwa jamii ya kisayansi inayofanya kazi kwenye graphene. Oksijeni hiharibu muundo safi wa atomu ya graphene na kuharibu sifa zake. Chouwalla na washiriki wa kikundi chake waligundua kuwa kuoka graphene oxide ya exfoliated kwa sekunde moja tu katika tanuri ya microwave ya 1,000-watt, kama zile zinazotumiwa katika nyumba kote Amerika, zinaweza kuondoa karibu oksijeni yote kutoka kwa graphene oxide. Utafiti wa wataalamu wa Rutgers ulifadhiliwa na Shirika la Sayansi la Kitaifa, Taasisi ya Nishati ya Rutgers, Idara ya Elimu ya Marekani na Programu ya Msaidizi wa Utafiti wa Aristide wa Rutgers. Namba hii ya ukurasa: