• 专利标题:   Forming graphene-based product e.g. single graphene sheet involves heating mixture comprising graphite-based precursors and reduction-expansion agent e.g. urea in inert atmosphere to produce reducing gas and form graphene-based product.
  • 专利号:   US8894886-B1
  • 发明人:   LUHRS C C, PHILLIPS J
  • 专利权人:   STC.UNM
  • 国际专利分类:   C01B031/04
  • 专利详细信息:   US8894886-B1 25 Nov 2014 C01B-031/04 201478 Pages: 6 English
  • 申请详细信息:   US8894886-B1 US040976 04 Mar 2011
  • 优先权号:   US339502P, US040976

▎ 摘  要

NOVELTY - Forming a graphene-based product comprises forming a solid phase, physical mixture comprising one or more graphite-based precursors and one or more solid phase reduction-expansion chemical agents consisting of urea or thiourea, and heating the physical mixture in an inert atmosphere at a temperature sufficient to thermally decompose the solid phase reduction-expansion chemical agent to produce a reducing gas and form a graphene-based product, where each of the graphite-based precursors comprises one or more of a graphite oxide, and/or an expandable graphite. USE - The method is useful for forming a graphene-based product including a single graphene sheet, a stack of single graphene sheets and entangled single graphene sheets and forming free-standing graphene, where the graphene-based product comprises a nanosheet (all claimed) and is useful as an electrode of a supercapacitor, a battery, a fuel cell and a solar cell. ADVANTAGE - The method is capable of simply, rapidly and economically forming the graphene-based product using simple equipment with high quality and yield, low oxygen contents, controlled amounts of nitrogen and/or other impurities and improved thermal conductivity, strength, stiffness and electrical properties. The graphene-based product has high surface area and high volume-to-weight ratio. DETAILED DESCRIPTION - Forming a graphene-based product comprises: either (a) forming a solid phase, physical mixture comprising one or more graphite-based precursors and one or more solid phase reduction-expansion chemical agents consisting of urea or thiourea, and (b) heating the physical mixture in an inert atmosphere at a temperature sufficient to thermally decompose the solid phase reduction-expansion chemical agent to produce a reducing gas and form a graphene-based product, where each of the graphite-based precursors comprises one or more of a graphite oxide, and/or an expandable graphite; or (a1) forming a physical mixture by physically mixing graphite oxide with a reductive-expansion agent comprising urea, (b1) heating the physical mixture in an inert atmosphere at a heating temperature to form a free-standing graphene-based product, where the heating temperature is at or above a decomposition temperature of the reductive-expansion agent, and (c1) cooling the free-standing graphene-based product. An INDEPENDENT CLAIM is included for forming a free-standing graphene comprising the step (a1) as above per se, heating the physical mixture to form free-standing graphene, and cooling the free-standing graphene, where the free-standing graphene comprises graphene sheets.