▎ 摘　　要

NOVELTY - Producing graphene nanosheets, comprises e.g.: injecting a carbon-containing substance into a thermal zone of a plasma at a velocity of at least 60 m/second standard temperature and pressure (STP) to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of not greater than 1000 degrees C, where the graphene nanosheets have a polyaromatic hydrocarbon concentration of less than 0.7 wt.%; and injecting the carbon-containing substance into the thermal zone of plasma at the velocity of at least 60 m/second STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with the quench gas of not greater than 1000 degrees C, to produce the graphene nanosheets with a Raman G/D ratio of greater than or equal to 3 and a 2D/G ratio of greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm. USE - The process: is useful for producing graphene nanosheets; allows to produce high quality graphene nanosheets at high throughput by dispersing and quenching the hydrocarbon gas adequately; and allows economical and large-scale production. ADVANTAGE - The process provides graphene nanosheets with a low specific surface area of greater than or equal to 250 m2/g as measured by ASTM D 3663-78 (claimed). DETAILED DESCRIPTION - Producing graphene nanosheets, comprises: injecting a carbon-containing substance into a thermal zone of a plasma at a velocity of at least 60 m/second standard temperature and pressure (STP) to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas of not greater than 1000 degrees C, where the graphene nanosheets have a polyaromatic hydrocarbon concentration of less than 0.7 wt.%; injecting the carbon-containing substance into the thermal zone of plasma at the velocity of at least 60 m/second STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with the quench gas of not greater than 1000 degrees C, to produce the graphene nanosheets with a Raman G/D ratio of greater than or equal to 3 and a 2D/G ratio of greater than or equal to 0.8, as measured using an incident laser wavelength of 514 nm; injecting the carbon-containing substance into the thermal zone of plasma at a velocity of at least 60 m/second STP and at a quench gas to carbon ratio of at least 75 standard liter per minute (slpm) of quench gas per mole of carbon injected per minute, to produce the graphene nanosheets; injecting the carbon-containing substance into the thermal zone of plasma at velocity of at least 60 m/second STP and at a quench gas to supplied plasma torch power ratio of at least 1.25 slpm of quench gas per kW of supplied plasma torch power, to produce the graphene nanosheets; injecting the carbon-containing substance into the thermal zone of plasma, where the injecting of the carbon-containing substance is carried out using many jets at velocity of at least 60 m/second STP and directed so that the injected carbon-containing substance is distributed radially about a torch axis and diluted before reaching a quench gas, to produce the graphene nanosheets with a Raman G/D ratio of greater than or equal to 3 and a 2D/G ratio of greater than or equal to 0.8 as measured using an incident laser wavelength of 514 nm; injecting the carbon-containing substance into the thermal zone of plasma at velocity of at least 60 m/second STP and at a quench gas to supplied plasma torch power ratio of at least 1.25 slpm of quench gas per kW of supplied plasma torch power, to produce the graphene nanosheets at a rate of at least 120 g/hour; injecting the carbon-containing substance into the thermal zone of plasma, where the injecting of the carbon-containing substance is carried out using many jets at velocity of at least 60 m/second STP and directed so that the injected carbon-containing substance is distributed radially about a torch axis and diluted before reaching a quench gas, to produce the graphene nanosheets at a rate of at least 120 g/hour; injecting the carbon-containing substance into the thermal zone of plasma at velocity of at least 60 m/second, to produce the graphene nanosheets at a rate of at least 2 g/kWh of supplied plasma torch power; injecting the carbon-containing substance into the thermal zone of plasma at velocity of at least 60 m/second and with a supplied plasma torch power greater than 35 kW, to produce the graphene nanosheets at a rate of at least 80 g/hour; or injecting natural gas or methane into the thermal zone of plasma at a velocity of at least 60 m/second STP to nucleate the graphene nanosheets, and quenching the graphene nanosheets with a quench gas.