Abstract: Provided are a method and system for preparing a two-dimensional material by means of a gas-phase method. The method comprises a gas-phase etching step: reacting gas having an etching effect with an MAX phase material at a first predetermined temperature, and etching a component A in the MAX phase material to obtain a two-dimensional material containing MX. The method avoids requiring the steps such as repeated cleaning, ultrasonic and centrifugal separation, and drying in preparing MXene in a liquid-phase method, greatly simplifies a preparation process, reduces the preparation cost, can achieve industrial macro preparation of MXene, and lays a foundation for application of MXene in different fields.

Abstract: Disclosed are a picture displaying method, an electronic device and a storage medium. The picture display method includes: receiving an event of triggering a movement of the picture, wherein the picture includes a plurality of picture elements displayed on a plurality of layers, respectively; acquiring at least one movement parameter corresponding to each of the plurality of layers based on the event, wherein at least one movement parameter corresponding to at least one of the plurality of layers differs from at least one movement parameter corresponding to any other layer among the plurality of layers; and generating the plurality of picture elements on the plurality of layers based on a plurality of movement parameters corresponding to the plurality of layers, respectively, in response to the event.

Abstract: In some embodiments, the present disclosure pertains to catalysts for mediating oxygen reduction reactions, such as the conversion of oxygen to at least one of H2O, H2O2, O2?, OH?, and combinations thereof. In some embodiments, the present disclosure pertains to methods of utilizing the catalysts to mediate oxygen reduction reactions. In some embodiments, the catalyst includes a carbon source and a dopant associated with the carbon source. In some embodiments, the catalyst has a three-dimensional structure, a density ranging from about 1 mg/cm3 to about 10 mg/cm3, and a surface area ranging from about 100 m2/g to about 1,000 m2/g. In some embodiments, the carbon source includes graphene nanoribbons, and the dopant includes boron-nitrogen heteroatoms. In some embodiments, the dopant is covalently associated with the edges of the carbon source. Additional embodiments of the present disclosure pertain to methods of making the aforementioned catalysts.

Abstract: Two-dimensional nanomaterials are produced in a process comprising the steps of (a) providing (a1) a mixture comprising graphene oxide particles, water and at least one cationic surfactant and/or nonionic surfactant or (a2) a mixture comprising graphene particles, at least one solvent useful for solution exfoliation of graphite and at least one cationic surfactant and/or nonionic surfactant, (b) adding at least one sol precursor compound to the mixture from step (a), (c) reacting the mixture from step (b) in a sol/gel process to form gel from the at least one sol precursor compound on the graphene oxide particles or, respectively, the graphene particles, (d) removing the at least one surfactant, and (e) optionally heating the gel-coated graphene oxide particles for at least 1 min to at least 500° C. under inert gas atmosphere to reduce the graphene oxide to graphene.

Abstract: In some embodiments, the present disclosure pertains to methods of making three-dimensional graphene compositions. In some embodiments, the methods comprise: (1) associating a graphene oxide with a metal source to form a mixture; and (2) reducing the mixture. In some embodiments, the method results in formation of a three-dimensional graphene composition that includes: (a) a reduced metal derived from the metal source; and (b) a graphene derived from the graphene oxide, where the graphene is associated with the reduced metal. In some embodiments, the metal source is (NH4)2MoS4, and the reduced metal is MoS2. In some embodiments, the metal source is V2O5, and the reduced metal is VO2. Further embodiments of the present disclosure pertain to the formed three-dimensional graphene compositions and their use as electrode materials in energy storage devices.

Abstract: The invention relates to a process for coating nanoparticles with graphene, comprising the steps of (a) providing a suspension comprising a suspension medium and nanoparticles with positive surface charge, (b) adding graphene oxide particles to the suspension from step (a), the graphene oxide particles accumulating on the nanoparticles, and (c) converting the graphene oxide particles accumulated on the nanoparticles to graphene, to graphene-coated nanoparticles comprising at least one metal, a semimetal, a metal compound and/or a semimetal compound, and to the use of these graphene-coated nanoparticles in electrochemical cells and supercapacitors, and to supercapacitors and electrochemical cells comprising these nanoparticles.

Abstract: The invention relates to a process for coating nanoparticles with graphene, comprising the steps of (a) providing a suspension comprising a suspension medium and nanoparticles with positive surface charge, (b) adding graphene oxide particles to the suspension from step (a), the graphene oxide particles accumulating on the nanoparticles, and (c) converting the graphene oxide particles accumulated on the nanoparticles to graphene, to graphene-coated nanoparticles comprising at least one metal, a semimetal, a metal compound and/or a semimetal compound, and to the use of these graphene-coated nanoparticles in electrochemical cells and supercapacitors, and to supercapacitors and electrochemical cells comprising these nanoparticles.

Abstract: Two-dimensional nanomaterials are produced in a process comprising the steps of (a) providing (a1) a mixture comprising graphene oxide particles, water and at least one cationic surfactant and/or nonionic surfactant or (a2) a mixture comprising graphene particles, at least one solvent useful for solution exfoliation of graphite and at least one cationic surfactant and/or nonionic surfactant, (b) adding at least one sol precursor compound to the mixture from step (a), (c) reacting the mixture from step (b) in a sol/gel process to form gel from the at least one sol precursor compound on the graphene oxide particles or, respectively, the graphene particles, (d) removing the at least one surfactant, and (e) optionally heating the gel-coated graphene oxide particles for at least 1 min to at least 500° C. under inert gas atmosphere to reduce the graphene oxide to graphene.