A hydrogen sensor that efficiently detects hydrogen gas at room temperature comprising a gold decorated reduced graphene oxide/zinc oxide (Au/rGO/ZnO) heterostructured composite, methods for making this sensor and a method for sensitive room temperature detection of hydrogen using the sensor.

A hydrogen sensor that efficiently detects hydrogen gas at room temperature comprising a gold decorated reduced graphene oxide/zinc oxide (Au/rGO/ZnO) heterostructured composite, methods for making this sensor and a method for sensitive room temperature detection of hydrogen using the sensor.

A preparation method of a composite anode material of micrometer-sized carbon-coated silicon and carbon includes: subjecting micrometer-sized silicon particles to a chemical vapor deposition reaction under a gas atmosphere containing carbon to obtain carbon-coated first micrometer-sized silicon particles; dispersing the carbon-coated first micrometer-sized silicon particles in a first mixed solvent to obtain a dispersed solution; adding alkali into the dispersed solution and heating the dispersed solution to obtain carbon-coated second micrometer-sized silicon particles; dispersing the carbon-coated second micrometer-sized silicon particles and graphene oxide in a second mixed solvent that are subjected to a hydrothermal reaction to obtain a composite hydrogel of reduced graphene oxide, silicon, and carbon; and heating the hydrogel to obtain the composite anode material.

A secondary battery with favorable cycle performance is provided. Alternatively, a secondary battery with higher capacity is provided. A positive electrode active material layer including a first graphene layer, a second graphene layer, and a positive electrode active material. The first graphene layer includes a first region covering the positive electrode active material. The second graphene layer includes a second region covering the positive electrode active material and a third region overlapping with the first region. The first region includes a plane positioned between the positive electrode active material and the third region and formed of arranged six-membered carbon rings. The positive electrode active material includes a fourth region with a layered rock-salt structure. A lithium layer with a layered rock-salt structure included in the fourth region is substantially perpendicular to the plane formed of six-membered carbon rings and included in the second region.

The gel made of graphene oxide co-doped with boron nitrogen can be functionalized with a receptor, can be passivated by a passivation agent, and can have particular expressions of bonds to favor charge carrier mobility. The gel can be used in the context of a sensor via the interaction between the receptor and an analyte to be detected.

The gel made of graphene oxide co-doped with boron nitrogen can be functionalized with a receptor, can be passivated by a passivation agent, and can have particular expressions of bonds to favor charge carrier mobility. The gel can be used in the context of a sensor via the interaction between the receptor and an analyte to be detected.

A method of producing a graphene suspension, comprising: (a) mixing multiple particles of a graphitic material and multiple particles of a solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of the carrier material particles to produce graphene-coated carrier particles inside the impacting chamber; and (c) dispersing the graphene-coated carrier particles in a liquid medium and separating the graphene sheets from the carrier material particles using ultrasonication or mechanical shearing means and removing the carrier material from the liquid medium to produce the graphene suspension. The process is fast (1-4 hours as opposed to 5-120 hours of conventional processes), environmentally benign, cost effective, and highly scalable.

A method of producing a graphene suspension, comprising: (a) mixing multiple particles of a graphitic material and multiple particles of a solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; (b) operating the energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from the graphitic material and transferring the graphene sheets to surfaces of the carrier material particles to produce graphene-coated carrier particles inside the impacting chamber; and (c) dispersing the graphene-coated carrier particles in a liquid medium and separating the graphene sheets from the carrier material particles using ultrasonication or mechanical shearing means and removing the carrier material from the liquid medium to produce the graphene suspension. The process is fast (1-4 hours as opposed to 5-120 hours of conventional processes), environmentally benign, cost effective, and highly scalable.

Synthesizing Janus material including forming a lamellar phase having water layers and organic layers, incorporating nanosheets and a functional agent into the lamellar phase, and attaching the functional agent to the nanosheets in the lamellar phase to form Janus nanosheets.

Synthesizing Janus material including forming a lamellar phase having water layers and organic layers, incorporating nanosheets and a functional agent into the lamellar phase, and attaching the functional agent to the nanosheets in the lamellar phase to form Janus nanosheets.