Facial fabrication of few-layer functionalized graphene with sole functional group through Diels-Alder reaction by ball milling

The widespread use of graphene as a next-generation material in various applications requires developing an environmentally friendly and efficient method for fabricating functionalized graphene. Chemically, graphene can be used as an electron donor or attractor. Here, graphite was successfully exfoliated, and an in situ Diels–Alder reaction (D–A) was carried out to fabricate functionalized graphene with sole functional groups via mechanochemical ball milling. The reactivities of graphene acting as a diene or a dienophile were investigated. Few-layer (≤2 layers) graphene specimens were obtained by wet ball milling, heating in a nitrogen atmosphere, and solvent ultrasonic treatment. The ball-milling method was more effective than heating in a nitrogen atmosphere, and the [2 + 4] D–A of graphene was more dominant than the [4 + 2] D–A in the ball-milling process. The surface tension of functionalized graphene decreased, which provided a theoretical basis for the dispersion and exfoliation of graphite in a suitable solvent. Functionalized graphene still had a high electrical conductivity, which has far-reaching significance for functionalized graphene to be applied in electronic semiconductors and related applications. Meanwhile, functionalized graphene was applied to polymer composite fibers, the tensile strength and the Young's modulus could reach 780 MPa and 19 GPa. The volume resistivity was two orders of magnitude lower than that of pure fiber. Thus, the use of ball milling to efficiently exfoliate and in situ functionalize graphite will help to develop a strategy that can be widely used to manufacture nanomaterials for various application fields.

The widespread use of graphene as a next-generation material in various applications requires developing an environmentally friendly and efficient method for fabricating functionalized graphene.

Porous NaTi2(PO4)3 Nanocubes Anchored on Porous Carbon Nanosheets for High Performance Sodium-Ion Batteries

NaTi2(PO4)3 has attracted great interest as anode material for sodium ion batteries owing to its open three-dimensional framework structure and limited volume changes during the charge and discharge process. However, the poor intrinsic electronic conductivity of NaTi2(PO4)3 needs to be improved for high rate capability. In this work, porous NaTi2(PO4)3 nanocubes anchored on porous carbon nanosheets (NaTi2(PO4)3/C) are designed and developed. This material exhibits a large discharge capacity and good rate capacity including a first discharge capacity of 485 mAh g-1 at a current density of 0.1 A g-1, and 98 mAh g-1 retained at a high rate of 4 A g-1 even after 2,000 cycles. These results suggest that NaTi2(PO4)3/C is a promising anode material for sodium-ion batteries.

An ultrathin 2D semi-ordered mesoporous silica film: co-operative assembly and application

A novel ultrathin silica film with semi-ordered fingerprint-like mesopores is synthesized with the aid of the dual templates of graphene oxide (go) and tri-block copolymer P123.

Graphene-supported binary active Mn0.25Co0.75O solid solution derived from a CoMn-layered double hydroxide precursor for highly improved lithium storage

Graphene-supported binary active solid solution (Mn_0.25Co_0.75O) is derived from CoMn-layered double hydroxide/graphene oxide precursor. Electrochemical test shows the highly improved electrochemical performances of the composite.

Preparation of a Sb/Cu2Sb/C composite as an anode material for lithium-ion batteries

Sb/Cu₂Sb/C composites are synthesized via a thermolysis approach with copper citrate and antimony acetate as precursors, respectively.