Scanning transmission electron microscopy analysis of Ge(O)/(graphitic carbon nitride) nanocomposite powder

作者：Kawasaki Masahiro; Sompetch Kanganit; Sarakonsri Thapanee^*; Shiojiri Makoto

来源：Materials Characterization, 2015, 110: 60-67.

DOI：10.1016/j.matchar.2015.10.015

• Analytical electron microscopy
• Germanium
• Graphitic carbon nitride
• Synthesis
• Li-ion battery

Analytical electron microscopy has revealed the structure of particles that were synthesized by chemical reaction of GeO2 with NaBH4 in the basic solution including graphitic carbon nitride (g-C3N4) powders. The g-C3N4 was arranged by recrystallization of melamine at 600 degrees C under N-2 gas atmosphere. The samples were dried at 60 degrees C or 180 degrees C for 4 h. The g-C3N4 was observed as lamellae of several ten nm or less in size and had an amorphous-like structure with a distorted lattice in an area as small as a few hundred pm in size. The reaction product was Ge(O) particles as fine as several nm in size and composed of Ge and 0 atoms. Most of the particles must be of GeO2-x with the amorphous-like structure that has also a distorted lattice in an area of a few hundred pm in size. In the sample dried at 60 degrees C, the particles were found to be dispersed in a wide area on the g-C3N4 lamella. It is hard to recognize those particles in TEM images. The particles in the sample dried at 180 degrees C became larger and were easily observed as isolated lumps. Hence, these powders can be regarded as GeO2/g-C3N4 or Ge/GeO2/g-C3N4 nanocomposites, and expected to be applicable to anode materials for high energy Li-ion batteries due to Ge catalysis effect, accordingly.

• 出版日期2015-12