Chemical purification of detonation-synthesized nanodiamond: Recycling of H2SO4 and optimization of process parameters. (December 2019)

• Record Type: Journal Article
• Authors: Ha, Sangwook; Pyo Hong, Seung; Lee, Minjae; Lee, Sunmook; Lee, Seung Whan
• Is Part Of: Materials today communications. Volume 21(2019)
• Publication Date: 2019-12
• Subjects: Detonation-synthesized nanodiamond -- Chemical purification -- Recycling process -- KMnO4/H2SO4; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2019.100571
• Languages: English
• ISSNs: 2352-4928

Abstract

Graphical abstract: Highlights: Chemical purification of DND soot using KMnO4 /H2 SO4 and recycling process of H2 SO4 . Controlling the sp 3 /sp 2 carbon ratio through the reaction temperature, KMnO4 loading, and processing time. Optimizing the process parameters to prevent the formation of byproducts such as K1.33 Mn8 O16, MnO2, and MnSO4 ·H2 O. Abstract: A concept for preventing or minimizing the generation of chemical waste during the chemical purification of detonation-synthesized nanodiamond (DND) is proposed and evaluated in the chemical purification of DND with KMnO4 /H2 SO4, where the chemical oxidant can be refilled and the carrier acid may be reused. We find that the reaction temperature plays a key role to eliminate the secondary metal contaminations in the purified DND powder caused by oxidant: (i) KMnO4 remains as a residue in the forms of K1.33 Mn8 O16 or MnO2 at relatively low reaction temperatures such as 190 or 230 °C, and (ii) no residues of KMnO4 are observed at relatively high temperatures such as 330 °C. Moreover, the recycled H2 SO4 does not influence on the sp 3 /sp 2 carbon ratio and we can successfully control of sp 3 /sp 2 carbon ratio by the process parameters including the reaction temperature, KMnO4 loading, and processing time.