Fabricating Nanodiamonds from Biomass by Direct Laser Writing under Ambient Conditions

Abstract

Commercial nanodiamonds (NDs) are usually produced by detonation and chemical vapor deposition. While these methods normally require either the application of extreme temperatures/pressures or expensive and hazardous gaseous/ chemical precursors, in this study, NDs were produced on paper made from nanolignin/cellulose nanofibrils (LCNF) composite film by means of direct laser writing at ambient temperature and air pressure. The generation of NDs was found to depend largely on high laser power. Graphene nanoribbons and carbon nanoonions were obtained at lower laser power as acceptable products. As cellulose nanofibrils were unsuccessfully lased in this study, the effects of diverse components of LCNFs were investigated. Results showed that a suitable cellulose content in LCNFs can accelerate laser carbonization, while an excessive oxygen content component will lead to the combustion of LCNFs in air. Moreover, it was found that a higher lignin content was essential for the formation of NDs. Individual nanolignin particles were able to be converted into NDs. However, this lasing process needed a higher-power laser than that did that from LCNF. Considering the abundance and renewability of LCNFs, the direct laser writing technique provides a simple, inexpensive, and environmentally friendly method for the synthesis of NDs and the fabrication of paper-based carbon patterns from biomass, which is both inexpensive and readily available.

Fabricating Graphene and Nanodiamonds from Lignin by Femtosecond Laser Irradiation

“…This transformation phenomenon was also observed in our previous research on the formation of NDs from LCNFs. 16 The generation of NDs from nanolignin was found at 900 mW in this study, much higher than that from LCNFs at 600 mW. This confirmed our inference about the positive role of cellulose nanofibrils in the biomass−ND conversion.…”

“… 24 , 25 , 32 It is impressive that we have fabricated circuit patterns from nanolignin/cellulose nanofibril composites, showing promising applications as flexible electrics and sensors. 16 Since the patterns in this study contained graphene and ND microstructures and showed varying degrees of resistances in the following discussion, it was reasonable that these patterns can be applied for fabricating electric devices.…”

“…A large number of carbon spheres were generated at 900 mW, as shown in Figure 3 d, which were similar to the results of the preparation of NDs from the LCNF composite by femtosecond laser irradiation in our previous study. 16 However, owing to the more active aliphatic carbon, LCNFs degraded much faster and easier than nanolignin. The obvious bubble formation in Figure 3 a was not found in the conversion from LCNFs to NDs.…”

“… 15 Our previous work has demonstrated the conversion from nanolignin/cellulose nanofibril (LCNF) composite films to NDs by laser direct writing and indicated that the lignin content played a major role in the generation of NDs. 16 However, no more detailed studies have yet been reported on the carbonization mechanism of pure lignin nanoparticles for ND synthesis in laser irradiation.…”

“…To date, very few studies were reported on the synthesis of NDs from biomass, although diamond-like carbon nanofoam was prepared by hydrothermal carbonization from sucrose/naphthalene solution, and diamond structures could be found among pyrolytic graphite layers and onion-like particles after wood charcoal was carbonized at 700 °C . Our previous work has demonstrated the conversion from nanolignin/cellulose nanofibril (LCNF) composite films to NDs by laser direct writing and indicated that the lignin content played a major role in the generation of NDs . However, no more detailed studies have yet been reported on the carbonization mechanism of pure lignin nanoparticles for ND synthesis in laser irradiation.…”