Carbon-based nanomaterials, such as C60 fullerenes, are expected to accumulate in soils and sediments. Although little is known about their environmental fate, these nanoparticles may be susceptible to photochemical and microbial degradation. In the present work, C60 spiked onto a glass surface or added to silicon dioxide or sandy soil was exposed to UV light. Upon UV exposure, the fullerenes were degraded in all the treatments and the decay followed a pseudo-first-order rate law. In the absence of a matrix, the half-life of C60 was 13.1 days, with an overall degradation of 45.1% that was accompanied by the formation of functionalized C60-like structures. Furthermore, LC-MS analysis highlighted the presence of a large number of fulleroid products that were not directly related to the irradiation and showed opened cage structures and various degrees of oxidation. When C60 was spiked onto solid matrices the degradation occurred at a faster rate (with half-lives of 4.5 and 0.8 days for silicon dioxide and sandy soil, respectively) and minor but consistent losses were found in the non-irradiated samples, presumably due to biotic processes and/or a matrix effect in these samples. The results of this study suggest that light-mediated transformation of the fullerenes will occur in the environment and that an accurate assessment of their fate is complicated by the large number of products that may be formed.

Degradation of solid state C60 fullerene by UV irradiation under environmentally relevant conditions

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.