X-ray induced carbon coating on carbon nanotubes

The formation of a carbon coating on carbon nanotubes (CNTs) was observed in X-ray microscopy experiments. X-ray absorption near-edge structure (XANES) spectroscopy showed that the coating originated from the lacey carbon on the substrate, which was heated by the X-ray beam and then deposited on CNTs. The coating shows some fingerprint features around the π* peak of the C 1s XANES spectrum, which were widely observed in literature but attributed to chemical modification or interfacial interaction in carbon nanomaterials. Our results suggest that the X-ray induced coating could be a possible reason for those XANES features.