The one-dimensional carbon chain is extremely unstable. In order to solve the problem of the stability of the carbon chains, we have previously synthesized the carbon chains with a world record length inside carbon nanotubes by high-temperature annealing of double-walled carbon nanotubes (Shi L., et al. Nature Materials, 15, 634- 639, 2016). On this basis, we then used single-walled carbon nanotubes converted into double-walled carbon nanotubes of different diameters as templates to synthesize the carbon chains with controllable properties (Shi L., et al. Nano Letters, 21, 1096 –1101, 2021). However, since the diameter distribution of the applied carbon nanotube is till broad and not controllable, there are still challenges for the controlled synthesis of the carbon chains with certain property.

    Previously, we tried to synthesize inner tubes inside single-walled carbon nanotubes using in-situ laser annealing (Chimborazo L., et al. Applied Physics Letters 115, 103102, 2019). On this basis, in this paper we heated the sample with a laser with a wavelength of 568 nm under the Raman spectrometer lens. The sample was prepared by using double-walled carbon nanotubes dispersed on TEM grid with markers, and the growth of carbon chains can be monitored in-situ by Raman spectroscopy during the synthesis. Since the annealing position is marked, and the position of the heated sample can be easily found in the electron microscope for measurement, so the carbon chain grown after the laser heating can be observed in the electron microscope.

    The illustration of the paper was selected as front cover of the Carbon (Vol. 183).

    Paper information: Photothermal synthesis of confined carbyne. Carbon; 182, 348–353 (2021) Lei Shi*, Ryosuke Senga, Kazu Suenaga, Johnny Chimborazo, Paola Ayala, Thomas Pichler*.