Fig. 2: SEM images, XRD pattern, and Raman spectrum of sub-micro/microscale particles produced in supercritical acetone.
From: Precursor-free synthesis of carbon quantum dots and carbon microparticles in supercritical acetone
a SEM image of particles. The synthetic temperature, synthetic time, and molar volume were 450 °C, 0.5 h, and 2.75 × 10−4 m3 mol−1. The scale bar represents 10 µm. b SEM image of particles. The synthetic temperature, synthetic time, and molar volume were 450 °C, 1 h, and 2.75 × 10−4 m3 mol−1. The scale bar represents 10 µm. c SEM image of particles. The synthetic temperature, synthetic time, and molar volume were 450 °C, 2 h, and 2.75 × 10−4 m3 mol−1. The scale bar represents 10 µm. d XRD pattern of the particles. The particles were synthesised under the conditions of 450 °C, 2 h, and 2.75 × 10−4 m3 mol−1 (Fig. 2c). The wavelength of the X-ray was 0.1392 nm. The (002) diffraction peak was located at \(2\theta\) = 25.35°. e Raman spectrum of particles corresponding to Fig. 2c. The wavelength of the excitation laser was 515 nm. The D and G band peaks appeared at 1361 and 1596 cm−1. The 2D and D + G bands were also detected at 2706 and 2922 cm−1.
