fig2

Figure 2. (A) (i) Schematic illustration of the chemical reduction method^[52]; (ii) TEM image of hollow sphere Se nanoparticles; (iii) HRTEM image of a hollow sphere Se nanoparticle; Copyright 2002, Wiley-VCH. (B) Scheme illustration of the solvent-thermal method^[64]; (i) Large-area HRTEM image and the particle size distribution of Se nanoparticles; (ii) HRTEM image of Se nanoparticles showing d spacings; Copyright 2021, American Chemical Society. (C) (i) Schematic of the laser-ablation method^[65]; (ii) TEM image of selenium nanoparticles; Copyright 2019, Springer.