Fig. 4. (a)–(f) SEM images of Cu-TCPP samples synthesized in the presence of (a) 0 μL mL⁻¹, (b) 0.3125 μL mL⁻¹, (c) 0.625 μL mL⁻¹, (d) 0.9375 μL mL⁻¹ and (e) 1.25 μL mL⁻¹ of TFA. (f) Low-magnification SEM image of C-TCPP synthesized with 0.625 μL mL⁻¹ TFA; (g) corresponding TEM image; (h) enlarged TEM image.