Fig. 2. Optical image of PLD-2D-hBN electrode used for a voltammetric scan rate study (28 repeated scans) of 1 mM RuHex/0.1 M KCl, decorated with 6 PLDs resulting in a tree-shape defect pattern. This is due to its electrochemical application. (A) Shows the optical image overlapped with Raman mapping. (B) Shows typical Raman peak of 2D-hBN (1365 cm⁻¹), (C) shows Raman peak of a damaged area caused by the HER scanning and (D) shows the Raman peak of a physical linear defect. Higher resolution zoom in area with optical image (E), 2D Raman mapping (F) and 3D Raman mapping (G) of another area of the same PLD-2D-hBN electrode.