Scheme 3. Classification of various Ru NMs reported to date (2005–2019), on the basis of their synthesis strategy. Abbreviations: carbon nanotube (CNT), activated carbon (AC), oxidized activated carbon (OAC), carbon black (CB), nanoalloys (NAs), nickel foam (NiF), (N,P,C)-doped (NPC), indium tin oxide over glass substrate (ITO-Gs), doped over (@).7–11,19,45a,55,56,59,104.
