Investigation of the surface properties and the hydrogen evolution reaction, HER, at thermal rhodium oxide electrodes

Understanding the Activation Mechanism of RhCrOx Cocatalysts for Hydrogen Evolution with Nanoparticulate Electrodes

“…The Rh 3d peaks obtained from the CrO x /RhNP sample (without annealing treatment) correspond to the Rh 0 metal, with the BE peaks centered at 306.5 eV for Rh 3d 5/2 and 311.2 eV for Rh 3d 3/2 . The spin–orbital separation of the BE (ΔBE) between Rh 3d 5/2 and Rh 3d 3/2 in CrO x /RhNP (4.7 eV) is consistent with that reported in the literature. ,− Additionally, in the samples annealed at 500 °C, regardless of the presence of Cr, the HR-XPS peaks of RhO x and RhCrO x shifted to a higher BE compared to the samples without annealing treatment. The RhO x and RhCrO x samples exhibited the HR-XPS peaks at 307.6 eV for Rh 3d 5/2 and 312.3 eV for Rh 3d 3/2 , respectively, with no significant difference between them.…”

“…These HR-XPS peaks were consistent with those reported in the literature and could be assigned to Rh 3+ (derived from Rh 2 O 3 ). 48,49 The results of peak fitting for the Rh 3d HR-XPS spectra indicate that the RhO x and RhCrO x samples were all composed of Rh 3+ species (Figure S6a,b). In contrast, both the bare RhNP/FTO and CrO x /RhNP/FTO (without annealing) contained Rh 3+ species with a surface concentration ratio of Rh 0 :Rh 3+ = 3:2, as revealed by quantitative XPS analysis (Figure S6c,d and Table S1).…”

Clean rhodium nanoparticles prepared by laser ablation in liquid for high performance electrocatalysis of the hydrogen evolution reaction

“…Rh(I)-Rh(III). 7,22 In the backward scan, two cathodic peaks are observed at E pc ¼ 0.60 and 0.32 V vs. RHE, and attributed to stepwise reduction of higher oxidized states to Rh(0). 22 The electrochemical surface area (ESA) of the electrodes was evaluated by anodic CO stripping, [23][24][25] by comparing the cyclic voltammetries (0.5 M H 2 SO 4 , 20 mV s À1 ) under argon saturated solution of the electrodes before and aer exposure treatment with CO (Fig.…”

“… 7,22 In the backward scan, two cathodic peaks are observed at E pc = 0.60 and 0.32 V vs. RHE, and attributed to stepwise reduction of higher oxidized states to Rh(0). 22 …”