Does the oxophilic effect serve the same role for hydrogen evolution/oxidation reaction in alkaline media?

Identifying the Transfer Kinetics of Adsorbed Hydroxyl as a Descriptor of Alkaline Hydrogen Evolution Reaction

“…On the other hand, for the OH À generated from OH ad + e À Q OH À (denoted as OH ad -transferred OH À ), its desorption ability also influences the OH ad transfer, which is closely related to the surface charge properties of the catalyst. [16] Zeta potential is capable of reflecting the chargeability of the catalyst surface, and it therefore could help us to deeply understand the interaction between Ni/Co-MoSe 2 and OH ad -transferred OH À . As clearly revealed by Figure 3 c, the more negative potential (À23.6 mV) in 0.1m KOH for Ni-MoSe 2 in comparison with Co-MoSe 2 (À21.4 mV) manifests its more negative surface charges.…”

“…As clearly revealed by Figure 3 c, the more negative potential (À23.6 mV) in 0.1m KOH for Ni-MoSe 2 in comparison with Co-MoSe 2 (À21.4 mV) manifests its more negative surface charges. Accordingly, the desorption of OH ad -transferred OH À from the Ni-MoSe 2 surface into the bulk electrolyte may be much easier due to stronger repulsive force and/or special adsorbed OH À -induced steric effects, [16,17] thus accelerating the transfer from OH ad to OH À . [4,16] To further confirm the close correlation between the surface chargeability and catalytic activity of Ni/Co-MoSe 2 in alkaline medium, we also tested the zeta potentials and HER polarization curves of Ni/Co-MoSe 2 in other concentrations of KOH (0.01m and 1m).…”

“…Accordingly, the desorption of OH ad -transferred OH À from the Ni-MoSe 2 surface into the bulk electrolyte may be much easier due to stronger repulsive force and/or special adsorbed OH À -induced steric effects, [16,17] thus accelerating the transfer from OH ad to OH À . [4,16] To further confirm the close correlation between the surface chargeability and catalytic activity of Ni/Co-MoSe 2 in alkaline medium, we also tested the zeta potentials and HER polarization curves of Ni/Co-MoSe 2 in other concentrations of KOH (0.01m and 1m). As disclosed in Figure 3 c, the absolute value of the zeta potential for both Ni/Co-MoSe 2 catalysts gradually increases with the KOH concentration, increasing from 0.01 to 1m.…”

Identifying the Transfer Kinetics of Adsorbed Hydroxyl as a Descriptor of Alkaline Hydrogen Evolution Reaction

“…As clearly revealed by Figure c, the more negative potential (−23.6 mV) in 0.1 m KOH for Ni‐MoSe 2 in comparison with Co‐MoSe 2 (−21.4 mV) manifests its more negative surface charges. Accordingly, the desorption of OH ad ‐transferred OH − from the Ni‐MoSe 2 surface into the bulk electrolyte may be much easier due to stronger repulsive force and/or special adsorbed OH − ‐induced steric effects, thus accelerating the transfer from OH ad to OH − . To further confirm the close correlation between the surface chargeability and catalytic activity of Ni/Co‐MoSe 2 in alkaline medium, we also tested the zeta potentials and HER polarization curves of Ni/Co‐MoSe 2 in other concentrations of KOH (0.01 m and 1 m ).…”

“…Therefore, it can be rationally deduced that the introduced Ni atoms could effectively optimize the interaction between MoSe 2 and OH ad so that it is neither too strong nor too weak, thus accelerating the transformation from the intermediate OH ad (generated from the water‐dissociation step H 2 O ⇄ H ad + OH ad ) to OH − in the Volmer process of alkaline HER. On the other hand, for the OH − generated from OH ad + e − ⇄ OH − (denoted as OH ad ‐transferred OH − ), its desorption ability also influences the OH ad transfer, which is closely related to the surface charge properties of the catalyst . Zeta potential is capable of reflecting the chargeability of the catalyst surface, and it therefore could help us to deeply understand the interaction between Ni/Co‐MoSe 2 and OH ad ‐transferred OH − .…”