Fig. 3: LSPR-mediated charge kinetics of Ag NWs/CC at the liquid junction with H₂O₂ in PBS.

a CV curves of Ag NWs/CC (red solid and black dashed lines) and bare CC (blue solid and cyan dashed lines) as the working electrodes collected without solar irradiation in the PBS electrolyte with (solid lines) and without (dashed lines) 8 mM H₂O₂. b CV curves of Ag NWs/CC as the working electrode measured in the PBS electrolyte with 8 mM H₂O₂ in the dark (dashed line) and under solar illumination (solid line). c, d Temporal current responses measured at an external bias of −0.2 V (vs. Ag/AgCl) in the PBS electrolyte with 8 mM H₂O₂ for c Ag NWs/CC and d Ag thin film/FTO as the working electrode under chopped solar radiation. e Schematic illustrations of (first panel) applied-bias-driven electron transfer (blue arc arrow) from Ag NWs/CC to H₂O₂; (second panel) excitation of LSPR of Ag NWs by incident sunlight (colorful wave); (third panel) LSPR dephased through the Landau mechanism giving rise to hot electrons in Ag NWs; and (fourth panel) energetic electrons derived from parental hot electrons via energy spread by means of electron–electron scattering and the subsequent injection (blue horizontal arrow) into H₂O₂. f Schematic illustrations of (first panel) external-bias-driven electron transfer (blue arc arrow) from Ag thin film/FTO to H₂O₂ and (second panel) incident sunlight (colorful wave) (third panel) scattered by Ag thin film/FTO, in which UV light (purple wave) results in transitions (black dashed arrow) of the electron from the HOMO to the LUMO of H₂O₂, which is then photolyzed via transfer of excited electrons to the Ag thin film/FTO working electrode (upper blue arc arrow). E_F: Fermi level of the Ag NWs/CC and the Ag thin film/FTO working electrodes dictated by the external bias at −0.2 V (vs. Ag/AgCl); \({{E}}_{{\rm{F}},{\rm{H}}_2{\rm{O}}_2/{\rm{H}}_2{\rm{O}}}\): reaction potential of the formal H₂O₂ electroreduction; \({{E}}_{{\rm{F}},{\rm{H}}_2{\rm{O}}_2/{\rm{H}}_2{\rm{O}} ({\rm{Autocat}}.)}\): reaction potential of the autocatalytic H₂O₂ electroreduction. Symbols alongside \({{E}}_{{\rm{F}},{\rm{H}}_2{\rm{O}}_2/{\rm{H}}_2{\rm{O}}}\) and \({{E}}_{{\rm{F}},{\rm{H}}_2{\rm{O}}_2/{\rm{H}}_2{\rm{O}} ({\rm{Autocat}}.)}\) are employed to emphasize the Gaussian distribution of the energy states of H₂O₂ as the electron acceptor in the formal and autocatalytic electroreduction reactions, respectively.