Plasmon driven super-high HER activity of electronic structure and lattice strain engineered single atomic layer Pd@Au nanorods.

[Display omitted] • The ML-Pd@Au NRs catalyst shows super-high HER activity and ultra-low overpotential under irradiation. • Au NRs not only adjust the electronic structure and lattice strain of Pd but also offer plasmonic hot charge carriers. • The method to synthesize the single atomic layer Pd@Au NRs catalyst is simple, gentle, and accurate. The development of efficient catalysts with low energy consumption has always been a key issue for sustainable hydrogen energy. Here, we report a catalyst comprising a single atomic Pd layer deposited on Au nanorods (ML-Pd@Au NRs) that shows a super-high HER activity and ultra-low overpotential under localized surface plasmon resonance condition. The Au NR plays triple determining roles in HER performance via adjusting the electronic structure and lattice strain of Pd that effectively reduces the adsorption energy of H-adatoms, eliminating the penetration of H adatoms in multilayer Pd crystal that decreases the H adatoms diffusion kinetics, and providing high energetic hot charge carriers under near-IR light irradiation that decreases the activation energy and onset potential of HER. The single atomic Pd layer on Au NRs ensures the hot electron transfer as the main dissipation pathway of the plasmonic hot charge carriers for HER. Thus, under near-IR light irradiation, HER on ML-Pd@Au NRs occurs with a high mass activity of 17.47 mA mg−1 at 100 mV and a very low overpotential of 13 mV at 10 mA cm−2, which are superior to the commercial Pd/C and commercial Pt/C catalysts under the same conditions. [ABSTRACT FROM AUTHOR]