Surface cleaned CuxPdy alloy: Synthesis and their superior performances in hydrogen evolution reaction and biosensor

High cost and restricted activity of electrocatalysis are the major challenges for hydrogen generation and biosensors. In this work, we provided a one-pot synthesis of Cu x Pd y alloy nanoparticles (NPs) with controllable atomic ratio and “clean surface”. Benefiting from the preferable d-band structure, the Cu 62 Pd 38 NPs exhibited a lower overpotentials in the hydrogen evolution reaction (HER) over the full pH range. In the acidic media, Cu 62 Pd 38 NPs achieved a low overpotential of 28.12 mV for HER, which was 25.73% of Pd NPs. In the neutral solution, the overpotential by Cu 62 Pd 38 NPs is only 41.71% for that by uncleaned CuPd NPs. In alkaline media, the overpotential by Cu 62 Pd 38 NPs was declined from 38.01 to 20.20 mV after 720 min yielding hydrogen, which was only 53.14% for the initial overpotential. As applied in biosensor, the synergistic effect of Cu and Pd accelerated the kinetics of electrocatalytic process, resulting in an enhanced performance. The glucose sensor constructed by Cu 67 Pd 33 exhibited a wider detection range up to 100.0 mM. And the sensitivity is 379.4 µA/(mM·cm 2 ), which is ca. 4.63 and 14.09 folds for that by pure Cu NPs and Pd NPs, respectively. An optimal atomic percent would be conducive to optimize electrocatalytic activity of Cu x Pd y alloy. The volcano plots for Cu x Pd y would open up a new avenue for designing electrocatalysis with rationalized cost and optimized performance.