Although intensive efforts have been made and great progress has been achieved relating to the electrocatalytic hydrogen evolution reaction (HER), an advanced synthesis strategy for an efficient electrocatalyst is still the most significant goal. In this paper, we introduce PdFeCoNiCu high-entropy alloy (HEA) nanoparticles as an efficient electrocatalyst for the HER, which has been prepared in an oil phase under facile conditions for the first time. PdFeCoNiCu/C shows excellent alkaline HER catalytic performance with an overpotential of only 18 mV and a Tafel slope of 39 mV dec⁻¹. Meanwhile, we achieved the highest mass activity (6.51 A mg_Pd ⁻¹ at −0.07 V vs. RHE) in the alkaline HER among all non-Pt electrocatalysts. PdFeCoNiCu/C also shows surprisingly stable catalytic properties for over 15 days without notable decay. Based on theoretical calculations, the HEA surface demonstrates the optimization of electronic structures based on a synergistic effect between all metals. Pd and Co are confirmed to be the dominant electroactive sites for both H₂ formation and initial water splitting, which are assisted by Ni, Fe, and Cu promotion, enhancing electron transfer and optimizing the binding energies of hydrogen intermediates. This work has supplied significant insight into the design of an efficient electrocatalyst based on HEA materials.

A Eu³⁺ functionalized zinc metal–organic framework (Eu@Zn-MOF) has been prepared by the post-synthetic modification method and innovatively used to construct a ratiometric fluorescent probe for tetracycline detection.

Surface-selenized RuO₂/C (RuO₂-Se_0.18/C) exhibits a high NH₃yield rate (12.97 μg h⁻¹cm⁻²) at low overpotential. The superior NRR performance is attributed to the effects (on N₂adsorption, surface hydrogenation, N₂activation and NH₃desorption) of surface selenization.