Regulating the Adsorbed Hydrogen Coverage for a Good Trade-Off between Hydrogen Evolution Activity and...

For cathodic electrochemiluminescence (ECL) emission, the adsorbed hydrogen (H*_ads) generated during the hydrogen evolution reaction (HER) is a highly active intermediate. Nevertheless, the efficient utilization of H*_ads and the relationship between HER activity and ECL performance are elusive. Herein, different phases of Pd hydride metallene (PdHene) aerogels were employed as coreaction accelerators to modulate the quantity of H*_ads. Experimental and theoretical calculations verified that a volcano-shaped relationship exists between HER performance and ECL signal. The mixed-phase PdHene aerogels have moderate H*_ads coverage and facilitate the adsorption and cleavage of O-O bonds of H₂O₂, thereby enhancing ^•OH production and resulting in a 2-fold increase in the ECL signal compared to that of Pdene aerogels. Finally, an ECL aptasensor for the sensitive detection of chlorpyrifos is established, which shows desirable application potential. This work builds a bridge between the HER activity and ECL performance, which aims to construct an advanced sensing platform by rationally designing HER catalysts.