Developing high-performance electrocatalysts for hydrogen evolution reaction (HER) is crucial for sustainable hydrogen production, yet still challenging. Here, we report boron-modulated osmium (B-Os) aerogels with rich defects and ultra-fine diameter as a pH-universal HER electrocatalyst. The catalyst shows the small overpotentials of 12, 19, and 33 mV at a current density of 10 mA cm−2 in acidic, alkaline, and neutral electrolytes, respectively, as well as excellent stability, surpassing commercial Pt/C. Operando X-ray absorption spectroscopy shows that interventional interstitial B atoms can optimize the electron structure of B-Os aerogels and stabilize Os as active sites in an electron-deficient state under realistic working conditions, and simultaneously reveals the HER catalytic mechanisms of B-Os aerogels in pH-universal electrolytes. The density functional theory calculations also indicate introducing B atoms can tailor the electronic structure of Os, resulting in the reduced water dissociation energy and the improved adsorption/desorption behavior of hydrogen, which synergistically accelerate HER.
3 October 2021 in Journal of the American Chemical Society
Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling the nuts and bolts of solar hydrogen production. We report the use of Au@Cu7S4 yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable hydrogen production under visible and near infrared illumination. Ultrafast spectroscopic data reveal the prevalence of long-lived charge separation states for Au@Cu7S4 under both visible and near infrared excitation. Combined with the advantageous features of yolk@shell nanostructures, Au@Cu7S4 achieves a peak quantum yield of 9.4% at 500 nm and a record-breaking quantum yield of 7.3% at 2200 nm for hydrogen production in the absence of additional co-catalysts. The design of a sustainable visible- and near infrared-responsive photocatalytic system is expected to inspire further widespread applications in solar fuel generation. In this work, the feasibility of exploiting the localized surface plasmon resonance property of self-doped, nonstoichiometric semiconductor nanocrystals for the realization of wide-spectrum-driven photocatalysis is highlighted.