Tailoring Active Sites in Mesoporous Defect-Rich NC/V-o-WON Heterostructure Array for Superior Electrocatalytic Hydrogen Evolution

• Tailoring active sites in earth-abundant non-noble metal electrocatalysts are required toward widespread applications in sustainable energy fields. Herein, an integrated mesoporous heterostructure array is reported by a hydrogenation/nitridation-induced in situ growth strategy. Highly conductive oxygen-vacancies-rich tungsten oxynitride (V-o-WON) nanorod array acts as the backbone encapsulated by ultrathin nitrogen-doped carbon (NC) nanolayers, forming high-quality shell/core NC/V-o-WON heterostructures. Density functional theory calculations reveal that defect-rich heterostructure arrays not only enhance the conductivity and modulate electronic structure but also promote the adsorption and dissociation of reactants and offer substantial potential sites. As expected, porous NC/V-o-WON array exhibits a small overpotential of 16 mV at the current density of 10 mA cm(-2) and a low Tafel slope of 33 mV per decade in alkaline media, accompanied by negligible loss upon a large current density over 100 h. Benefiting from outstanding electrocatalytic hydrogen evolution reaction performance and stability, this defective heterostructure could serve as a prominent alternative electrocatalyst for renewable energy applications.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

nanorod arrays

density functional theory

hydrogen evolution reaction

heterostructures

nitrogen-doped carbon

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