Hierarchical VSe2-doped NiCoSex yolk-shelled porous prisms as enhanced bifunctional catalytic materials for highly efficient photovoltaics and hydrogen evolution

Abstract

Herein, a facile assembly strategy and ion exchange reaction coupled with the following selenization treatment have been developed for the synthesis of V-doped transition metal nickel-cobalt selenide prism with hierarchical yolk-shelled structure (named as VSe2-NiCoSex), which have the outer shell of Ni–Co–VSe2 with the Ni–CoSe2 inner core. Notably, VSe2-NiCoSex presented prominent bifunctional electrocatalytic performances and excellent conductivity toward both dye-sensitized solar cells (DSSCs) and hydrogen evolution reactions (HERs) for water electrolysis. As for DSSCs, VSe2-NiCoSex electrode exhibited a remarkable power conversion efficiency (PCE) of 9.50%, Rct of 1.09 Ω and Epp of 231 mV than that of Pt (8.29%, 4.25 Ω and 414 mV) under the same testing conditions. Besides, VSe2-NiCoSex as HER catalyst delivers a lower overpotential of 84.3 mV at the current density of 10 mA cm−2 and a small Tafel slope of 49.1 mV dec−1 in 0.5 M H2SO4.