Pt NPs-loaded siloxene nanosheets for hydrogen co-evolutions from Zn-H₂O fuel cells-powered water-splitting

Siloxene features abundant functional groups and oxygen vacancies, which facilitates the ultrafine platinum nanoparticles loading for catalyzing hydrogen evolution reaction (HER). Herein, a siloxene-p-Pt-2 h composite has been fabricated with an ultralow platinum loading on siloxene (0.56 wt%), which shows greatly enhanced HER activity featuring an ultralow overpotential (eta(10) = 23 mV). Attractively, the siloxene-p-Pt-2 h has been applied as a HER catalyst in a Zn-H2O fuel cell, demonstrating a high power density of 157 mW cm(-2) in coupling with the cathode hydrogen evolution. Moreover, a coupled configuration between two Zn-H2O fuel cells in series and the cell-powered hydroxide electrolyzer achieves the efficient hydrogen co-productions co-catalyzed by the HER catalysts. The excellent HER performance is attributed to the hydrophilic character and the optimal Gibbs free energy via the strong interaction between the siloxene and platinum nanoparticles. This work provides a novel design of self-powered co-productions of hydrogen.