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 (η 10 = 23 mV). Attractively, the siloxene-p-Pt-2 h has been applied as a HER catalyst in a Zn-H 2 O 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-H 2 O 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. Two dimensional siloxene containing abundant functional groups was demonstrated as an effective support to load ultralow platinum nanoparticles (0.56 wt%), which shows superior HER performance in both Zn-H 2 O cells and water electrolysis attributing to the excellent hydrophilia of siloxene and the faster carrier mobility as well as the suitable value of hydrogen Gibbs free energy (ΔG H*). [Display omitted] • A novel strategy to facilely synthesize siloxene-p-Pt catalysts is developed. • Siloxene-p-Pt exhibits excellent HER activity in water splitting and Zn-H 2 O cells. • Hydrogen co-evolutions from Zn-H 2 O cells-powered water splitting is constructed. • The strong electronic interaction and hydrophilia of siloxene enhance HER activity. [ABSTRACT FROM AUTHOR]