Hollow Platinum Nanospheres and Nanotubes Templated by Shear Flow-Induced Lipid Vesicles and Tubules and Their Applications on Hydrogen Evolution

Shear rate was utilized for synthesis of 1,2-bis­(10,12-tricosa­diy­noyl)-sn-glycero-3-phospho­choline (DC8,9PC) vesicles and tubules in a microfluidic device. Lipid vesicles and tubules as templates were exploited to fabricate hollow platinum nanospheres and nanotubes, respectively, for the first time in a mild manner. The Pt nanosphere is ∼190 nm in diameter with wall thickness of ∼32 nm. The Pt nanotube is ∼280 nm in diameter and ∼30 μm in length with wall thickness of ∼15 nm. The Pt nanospheres and nanotubes as hydrogen evolution reaction (HER) catalysts both exhibited all-time high HER catalytic activity, with overpotentials of 31 and 27 mV at current densities of 10 mA cm–2 and Tafel slopes of 23 and 21 mV dec–1 respectively, in acidic electrolytes. The values of the exchange current density of Pt nanosphere and Pt nanotube catalysts are obtained as 0.87 and 0.93 mA cm–2 by extrapolating the Tafel plot, which are larger than that of commercial Pt/C catalyst. Their catalytic activity can be maintained for at least 19 h.