Piezovoltaics from PdH_x

Abstract

Metal hydrides have wide applications in energy science. A large pressure gradient propels the hydrogen atoms out. A piezovoltaic device, a pressure gradient-driven battery, can therefore be realized when the migrations of protons and electrons are separated by different conductors. Here we investigate the piezovoltaic performance of PdH x with various proton conductors as electrolytes and experimentally detect an output current of ≲40 nA and a voltage of ∼0.8 V for a 3 μg sample. We also demonstrate the escape of hydrogen atoms from a palladium lattice under an increasing pressure gradient using X-ray diffraction. The relationship between piezovoltaics (chemical process) and piezoelectricity (physical process) is like that between a chemical battery and a capacitor. Our work demonstrates the piezovoltaic application of metal hydrides and provides a new way to convert mechanical energy into electrical energy.

Electron Spin‐Dependent Electrocatalysis for the Oxygen Reduction Reaction in a Chiro‐Self‐Assembled Iron Phthalocyanine Device

“…One of the contributing factors to the activation energy that limits the ORR is the spin‐inversion of the spin‐state (double α ‐spin) of the paramagnetic O 2 , and it is necessary to achieve the diamagnetic states of the expected ORR products [18] . On the other hand, it has been reported in experimental and computational approaches that the Fe spin‐state is influenced differently by the adsorption of different ligands [30,41,42] . In this direction, Figure 5b displays a proposed electronic model for the spin‐state of the L/D‐FePc‐O 2 adducts series showing the electron‐spin that should be involved in the first ET for ORR to obtain the CTI .…”

“…[18] On the other hand, it has been reported in experimental and computational approaches that the Fe spin-state is influenced differently by the adsorption of different ligands. [30,41,42] In this direction, Figure 5b S2. DC spectra analysis supports the spinfilter model, with the 1 L/D-enantiomer rotating light-plane in the opposite direction to longer enantiomers, Figure 2a.…”