Tunable hydrogen evolution activity by modulating polarization states of ferroelectric BaTiO₃

Abstract

Switchable polarization in ferroelectric catalysts shows promise to overcome Sabatier limitation imposed on traditional catalysts. However, a comprehensive understanding of the polarization effect on the electrocatalytic performance remains elusive. In...

Electronic and electrocatalytic properties of PbTiO3: unveiling the effect of strain and oxygen vacancy

“…The HER over-potential seems better than that found for the BaTiO 3 slab modulated by polarization states. 70,104 This finding can be supported by the experimental finding of ref. 17, where the experimental evidence shows that the oxygen vacancies in PbTiO 3 show the spontaneous formation of active sites during preparation pro-…”

“…This electrochemical instability is also mentioned in. 101 In fact, the strong acid environment of this thermodynamic state is not desirable for pH-universal HER catalysis, 70 which favors rather the study of TiO 2 -terminated surfaces for such a mechanism. Therefore, due to the fact that catalytic stability is an important figure of merit for a stable catalyst, only the TiO 2 -terminated surface will be considered for the rest of the study.…”

“…It is noticeable that to have adequate polarization, the GGA+ U has been used to relax the ferroelectric surfaces. Obviously, in this work, the polarization is fixed to out-of-plane downward polarization 70 to untangle and capture the essence of the effect of the strain on the catalytic properties of the investigated structures. The bulk region has been chosen to be two lattice constants thick.…”

The Effect of Chemical Environment and Temperature on the Domain Structure of Free‐Standing BaTiO3 via In Situ STEM

“…[ 4 , 10 , 11 , 12 ] Importantly, the relationship between the chemical environment (atmospheric adsorbates) and ferroelectric polarization is two sided: i) the (polar) domains can significantly influence the local surface potential and surface free energy, thus, influencing the chemistry at the ferroelectric's surface, and ii) the chemical environment can provide charged species which can be used to control the polarization orientation and domain switching. [ 1 , 13 , 14 ] It is crucial to understand both aspects of this relationship to effectively control the properties and behavior of ferroelectric materials for their development towards novel applications aimed at electrochemistry and controllable surface chemical reactions, [ 15 ] which have shown promising for applications such as water splitting, and piezo‐catalysis. [ 16 , 17 , 18 , 19 , 20 ] This is a complex phenomenon and the current understanding of this remains an open theoretical and experimental challenge.…”