Enhanced hydrogen evolution reaction in Sr doped BiFeO_3 by achieving the coexistence of ferroelectricity and ferromagnetism at room temperature

摘要

The perovskite transition metal oxide(TMO) has been considered in electrocatalysis for the modern clean energy technologies as its high electrochemical activity and low cost. The atomic scale engineering to the local stoichiometry of single crystal TMO provides a clue of the relation between electronic structure and catalytic performance. Here we report a hydrogen evolution reaction(HER) activity enhancement ~ 1761% of Bi_(0.85)Sr_(0.15)FeO_3 compared to the pure BiFeO_3. By the systemic investigation of the Sr doping level of Bi_(1-x)Sr_xFeO_3(BSFO), it is found that the HER enhancement originates from the improvement of ferromagnetism of BSFO without obvious scarification of the ferroelectricity at the room temperature. The multiple ferroic orderings in BSFO are beneficial for HER activity, which offers the strengthen of hybridization of Fe 3d and O2 p orbitals from the view of ferromagnetism, and the assistance of electron drift by spontaneous electric polarization. Our study not only affords the strategy of developing multiple ferroic orderings in TMO, but also facilitates the atomic scale understanding of the improved HER activity.