Strain-Induced Ferroelectric Heterostructure Catalysts of Hydrogen Production through Piezophototronic and Piezoelectrocatalytic System.

In this work, we discover a piezoelectrocatalytic system composed of a ferroelectric heterostructure of BaTiO3 (BTO)@MoSe2 nanosheets, which exhibit piezoelectric potential (piezopotential) coupling with electrocatalyzed effects by a strain-induced piezopotential to provide an internal bias to the catalysts' surface; subsequently, the catalytic properties are substantially altered to enable the formation of activity states. The H2 production rate of BTO@MoSe2 for the piezoelectrocatalytic H2 generation is 4533 μmol h-1 g-1, which is 206% that of TiO2@MoSe2 for piezophototronic (referred to as piezophotocatalytic process) H2 generation (∼2195.6 μmol h-1 g-1). BTO@MoSe2 presents a long-term H2 production rate of 21.2 mmol g-1 within 8 h, which is the highest recorded value under piezocatalytic conditions. The theoretical and experimental results indicate that the ferroelectric BTO acts as a strain-induced electric field generator while the few-layered MoSe2 is facilitating piezocatalytic redox reactions on its active sites. This is a promising method for environmental remediation and clean energy development.