High-efficient piezocatalytic hydrogen evolution by centrosymmetric Bi2Fe4O9 nanoplates

Exploring the manifold possibilities of energy conversion mechanisms to realize versatile catalytic reactions, particularly for clean energy, is highly desirable. In this work, Bi2Fe4O9 nanoplates with a centrosymmetric structure are discovered to have unprecedently high piezoelectric catalytic performance in H2 evolution (1058 µmol·g−1·h−1 in pure water and 5723 µmol·g−1·h−1 in 10% Methanol) and degradation of organics. A new perspective is proposed to explain the observed piezoelectric catalysis, that this piezoelectric property could have originated from the existence of local dipoles on exposed surfaces, originating from the non-centrosymmetric ligands in unit cells, as corroborated by synchrotron powder diffraction and Raman spectroscopy. The piezoresponse induced by the surface piezoelectric effect in Bi2Fe4O9 nanoplates has been verified by the 1st and 2nd harmonic piezoresponse measured by piezoelectric force microscopy (PFM) and visualized by fabricating energy conversion device. This work broadens the material candidates for piezoelectric catalysis from traditional piezoelectric materials to nanomaterials with centrosymmetric structures.