Multifunctional ferroelectric catalysis for water splitting: classification, synergism, strategies and challenges

People are looking for alternative and clean energy sources to replace the fossil energy. H2, as a green fuel with high combustion value, has been produced via photocatalytic by semiconductors. However, electron-hole pairs' recombination limits their further improvement. In recent years, ferroelectrics have emerged as multifunctional catalysts for suppressing electron-hole pair recombination, greatly improving the utilization of clean energy due to their unique spontaneous polarization. This review evaluates the major progress of ferroelectric multi-energy/coupled-catalysis water splitting. According to inputting energies, ferroelectric catalysis can be divided into three types: photo-catalysis, piezo-catalysis, and pyro-catalysis, which are introduced separately. The characteristics of various catalytic types are discussed in detail. The factors affecting the multi-energy catalysis water splitting are summarized. Finally, the opportunities and challenges of ferroelectric catalysis water splitting are discussed.