Manipulation of charge transport in ferroelectric-semiconductor hybrid for photoelectrochemical applications

Manipulation the charge transport and energy band of a semiconductor is always an important theme for photoelectrochemistry. Here we design and fabricate a ferroelectric-semiconductor hybrid structure for photoelectrochemical applications. By selecting the appropriate poled bias, the polarization direction of ferroelectric could be conveniently manipulated for n-type semiconductors (TiO2 and ZnO) and p-type semiconductors (g-C3N4 and Bi2Mo2O9). The photocurrents of the hybrid photoanodes (at 1.23 V vs. RHE) and photocathodes (at 0 V vs. RHE) enhanced by 60 +/- 5% and 85 +/- 15% with water oxidation and reduction respectively under the illumination of a monochromater (lambda = 365 nm). Further, the efficiency of oxidation kinetics for hybrid photoanodes increased by 1.5 fold, and the charge transport time reduced 10-15%. The polarized ferroelectric blended in semiconductor may have an effect on the space charge region of the semiconductors, further, bending the energy band and accelerating the charge transport at the photoelectrode surface. This research has a certain reference for developing hybrid photoelectrodes relevant to the large-scale application of ferroelectric materials in solar water splitting, photovoltaic, and solar fuels devices.