Modulating the photoelectrochemical (PEC) reactions on one photoelectrode is of significance to the photoelectrochemistry. Herein, we fabricate ferroelectric photoelectrode based on Pb(Zr, Ti)O-3 (PZT) without polarization that shows tunable PEC reactions in the form of ambipolar photocurrent, and demonstrate that the interesting behavior originates from the random distribution of ferroelectric domains and a selective transport mechanism of charge carriers to the surface with electrolyte under different potentials. The photoanodic current could be realized as 4.55 mu A/cm(2) at 0.8 V vs Ag/AgCl and the photocathodic current could be obtained as 16.3 mu A/cm(2) at -0.3 V vs Ag/AgCl. In addition, by inserting a thin layer of Au between PZT and FTO, the photoanodic current could be enhanced to 114 mu A/cm(2) at 0.8 V vs Ag/AgCl. This obvious enhancement is on account of the multiple effects of the contact between Au and PZT, which include the rectification effect by the formed Ohmic contact, the role of surface plasmon resonance and the reduction of the resistance. Thus, a new PEC system for tuning photoelectrochemical reactions smartly and efficiently is proposed. (c) 2019 The Electrochemical Society.