A Perovskite Ferroelectric KNbO3-A(Ni1/2Sn1/2)O3 for Photocatalytic Hydrogen Production (A = Ba, Sr, Ca)

In this work, [KNbO3]0.98-[A(Ni1/2Sn1/2)O3]0.02(A = Ba, Sr, Ca) photocatalytic materials were prepared using a solid-state method. The results show that changing the A-site doping element while keeping the B-site doping element constant leads to systematic variations in the band structure of KNbO3-based materials. The analysis reveals that as the ionic radius of the A-site dopant decreases, the conduction band and valence band of the samples exhibit an overall negative shift along the energy axis. The more negative conduction band energy level is favorable for electron reduction and hydrogen gas production. The hydrogen evolution rates of [KNbO3]0.98-[A(Ni1/2Sn1/2)O3]0.02(A = Ba, Sr, Ca) under simulated sunlight are 165.798 µmol/(g·h) (A = Ca), 151.697 µmol/(g·h) (A = Sr) and 119.487 µmol/(g·h) (A = Ba), respectively.