New rare earth hafnium oxynitride perovskites with photocatalytic activity in water oxidation and reduction
Ashley P. Black, Hajime Suzuki, Masanobu Higashi, Carlos Frontera, Clemens Ritter, Chandan De, A. Sundaresan, Ryu Abe* and Amparo Fuertes*. Chem. Commun., 2018,54, 1525-1528. DOI: 10.1039/C7CC08965A10.1039/C7CC08965A
RHfO2N perovskites with R = La, Nd and Sm show a GdFeO3-type structure and are semiconductors with band gaps of 3.35, 3.40 and 2.85 eV and relative dielectric constants of 30, 16 and 28 respectively. These compounds have adequate reduction and oxidation potentials to conduct the overall water splitting reaction, and the analogous perovskite LaZrO2N with a band gap of 2.8 eV shows photocatalytic activity under visible light irradiation for O2 evolution.