Z-Scheme LaFeO3/Cd0.7Zn0.3S heterojunction based on 3DOM LaFeO3 perovskite for enhanced photocatalytic hydrogen activity

Abstract

The narrow band gap semiconductor LaFeO3 with ABO3 perovskite structure has been deeply studied in the field of photocatalysis due to its good thermal stability, chemical stability, photoelectric properties and suitable band position. The inverse opal structure gives the material a large specific surface area and increases the adsorption area and active site of the catalyst. In this work, it is reported for the first time that perovskite LaFeO3 inverse opal was applied to photocatalytic hydrogen production. The Cd0.7Zn0.3S QDs were deposited on the skeleton wall of LaFeO3 inverse opal to construct LaFeO3/Cd0.7Zn0.3S binary heterojunction catalyst. The LaFeO3 3DOM can effectively increase the contact area with Cd0.7Zn0.3S QDs with an increase in specific surface area, and the multiple scattering effect improves the efficiency of light utilization. The introduction of Zn2+ ions regulate the band gap position of Cd0.7Zn0.3S QDs and increases the thermodynamic reduction ability of photo generated electrons. The Z-type heterojunction effect formed by LaFeO3 inverse opal and Cd0.7Zn0.3S QDs facilitates the separation and transmission of photo generated charges. The LaFeO3/Cd0.7Zn0.3S heterojunction catalysts achieved a hydrogen production performance of 277.48 μmol/g/h due to the large specific surface area of 3DOM, good light capture ability, band gap regulation of element doping, and efficient charge separation synergistic effect of heterojunction. This work provides new insights into the design and manufacture of perovskite-type 3DOM heterojunction photocatalysts.