Characterization of wet processed (Ni, Zn)-ferrites for Co₂ decomposition

Ultrafine (Ni, Zn)-ferrites were prepared by two different methods of coprecipitation and hydrothermal synthesis, and their oxygen-deficient ferrites (ODF) produced by hydrogen reduction were investigated on the efficiency of CO₂ decomposition. The crystalline sizes of (Ni, Zn)-ferrites were less than 30 nm with high Brunauer-Emmett-Teller (BET) surface areas, ranging from 77 to 172 m² g^-1. The (Ni, Zn)-ferrites by hydrothermal synthesis resulted in smaller crystalline sizes, higher BET surface areas and better efficiencies of CO₂ decomposition than by coprecipitation. Compared with the binary NiFe₂O_4-δ ferrite, the ternary (Ni_x, Zn_1-x) Fe₂O_4-δ ferrites showed higher efficiency for CO₂ decomposition, indicating a potential catalyst for the reduction of CO₂ emission in the environmental atmosphere.