Catalytic performance of TiVCTx@La0.4Ca0.6Co0.6Fe0.4O3 composites toward the oxygen evolution and oxygen reduction reactions

Abstract

Developing a highly efficient and low-cost bifunctional oxygen electrode catalytic material is of vital importance for the development of energy conversion and storage devices. Perovskite-type oxides (ABO₃) have been widely studied as one of the new candidate catalysts for oxygen electrodes due to their excellent catalytic performance. In this study, we synthesized MXene TiVCTₓ and perovskite oxide La_0.4Ca_0.6Co_0.6Fe_0.4O₃, and combined the two materials at different mass ratios to prepare catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The oxygen electrode catalyzed by 10% TiVCT_x (TiVCT_x accounts for 10% of the total mass of the composite catalyst) exhibited excellent stability under steady-state galvanostatic conditions. In the polarization test, the catalytic oxygen electrode displayed the highest current densities of 0.3889 A·cm^− 2 (1.0 V vs. Hg/HgO) in anode mode and 0.2712 A·cm^− 2 (-0.6 V vs. Hg/HgO) in cathode mode. The charge transfer resistance of the electrode catalyzed by 10% TiVCT_x was lower than that of La_0.4Ca_0.6Co_0.6Fe_0.4O₃ and TiVCT_x. The results showed that the optimal mass ratio of TiVCTₓ to La_0.4Ca_0.6Co_0.6Fe_0.4O₃ maximized the synergistic effect, yielding the best catalytic activity for oxygen evolution and oxygen reduction reactions. This provides reliable material design ideas and experimental evidence for building efficient, stable and low-cost bifunctional oxygen electrodes.