Tunable transition metal oxide/carbon aerogel catalysts: Insights into oxygen reduction and supercapacitor performance

Transition metal oxide (TMO)-based catalysts are crucial for various applications in which energy is stored and converted due to their unique properties and functionality. Herein, carbon aerogel (CA) with unique properties as a catalyst support material was first prepared. Then, six different transition metal oxide catalysts (CoO/CA, NiO/CA, MnO/CA, ZnO/CA, CuO/CA, Fe2O3/CA) were synthesized by the chemical co-precipitation method. The structural and morphological properties of these different TMO/CA catalysts are reported. Electrochemical studies of the synthesized catalysts revealed promising performance in both oxygen reduction catalysis and charge storage. Notably, MnO/CA demonstrated the most favorable results for oxygen reduction, achieving a diffusion-limited current density of −2.47 mA cm−2 at 1600 rpm with an electron transfer number of 3.4. Furthermore, MnO/CA exhibited excellent stability during chronoamperometric tests, showing high current density retention and no significant morphological or structural changes as confirmed by SEM and Raman analysis before and after the test. When evaluating charge-storage capabilities, ZnO/CA emerged as the top-performer, displaying a specific capacitance of 295 F g−1 at a current load of 1 A g−1. ZnO/CA also demonstrated remarkable stability, with its capacitance increasing with extended cycling. After 1000 cycles, the specific capacitance reached 132% of its initial value, highlighting its robust nature for energy storage applications.