Ultra-Small One-Dimensional Rice-Like comoo4 Nanorods as a Promising Pseudocapacitive Electrode for High-Performance Supercapacitors

The demand for sustainable energy sources increases as society progresses. Supercapacitors possess a long lifespan, have a high power density, are ecologically sound, and have the ability to rapidly charge and discharge. Among the several binary transition metal oxides (BTMOs), metal molybdates (AMoO<inf>4</inf>) are notable for their significant redox activity, widespread availability, affordability, and small ecological footprint. The exceptional theoretical capacitance of CoMoO<inf>4</inf>, resulting from the presence of active cobalt ions, distinguishes it from other materials. However, the synthesis of CoMoO<inf>4</inf> in nanostructured forms presents a challenge. This study introduces a straightforward one-pot solvothermal technique for producing ultra-small, one-dimensional (1D) rice-like CoMoO<inf>4</inf> nanorods. The electrochemical performance of rice-like CoMoO<inf>4</inf> nanorods as a supercapacitor electrode material was thoroughly investigated, along with larger CoMoO<inf>4</inf> nanorods made using the hydrothermal process for comparison. The structural, morphological, and surface characteristics of the rice-like CoMoO<inf>4</inf> nanorods were comprehensively examined. The nanorods, formed like rice grains, exhibited exceptional ability to store electric charge, with an outstanding specific capacitance of 1608.8 F g−1. They demonstrated remarkable cycling stability, retaining 96 % of their capacitance after numerous charge and discharge cycles, indicating their durability and reliability. The nanorods also exhibited a high rate capability of 71 %, which is crucial for applications that demand quick energy delivery. This capability enables the nanorods to maintain considerable capacitance even at higher charge-discharge rates. The results indicate that rice-like CoMoO<inf>4</inf> nanorods can be used as a material in supercapacitors. © 2024 Elsevier Ltd