Surfactant-assisted hydrothermal synthesis of ultrafine CoMoO4·0.9H2O nanorods towards high-performance supercapacitors

Abstract

In this study, one-dimensional (1D) CoMoO₄·0.9H₂O nanorods (NRs) with different sizes and crystallinities were controllably fabricated via a facile hydrothermal strategy coupled with the assistance of various surfactants, and further utilized as electroactive materials for supercapacitors. The significant influences of surfactants on the crystalline phases, sizes and electrochemical performance of the resulting CoMoO₄·0.9H₂O were systematically investigated. Physicochemical characterization demonstrated that the 1D NR product (denoted as CMO-CTMAB) synthesized by using hexadecyl trimethyl ammonium bromide (CTMAB) was endowed with the weakest crystallization, minimum size (∼10 nm) and the highest specific surface area (∼98 m² g⁻¹), when compared to other anionic and/or non-ionic surfactants. Benefiting from their weak crystallization, large electroactive surface, and 1D nanoscale architecture, the ultrafine CMO-CTMAB NRs manifested excellent electrochemical capacitance with the largest specific capacitance (SC) of 377 F g⁻¹ and high SC retention (∼93%) in 2 M KOH up to 1000 cycles at a current rate of 0.5 A g⁻¹.