Tailoring the size and electrochemical performance of Mn3O4 nanoparticles by controlling the precipitation process

Abstract Mn 3 O 4 nanoparticles were prepared at 60 °C in ethanol solution by a facile precipitation method. It was found that the particle size of the as-prepared Mn 3 O 4 depended on the alkalinity of precipitants. Nanoparticles with average size of 6 nm were obtained by using morpholine as precipitant which had low alkalinity, while 10 nm particles were produced by using NaOH as precipitant. The former particles presented higher degree electrochemical double-layer capacitor-like behavior and higher electrochemical performance than the latter. This could be attributed to the effective faradaic reactions of particles, which originated from the low equivalent series resistance resulting from their smaller particle size. Graphical Abstract Mn 3 O 4 nanoparticles were prepared in ethanol by a facile precipitation method using precipitants with different alkalinity. It was found that smaller particles (a) were generated by using precipitant with low alkalinity as compared with the one with higher alkalinity (b). As a result, the Mn 3 O 4 nanoparticles presented a high-degree electrochemical double-layer capacitor-like behavior due to their low equivalent series resistance.