Green synthesis of manganese dioxide (MnO2) nanoparticles produced with acerola (Malpighia emarginata) leaf extract

In this work, green synthesis of manganese dioxide nanoparticles was carried out using aqueous extract from acerola leaves (Malpighia emarginata), evaluating the effect of pH and concentration of the plant extract. The materials were characterized by XRD, nitrogen adsorption-desorption (BET), FTIR, TG/DTG, SEM and EDX, showing that the synthesis parameters had a statistically significant effect on the yield and particle diameter. The crystal phase was identified as alpha-MnO2, in addition to observations of high thermal stability and mesoporous structure with surface areas from 34.074 to 40.298 m2 g-1. The experimental design showed that the effect of pH on the particle size depended on the level of extract concentration used, as for 30 g L-1 an increase in pH decreased the diameter while with 60 g L-1 an opposite effect was observed.