Synthesis of nanosized manganese methahydroxide stabilized by cystine

The paper presents a method for the synthesis of cystine-stabilized manganese metahydroxide nanoparticles. The resulting particles had a spherical shape, a diameter of the order of 16–25 nm, and were strongly agglomerated. Studies of the morphology, elemental and phase composition of MnO(OH) nanoparticles have been carried out. X-ray diffraction analysis revealed the presence of a semicrystalline MnO(OH) phase with an orthorhombic structure. A quantum-chemical simulation has been performed and models of the chemical bond formation between a cystine molecule and a fragment of the manganese metahydroxide unit cell were constructed. Based on the results of computer simulation, the most probable mechanism of MnO(OH) nanoparticles stabilization with cystine has been established. It lies in the interaction of the carboxyl group of cystine with the hydroxo group of manganese metahydroxide. •α-MnOOH nanoparticles have been synthesized by the chemical reduction method.•Cysteine can be both a reducing agent and a stabilizer for MnOOH NPs.•Simulation of the MnOOH NPs stabilization process has been performed.•When stabilized with cystine, MnOOH formed quasi-spherical NPs.