Manganese(III) oxide nanoparticles exhibit semiconductor behavior with notable redox activity and high surface area when engineered at the nanoscale, which enhances ion transport and active surface sites. These properties have been explored for energy storage applications, particularly as high-capacitance electrodes in supercapacitors and as cathode materials in emerging aqueous zinc-ion battery systems. Mn₂O₃ nanomaterials have also shown promising adsorption capabilities for organic dyes and potential photocatalytic and antibacterial activity under visible light.