The 41st volume of the Journal of Metastable and Nanocrystalline Materials presents articles that analyse distinct melting models of aluminium, silver, gold and lead nanoparticles and the photocatalytic (dye degradation) activity of green synthesised paramagnetic nanoparticles for the water purification process, synthesis method of nanocomposite coating for corrosion protection, preparation of silver-graphene oxide nanocomposite for antibacterial applications and manganese-doped copper sulphide nanoparticles for thin film application. The presented publication will be helpful to many specialists in applied materials science and nanotechnologies.