Features of zinc passivation by sodium dodecylphosphontate in a neutral aqueous solution

•Sodium dodecylphosphonate (С12PNa2) is chemosorbed on zinc surface and forms passive films that increase zinc durability.•The adsorption activity of С12PNa2 is the most pronounced on an oxide-free zinc surface.•The possibility of adsorption passivation of zinc with С12PNa2 has been shown.•The protective layer formed in a С12PNa2 solution on zinc consists of the [С12PZn] complex (P:Zn = 1:1), ZnO and Zn(OH)2.•The composition of phosphonate layers depends on the initial state of zinc surface and determines their protective ability. The features of the adsorption and passivating effect of sodium dodecylphosphonate (C12PNa2) on zinc, as well as the effect of electrode potential and presence of a surface oxide on them were studied. The possibility of zinc adsorption passivation by C12PNa2 with formation of nanolayers that inhibit zinc corrosion in a chloride-containing neutral solution and in a humid atmosphere was shown. The adsorption properties of C12PNa2 are most pronounced on an oxide-free zinc surface. The composition of the layers formed by C12PNa2 depends on the initial state of the surface and determines their protective ability.