Formation of TiN-Ir particle films using pulsed-laser deposition and their electrolytic properties in producing hypochlorous acid

Using sintered TiN and TiN-Ir (Ir contents: 5.9-14.2 at.%) targets, pulsed-laser deposition (PLD) was carried out to produce thin films composed of nanoparticles and particulates in the presence of nitrogen gas. The size (2-100 nm) of the produced crystalline TiN nanoparticles increased as nitrogen pressure was increased in the range from 1.33 to 1.33 × 102 Pa. At a pressure of 1.33 × 103 Pa, amorphous TiN nanoparticles combined in the form of chains. Large Ir particulates with diameters of up to 2 μm were particularly prominent in TiN-Ir films. Size distributions of the Ir particulates were dependent on ablation laser wavelength; that is, the diameter decreased at laser wavelength shortened. The TiN-Ir films with different Ir contents and morphologies on Ti substrates were evaluated as electrolysis electrodes for water disinfection. The highest current efficiency was 0.45%, which is comparable to that of conventional Ti-Pt electrodes, for a chloride-ion concentration of 9 mg dm−3.