CoPi/Co(OH)2 Modified Ta3N5 as New Photocatalyst for Photoelectrochemical Cathodic Protection of 304 Stainless Steel

In this work, CoPi and Co(OH)(2) nanoparticles were deposited on the surface of Ta3N5 nanorod-arrays to yield a novel broad-spectrum response photocatalytic material for 304 stainless steel photocatalytic cathodic protection. The Ta3N5 nanorod-arrays were prepared by vapor-phase hydrothermal (VPH) and nitriding processes and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-Vis spectroscopy, respectively, to obtain morphologies, crystal structures, surface compositions, and light response range. In order to analyze the performance improvement mechanism of CoPi/Co(OH)(2) on Ta3N5 nanorod-arrays, the electrochemical behavior of modified and unmodified Ta3N5 was obtained by measuring the open circuit potential and photocurrent in 3.5 wt% NaCl solution. The results revealed that the modified Ta3N5 material better protects 304 stainless steel at protection potentials reaching -0.45 V.