Development and Characterization of Photocatalytic GaN Coatings by Cold Spray Process

For the first time, low-pressure cold spray (LPCS) process was used to manufacture gallium nitride (GaN) films enhance its photocatalytic properties and decrease manufacturing cost. The deposition behavior of GaN powder on stainless steel substrates investigated. Several specimens, with sparsely deposited agglomerated particles, were prepared under different conditions. Quantitative analysis evolution coverage area, particle count, average sectional area shows that, upon impact, particles disintegrate, leading large small particles. By analyzing cross-sectional particle, no discernible permanent deformation substrate observed. In addition, x-ray diffraction coatings indicated that phase transformation occurred during process. Based Williamson–Hall analysis, broader peaks mainly attributed distortions in lattice rather than changes crystallite size. At 400°C 0.6 MPa, efficiency reached 5.3%, activities coating about 33% (+9% compared powder). It is higher specific surface roughness exhibit after breakage spray.