Optical properties and surface composition of oxidized copper for solar absorbers

Manganese pigmented anodized copper as solar selective absorber

“…before any characterization. The aim of this post-treatment step is to stabilize the coating, using an additional oxidation electrolyte without chromium, contrary to previous work [11].…”

“…a value characteristic of a solar selective surface. So the post-treatment is efficient, inducing probably a stabilization of the coating chemistry through the CuO formation that usually increases the solar absorption by its low reflectance in the visible wavelength [11]. Figure 2 shows optical properties of the surface submitted to heat treatment in air during 5 and 10 days at The optical properties are also measured in vacuum during 10 days (Fig.…”

Low-cost black Cu–Ni alloy coatings for solar selective applications

“…Electroplating method is gaining importance over other method simply because of its commercial viability and practicability for large-scale production. A number of efforts have been made to electrodeposit black chromium [20][21][22][23][24][25], black nickel [26][27][28][29][30][31][32][33][34][35], black cobalt [36][37][38], black molybdenum [39][40][41][42][43], black copper coatings [44][45][46] and black aluminum [47][48][49][50][51]. Other known black coatings are Ni-Sn [52], Ni-Cd [53] Co-Sn [54], Co-Cd [55], Mo-Cu [56] and Fe-P [57].…”

Desenvolvimento de um secador solar indireto ativo.

“…Esse fenômeno ocorre quando dois metais com potenciais galvânicos muito diferentes estão em contato Um dos trabalhos pioneiros a utilizar esta dinâmica foi desenvolvido por Harding (1976), quando fizeram uma camada de óxido de cromo (Cr2O3) ser depositada por evaporação em substratos de cobre. Outros autores também obtiveram conclusões de resultados interessantes a partir da formação superficial dos demais óxidos metálicos sob a superfície do metal de base, óxido de ferro (Fe2O3) e óxido cuproso (Cu2O) (HORNSTROM et al, 1984;UMA et al, 1987).…”