Synthesis and evaluation of corrosion resistance of molybdate-based conversion coatings on electroplated zinc

Core shell like behavior of PdMo nanoparticles on multiwall carbon nanotubes and their methanol oxidation activity in alkaline medium

“…Surprisingly when the pH of the precursor solutions is increased to pHw5 and pHw7 the Mo peak at 232.78 disappears and the 2nd peak (Mo 3d 3/2 ) shifted to about 237 eV which is the evidence of typical chemical shift of Mo (IV) compounds [39] and can be expected due to MoO 2 or MoO 4 2À like species [40]. When pH of the precursor solution reaches w9, Mo peaks disappeared.…”

Sebacic acid as corrosion inhibitor for hot‐dip galvanized (HDG) steel in 0.1 M NaCl

“…Inorganic compounds are commonly used to promote the formation of a conversion layer of hardly soluble compounds on the galvanized steel surface. Among them, conversion coatings based on molybdates (MoO 4 2− ), tungstates (WO 4 2− ), lanthanides (Ce, La), silicates (Na 2 SiO 3 , K 2 SiO 3 ), trivalent chromium (Cr (III)), titanium and zirconium (Ti, Zr), n‐ tetradecanephosponic acids, and phosphates (PO 4 3− ) have been tested on zinc substrate.…”

Electrochemical analysis of molybdate conversion coating on hot‐dip galvanized steel in various growth stages

“…It is now generally accepted that chromate solution, although a good corrosion inhibitor, will eventually be phased out from manufacturing processes . There is therefore an intense research effort being undertaken to replace chromates with more environmentally friendly, non‐toxic or less toxic inhibitors or passivators, such as phosphate, molybdate, silicate, rare earth salts, and organic compounds …”

“…Among these potential alternatives, molybdate conversion layers were proposed as a potential replacement for chromate coatings, thanks to the low toxicity of molybdate ions and the possibility of forming conversion coatings on metallic surfaces like chromate ones. Also, molybdate is an environmentally acceptable and effective corrosion inhibitor for zinc, galvanized steel, and other metals . Additionally, it was reported that the addition of sodium hydrogen phosphate to the sodium molybdate solution resulted in the formation of phosphomolybdic heteropoly acid, which was a strong oxidant, and reacted with metallic matrix to form a molybdate coating .…”