Corrosion of sodium tungsten bronze nanoparticles in high-humidity environments

• DOI: 10.1016/j.ceramint.2024.02.089
• Publication Date: 2024-02-07T09:07:19Z
• Authors: Levi Tegg; Joel Fernandes; Julie M. Cairney
• Keywords: Bronze; Tungsten trioxide

Sodium tungsten bronzes (NaxWO3) are reduced metal oxides with applications in nanoparticle plasmonics. Despite decades of research, little is known about the conditions under which they can corrode. Here, NaxWO3 nanoparticles were exposed to high-humidity air for 71 days induce corrosion. The samples studied ex-situ by using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. low-Na sample (x = 0.4) corroded slowly into a single, insulating, hydrated Na–W–O–N phase over 10 weeks. high-Na 0.7) fully after only 4 weeks, decomposing at least 3 corrosion products, including observed sample. complex process, rate both was reasonably well-described first-order equation, allowing straightforward estimation kinetics. Although phases could not be unambiguously determined, EDS XRD data suggests that hydrated, sodiated tungstates appear contain N. These findings help clarify corrode important designing use bronze nanoparticles.