Thermal co-decomposition of silver acetylacetonate and tin(II) hexafluoroacetylacetonate: Formation of carbonaceous Ag/AgxSn(x = 4 and 6.7)/SnO2 composites

Highlights: • Ag acetylacetonate increases thermal stability by mixing with Sn hexafluoroacetylacetonate. • Heated mixture of chelates yields a residue containing Ag, Sn, O and C elements. • Residues obtained at higher temperature contain Ag–Sn intermetallic compounds. - Abstract: Thermal co-decomposition of silver(I) acetylacetonate and tin(II) hexafluoroacetylacetonate has been examined by using thermal gravimetry, differential scanning calorimetry and complementary analyses of gaseous products and solid residues by Fourier transform infrared and Raman spectroscopy, X-ray diffraction and scanning electron microscopy. It is revealed that poorly stable silver(I) acetylacetonate mixed with tin(II) hexafluoroacetylacetonate does not undergo thermal decomposition at around 120 °C, but takes part in a room-temperature solid-state interaction with the Sn counterpart, which is ensued by an exothermal process at 109 °C and subsequent co-decomposition involving a pronounced stage at around 275 °C. All steps lead to carbonaceous Ag/SnO2 composites containing crystalline Ag at 200 °C, Ag and SnO2 at 400 °C, and Ag, SnO2, Ag4Sn and Ag6.7Sn at 600 °C. The intermetallic Ag6.7Sn compound is judged to arise from nanostructured environment of alloying Ag and Sn