Controlled Synthesis of Ce-Doped Y₂Si₂O₇ Clustered Materials with Improved High-Temperature Stability and Corrosion...

This study employed a sol-gel combined molten salt two-step method to synthesize cerium-doped yttrium disilicate (Ce-doped Y₂Si₂O₇, YCDS) cluster-like materials in a controlled manner, which were self-assembled from one-dimensional nanorods with high aspect ratios. These materials significantly enhance the high-temperature stability and corrosion resistance of silicate coating when used as multifunctional fillers. Ce doping induces oxygen vacancies (OVs) in the material, which serve as active sites preferentially absorbing oxygen molecules and capturing electrons, synergistically enhancing the corrosion resistance of the material. Ce(III) captures and consumes reactive oxygen species through oxidation reactions to form Ce(IV). Simultaneously, Ce(IV) is reduced back to Ce(III) with the assistance of OVs, enabling reversible conversion between oxidation states and conferring excellent antioxidant properties to the material. YCDS exhibits exceptional thermal stability, and its high aspect ratio cluster structure facilitates crack bridging and crack migration effects within the coating to dissipate fracture energy, effectively improving coating toughness and thermal shock resistance. After heat treatment at 1200 °C, YCDS exhibits only minimal mass loss. Coating incorporating it as a filler maintains structural integrity even in high-temperature oxidation environments up to 800 °C. After 72 h immersion in a 3.5 wt % NaCl solution, the total impedance value of the YCDS-coating reached 153.9% and 256.8% of those for the yttrium disilicate (YDS) system and traditional kaolin system, respectively. This study offers insights into the application of rare earth silicate materials for metal corrosion protection and the development of high-performance silicate protective coatings.