Promotion of fluorescence and temperature sensitive properties for 8YSZ:Eu3+ thermo-sensitive ceramic powders by nitrogen-modified Ti3C2Tx MXene

Abstract

Fluorescence temperature measurement technology offers a promising approach for real-time monitoring of internal temperature in thermal barrier coatings (TBCs). However, under high-temperature and corrosion environments of TBCs, luminescent materials experience substantial challenges, including reduced fluorescence intensity, shortened decay lifetime and diminished temperature sensitivity. In this paper, nitrogen modified Ti3C2Tx MXene (N-MXene, Tx represents -O, -OH, -F, and -N functional groups) was prepared and mechanically grounded with Eu-doped 8 mol% yttria-stabilized zirconia (8YSZ:Eu3+, Zr0.92Y0.08O1.96: Eu3+) ceramic materials to produce N-MXene/8YSZ:Eu3+ composites, enhancing the fluorescence and temperature sensitive properties of Eu3+. Results showed that homogenous N-MXene/8YSZ:Eu3+ composites with uniformly distributed Zr, Y, O, Eu, Ti, C, F and N elements were successfully synthetized. The 8YSZ:Eu3+ ceramic particles, with an average particle size of about 18 nm, were embedded within the porous, wrinkled structure of N-MXene. The addition of N-MXene did not alter the symmetry or electron transitions of Eu3+ but significantly improved luminescence intensity, fluorescence lifetime and temperature sensitivity of 8YSZ:Eu3+ powders. The optimal fluorescence characteristics were observed in composites containing 0.6 wt% N-MXene. The emission intensities for 5D0→7D1 and 5D0→7D2 transition were up to 7 times higher than those of pure 8YSZ:Eu3+ powders at room temperature and nearly 6 times higher at 500 K. The fluorescence lifetime of 8YSZ:Eu3+ powders were extended from 1.41 to 1.50 ms by N-MXene. The absolute and relative sensitivity of Y/NM-6 thermo-sensitive ceramic powders were SA (Y/NM-6) = 3.32 % K−1@350K, SR (Y/NM-6) = 0.32 % K−1@350K respectively, compared to SA (8YSZ:Eu3+) = 0.49 % K−1@350K, SR (8YSZ:Eu3+) = 0.16 % K−1@350K for 8YSZ:Eu3+. These findings demonstrate the N-MXene/8YSZ:Eu3+ composition is a potential thermos-sensitive ceramic with excellent fluorescence properties for monitoring service temperature in TBCs.