Preparation and characterization of blue-light-excited nanophosphors using an economically low-energy process

The role of 2-ethylhexanoic acid in manipulating the morphology and upconversion of flame-made Y2O3:Yb3+/Ho3+ nanoparticles towards remote temperature sensing

“…4 presents the FTIR spectra of the Y 2 O 3 :Yb 3+ (8 mol%)/Ho 3+ (1 mol%) UCNPs with different 2-EHA/RE 3+ molar ratios ( x /1, x = 0, 0.5, 1, 1.5, 2, 2.5, 3), which were normalized according to the Y–O vibration absorption peak at ∼560 cm −1 . 24–28 Intense bands around ∼3420 cm −1 have been observed and are assigned to the stretching vibrational frequency of O–H. 24–28 The characteristic peak at ∼1385 cm −1 is due to the vibration absorption of NO 3 − .…”

“…24–28 Intense bands around ∼3420 cm −1 have been observed and are assigned to the stretching vibrational frequency of O–H. 24–28 The characteristic peak at ∼1385 cm −1 is due to the vibration absorption of NO 3 − . 24–28 When the 2-EHA/RE 3+ ratio is 0/1, the peak of NO 3 − is sharp and intense, indicating the presence of more NO 3 − groups on the surface of particles, and further manifesting the bad evaporation of nitrate in the precursor, which supports the previous explanation of particle growth routes.…”

“…24–28 The characteristic peak at ∼1385 cm −1 is due to the vibration absorption of NO 3 − . 24–28 When the 2-EHA/RE 3+ ratio is 0/1, the peak of NO 3 − is sharp and intense, indicating the presence of more NO 3 − groups on the surface of particles, and further manifesting the bad evaporation of nitrate in the precursor, which supports the previous explanation of particle growth routes. As the 2-EHA/RE 3+ ratio increases, the peak of NO 3 − persists but is not as sharp as before, and the increasing content of 2-EHA will lead to the emergence of the vibration absorption of carbonyl (CO) at ∼1530 cm −1 .…”

“…4 presents the FTIR spectra of the Y 2 O 3 : Yb 3+ (8 mol%)/Ho 3+ (1 mol%) UCNPs with different 2-EHA/ RE 3+ molar ratios (x/1, x = 0, 0.5, 1, 1.5, 2, 2.5, 3), which were normalized according to the Y-O vibration absorption peak at ∼560 cm −1 . [24][25][26][27][28] Intense bands around ∼3420 cm −1 have been observed and are assigned to the stretching vibrational frequency of O-H. [24][25][26][27][28] The characteristic peak at ∼1385 cm −1 is due to the vibration absorption of NO 3 − . [24][25][26][27][28] When the 2-EHA/RE 3+ ratio is 0/1, the peak of NO 3 − is sharp and intense, indicating the presence of more NO 3 − groups on the surface of particles, and further manifesting the bad evaporation of nitrate in the precursor, which supports the previous explanation of particle growth routes.…”

“…As the 2-EHA/ RE 3+ ratio increases, the peak of NO 3 − persists but is not as sharp as before, and the increasing content of 2-EHA will lead to the emergence of the vibration absorption of carbonyl (CO) at ∼1530 cm −1 . 28,29 The gradually intensifying vibration absorption of CO will increase the phonon energy of the particles, which may be sufficient to quench the intensities of the UCL bands.…”