Electrospinning preparation and high near-infrared temperature sensing performance of one-dimensional Y2Ti2O7:Cr3+/Yb3+ nano wire-embedded-tube structures with low Cr3+ concentrations

Abstract

One-dimensional Y₂Ti₂O₇:Cr³⁺/Yb³⁺ nano wire-embedded-tube structures composed of an outer nanotube with an outside diameter of 180–200 nm and a wall thickness of 30–36 nm and embedded wire with a diameter of 32–36 nm were fabricated via a simple single-nozzle electrospinning method at an air humidity of 45%. The Cr³⁺ content in the one-dimensional Y₂Ti₂O₇:Cr³⁺/Yb³⁺ nanostructures is very low and accounts for approximately 0.5% of the total moles of Yb³⁺, Y³⁺, and Cr³⁺ ions. The energy transfer mechanism from Cr³⁺ to Yb³⁺ is systematically studied. The near-infrared luminescent properties of the one-dimensional Y₂Ti₂O₇:Cr³⁺/Yb³⁺ nano wire-embedded-tube structures, especially the temperature sensing performance, were investigated. The one-dimensional Y₂Ti₂O₇:Cr³⁺/Yb³⁺ nano wire-embedded-tube structures have emissions of 650–1100 nm and excellent temperature sensing properties. The maximum absolute sensitivity (S_a) and high relative sensitivity (S_r) values are 6.01–8.73%K⁻¹ and 3.93–4.71%K⁻¹, respectively, which are much higher than those of the previous Cr³⁺ and Cr³⁺/RE³⁺ co-doped near-infrared phosphors and other up-conversion phosphors doped by RE³⁺ ions.