The fabrication and luminescent performance of novel phosphors Na₂YMg₂V₃O₁₂:Dy³⁺ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na₂YMg₂V₃O₁₂ host self-activated and released a broad emission band (400–700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO₄)³⁻ groups. Meanwhile, the Na₂YMg₂V₃O₁₂:Dy³⁺ phosphors emitted bright yellow light within both the broad emission band of the (VO₄)^3- groups and the sharp peaks of the Dy³⁺ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na₂YMg₂V₃O₁₂:Dy³⁺ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y₂O₃:Eu³⁺ red phosphors, and BaMgAl₁₀O₁₇:Eu²⁺ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na₂YMg₂V₃O₁₂:Dy³⁺ phosphor as a yellow-emitting phosphor in solid-state illumination.

Personal thermal management materials integrated with phase-change materials have significant potential to satisfy human thermal comfort needs and save energy through the efficient storage and utilization of thermal energy. However, conventional organic phase-change materials in a solid state suffer from rigidity, low thermal conductivity, and leakage, making their application challenging. In this work, polyethylene glycol (PEG) was chosen as the phase-change material to provide the energy storage density, polyethylene oxide (PEO) was chosen to provide the backbone structure of the three-dimensional polymer network and cross-linked with the PEG to provide flexibility, and carbon nanotubes (CNTs) were used to improve the mechanical and thermal conductivity of the material. The thermal conductivity of the composite fiber membranes was boosted by 77.1% when CNTs were added at 4 wt%. Water-resistant modification of the composite fiber membranes was successfully performed using glutaraldehyde-saturated steam. The resulting composite fiber membranes had a reasonable range of phase transition temperatures, and the CC₄PCF-55 membranes had melting and freezing latent heats of 66.71 J/g and 64.74 J/g, respectively. The results of this study prove that the green CC₄PCF-55 composite fiber membranes have excellent flexibility, with good thermal energy storage capacity and thermal conductivity and, therefore, high potential in the field of flexible wearable thermal management textiles.