Er3+-activated Ba2V2O7 upconversion nanosheets for dual-mode temperature sensing.

So far, there has been substantial research on non-contact luminescence thermometry approaches that rely on luminescence intensity ratio (LIR) technology. However, there is limited availability of phosphors doped with Er3+ ions that exhibit on-par luminescence and high sensitivity. In this work, samples of Ba2V2O7:Er3+ were synthesized using a sol-gel method aided by citric acid. The luminescence properties of these samples, including upconversion and down-shifting, were investigated using both ultraviolet and 980 nm laser stimulation. When subjected to ultraviolet (UV) light, the sample exhibits a distinct broadband emission that appears pale green. This emission is a distinguishing property of the sample and is attributed to the presence of V2O72- ions. Upon being stimulated by a 980 nm laser, the sample exhibits standard green up-conversion Er3+ emission bands. Concurrently, an assessment was conducted on the phosphor's ability to measure temperature by analysing the LIR between the thermally coupled 2H11/2, 4S3/2 energy levels (TCELs) and the non-thermally coupled 2H11/2, 4F9/2 energy levels (NTCELs) of the Er3+ ion. The corresponding highest sensitivity of temperature for TCELs and NTCELs can position Ba2V2O7:Er3+ nanosheets as a capable option for materials utilized in temperature-sensing applications.

Upconversion Nanodevice-Assisted Healthy Molecular Photocorrection.

Mushrooms are rich in ergosterol, a precursor of ergocalciferol, which is a type of vitamin D2. The conversion of ergosterol to ergocalciferol takes place in the presence of UV radiation by the cleavage of the "B-ring" in the ergosterol. As the UV radiation cannot penetrate deep into the tissue, only minimal increase occurs in sunlight. In this study, upconversion nanoparticles with the property to convert deep-penetrating near-infrared radiation to UV radiation have been cast into a disk to use sunlight and emit UV radiation for vitamin D conversion. An engineered upconversion nanoparticle (UCNP) disk with maximum particles and limited clusters demonstrates ∼2.5 times enhanced vitamin D2 conversion.

Excitation dependent visible and NIR photoluminescence properties of Er3+, Yb3+ co-doped NaBi(MoO4)2 nanomaterials.

Due to the exceptional luminescence properties of lanthanide doped nanomaterials, they have applications in various field such as sensing, photocatalysis, solar cells, bio-imaging, therapy, diagnostics, anti-counterfeiting, latent fingerprint development, optical amplifiers, solid state lighting, etc. Here, we report the excitation dependent photoluminescence properties of Yb3+, Er3+ co-doped NaBi(MoO4)2 nanomaterials in both the visible and NIR regions upon UV, visible and NIR excitation. These photoluminescence properties show that strong energy transfer occurs from the host to the Yb3+, Er3+ ions. These materials show major emission bands at 530, 552 (green) and 656 nm (red) in the visible region and 1000 and 1534 nm in the NIR region. The intensity ratio between green and red bands is dependent on the excitation wavelength, whereas the intensity ratio of the 1000 and 1534 nm bands relies on the excitation wavelength and Er3+ doping concentration. These materials also exhibit host emission and upconversion luminescence properties in the visible region.

Synthesis of LaFeO3/Ag2CO3 Nanocomposites for Photocatalytic Degradation of Rhodamine B and p-Chlorophenol under Natural Sunlight.

Novel LaFeO3/Ag2CO3 nanocomposites are synthesized by co-precipitation method for photocatalytic degradation of Rhodamine B (RhB) and p-chlorophenol under visible light irradiation. Heterostructures between LaFeO3 and Ag2CO3 semiconductors are formed during the synthesis of these nanocomposites. Among the nanocomposites prepared with different ratios of LaFeO3 and Ag2CO3, 1% LaFeO3/Ag2CO3 shows the highest photocatalytic activity for the degradation of RhB. Maximum electron-hole pair decoupling efficiency is observed in 1% LaFeO3/Ag2CO3, which causes the greater activity of the heterostructure. Degradation efficiency of 99.5% for RhB and 59% for p-chlorophenol has been obtained under natural sunlight within 45 min. Interestingly, the stability of Ag2CO3 is improved dramatically after making nanocomposite, and no decomposition of the catalyst was observed even after several photocatalytic cycles. Reactive oxygen species scavenging experiments with p-benzoquinone, isopropyl alcohol, and ammonium oxalate suggest that a major degradation process is caused by holes. Degradation of RhB into small organic moieties is detected using LC-MS technique. Further, the efficient mineralization of the degradation products occurs during the catalytic process.

Liquid metal/metal oxide frameworks with incorporated Ga2O3 for photocatalysis.

Solvothermally synthesized Ga2O3 nanoparticles are incorporated into liquid metal/metal oxide (LM/MO) frameworks in order to form enhanced photocatalytic systems. The LM/MO frameworks, both with and without incorporated Ga2O3 nanoparticles, show photocatalytic activity due to a plasmonic effect where performance is related to the loading of Ga2O3 nanoparticles. Optimum photocatalytic efficiency is obtained with 1 wt % incorporation of Ga2O3 nanoparticles. This can be attributed to the sub-bandgap states of LM/MO frameworks, contributing to pseudo-ohmic contacts which reduce the free carrier injection barrier to Ga2O3.