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Lanthanide ions doped luminescent materials are widely studied for latent fingerprint detection. However, most of these materials are synthesized at very high temperatures and use UV C light for visualization, which is harmful to eye, skin, etc. Herein, the Gd0.95Eu0.05PO4 nanorods synthesized by a simple co-precipitation method at 185 °C were reported for latent fingerprint visualization under 395 nm light. The Gd0.95Eu0.05PO4 nanomaterial has monoclinic crystal structure and shows rod-shaped morphology. Further, these Gd0.95Eu0.05PO4 nanorods exhibit excellent photoluminescence properties and strong fuchsia emission under UV light. These nanorods have been employed for developing latent fingerprints on various porous and non-porous substrates by the powder dusting technique, which exhibits clear and well defined details with high contrast, selectivity and sensitivity under 395 nm UV light. Latent fingerprints developed after 72 h of their deposition also show clear contrast with these nanorods. Therefore, the Gd0.95Eu0.05PO4 nanorods can be used for latent fingerprint visualization applications.

The PVDF/Ag2CO3nanocomposite film has demonstrated the various potential applications as a mechanical energy harvester, acoustic sensor, and piezocatalytic properties.

High surface area MnO2 nanomaterials were synthesized by a simple selective cation dissolution method. These nanostructures are highly active for photochemical as well as electrochemical water oxidation.

Water oxidation is an energy-consuming, four-electron-transfer reaction and is essential for solar fuel production from water. Catalysts based on precious metals such as RuO2 and IrO2 show high eff...

Studies on lanthanide ions doped upconversion nanomaterials are increasing exponentially due to their widespread applications in various fields such as diagnosis, therapy, bio-imaging, anti-counterfeiting, photocatalysis, solar cells and sensors, etc. Here, we are reporting upconversion luminescence properties of NaBi(MoO4)2:Ln3+, Yb3+ (Ln = Er, Ho) nanomaterials synthesized at room temperature by simple co-precipitation method. Diffraction and spectroscopic studies revealed that these nanomaterials are effectively doped with Ln3+ ions in the scheelite lattice. DR UV–vis spectra of these materials exhibit two broad bands in the range of 200–350 nm correspond to MoO42− charge transfer, s-p transition of Bi3+ ions and sharp peaks due to f-f transition of Ln3+ ions. Upconversion luminescence properties of these nanomaterials are investigated under 980 nm excitation. Doping concentration of Er3+ and Yb3+ ions is optimized to obtain best upconversion photoluminescence in NaBi(MoO4)2 nanomaterials and is found to be 5, 10 mol % for Er3+, Yb3+, respectively. NaBi(MoO4)2 nanomaterials co-doped with Er3+, Yb3+ exhibit strong green upconversion luminescence, whereas Ho3+, Yb3+ co-doped materials show strong red emission. Power dependent photoluminescence studies demonstrate that emission intensity increases with increasing pump power. Fluorescence intensity ratio (FIR) and population redistribution ability (PRA) of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 transitions of Er3+ increases with increasing the Yb3+ concentration. Also, these values increase linearly with increasing the pump power up to 2 W. It reveal that these thermally coupled energy levels are effectively redistributed in co-doped samples due to local heating caused by Yb3+.

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.

Bismuth based host materials for doping rare earth ions gained considerable interest due to the possibility of forming crystalline homogeneous solid solution phases over a wide range and their excellent luminescent properties. In the present manuscript, a facile synthesis method for preparation of nanocrystalline NaBi(MoO4)2 and their optical properties are presented. The influence of various synthetic parameters such as precursor concentration, reaction time and reaction temperature on phase formation have been investigated and revealed that these nanoparticles can be synthesized even at 5 °C within 5 min with a Bi/Mo ratio of 1:4. All the doped and undoped samples show scheelite type tetragonal structure. Formation of solid solution between NaBi(MoO4)2 and NaEu(MoO4)2 over the complete range of compositions could be achieved. A systematic decrease in the unit cell parameters is observed with increasing concentration of Eu3+ ion in NaBi1–xEux(MoO4)2. Investigations on the luminescence properties of europ...

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.

A Rh-catalyzed domino synthesis of 4-hydroxy-3-methylcoumarins via branch-selective hydroacylation of acrylates and acrylamides using salicylaldehydes is described. This protocol under phosphine-free Rh-catalyzed conditions provided 4-hydroxy-3-methylcoumarins in high yields with excellent functional group tolerance and high selectivity.

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.

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

Novel Rh-catalyzed aldehydic C–H bond alkynylation and annulation for the in situ synthesis of chromones and aurones are described. It involves the sequential aldehyde C–H bond alkynylation of salicylaldehyde with in situ generated 1-bromoalkyne from 1,1-dibromoalkene followed by annulation. This protocol shows good functional group tolerance including aryl, alkenyl, alkyl and heteroaryl-1,1-dibromoalkenes. The steric/electronic effect was demonstrated during the base-mediated in situ cyclization of o-hydroxyynones to generate aurones.

In the present study, influence of In3+ doping on the structural and luminescence properties of ZnGa2O4 nanoparticles has been investigated in detail. In3+ doped ZnGa2O4 nanoparticles with size less than 10 nm have been prepared at a relatively low temperature of 120 °C. From X-ray diffraction (XRD) and photoluminescence (PL) studies, different Ga3+ structural units, with varying number of In3+ as next nearest neighbors (NNN) around Ga3+ in GaO6 octahedra, have been identified and their relative extent is evaluated by assuming a binomial distribution of Ga3+ and In3+ cations in the lattice. The GaO6 octahedra are found to be unaffected by In3+ doping as confirmed by the identical values of oxygen positional parameter “x” derived from Rietveld refinement of the XRD patterns. Alternating current powder electroluminescence (ACPEL) has been demonstrated for the first time from the nanoparticles of undoped and In3+ doped ZnGa2O4. Due to the formation of GaO6 structural units with varying number of In3+ as next near neighbors around Ga3+, tuning of emission wavelength is observed from the nanoparticles upon UV excitation. However, under an applied electric field during electroluminescence (EL) measurements, only regular GaO6 structural units undergo excitation and Ga-O-In linkages mainly act as scattering centers leading to less favorable electrical excitation of corresponding GaO6 structural units. The findings have potential relevance in the area of wide band gap semiconductor technology employing doped ZnGa2O4 nanoparticles.