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Yttrium orthovanadate (YVO4) powders were synthesized by two different routes: the combustion route (C sample), and the hydrothermal route (H samples). In all samples, oxygen vacancies were observed by Raman, UV–vis diffuse reflectance and photoluminescence (PL) spectroscopy; however they were more significant in C sample. Photocatalytic discoloration of Rhodamine B solutions ranged from 40 to 64% and C and H4 samples presented the highest efficiencies. Although both samples showed similar photocatalytic efficiency, C sample is 11 times more efficient in producing reactive oxygen species than H4 sample, and an interesting effect of the treated solutions was observed in the Fish Embryotoxicity Test, carried out in D. rerio. The C-treated solution was more toxic than the untreated solution, while the H4-treated solution did not show toxicity enhancement. C-treated solution caused a significant mortality of D. rerioembryos beginning at the 4th day of exposure and reached total mortality at the 6th day. Thus, the synthetic route employed in the preparation of C and H4 samples leads to different toxic effects in the treated solutions. These results pointed out that microstructural characteristics and synthetic parameters are not only important for obtaining highly active materials, but they also impact on the toxicity of the effluents.

Analysis of gunshot residues (GSR) is a vital point of interest in forensic chemistry. GSR analysis is very well established, but there is still a lack of methodology to identify GSR obtained from lead-free or ‘non-toxic ammunition’ (NTA). To identify GSR from NTA, we have proposed the incorporation of luminescent markers to provide an optical and chemical signature to GSR. Furthermore, the luminescent markers can open up prospectives for ammunition encoding by adjusting their composition. Herein, we report the distinction among GSR particles containing different MOF-based markers by analyzing their organic fractions using near-infrared hyperspectral imaging (NIR-HSI) together with multivariate analysis (MCR-ALS). The method has been proven to be effective, non-destructive and fast in distinguishing marked GSR. It is possible to detect and correctly identify 72.2% of the samples, and all cases of misclassification are related to slight amount of material collected (8.3%) or confusion caused by one of the markers (19.4%). The study is developed in a forensic context of GSR analysis; however, the methodology described here is excellent and can be extrapolated to other applications that require distinguishing MOFs with different ligands.

A multifunctional smart supramolecular platform based on a lanthanide-organic hydrogel is presented. This platform, which provides unique biocompatibility and tunable optical properties, is synthesized by a simple, fast, and reproducible eco-friendly microwave-assisted route. Photoluminescent properties enable the production of coated light-emitting diodes (LED), unique luminescent barcodes dependent on the excitation wavelength and thin-films for use in tamper seals. Moreover, piroxicam entrapped in hydrogel acts as a transdermal drug release device efficient in inhibiting edemas as compared to a commercial reference.

The presence of organic pollutants in the environment, especially in water, is recognized as a continuing threat to environmental stability. Therefore, the development of new materials for the removal of organic pollutants in water are of fundamental importance. In this paper, a heterojunction SrSnO3/g-C3N4photocatalytic system was synthesized and its photocatalytical performance for Rhodamine-B (RhB) degradation has been tested. For this purpose, in situluminescence measurements were carried out for the first time here, for monitoring the photodegradation process in real time under real reaction conditions performance. The degradation profiles of RhB using the SrSnO3/g-C3N4composite and pure g-C3N4showed that the degradation of the dye occurs through different mechanisms including four processes: N-de-ethylation, chromophore cleavage, opening-ring and mineralization. The results demonstrate that the SrSnO3/g-C3N4ratio 1:1 (SSO3) and 1:2 (SSO4) provide high photocatalytic activity under solar light. Best results were observed for composite SSO3, which displayed TOC removal of 97.3 ± 0.03 % after 4 h of solar exposure, while SSO4 and pure g-C3N4obtained a rate of 72.4 ± 0.03 % and 44.6 ± 0.04 %, respectively. Result of in situexperiments showed that composite SSO3 was 1.7 times more efficient in the RhB degradation than pure g-C3N4. The toxicity of phototreated solution was evaluated by Fish Embryo Test (FET) showing the successful photodegradation of RhB to non-toxic species.