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Luminescent metal‐organic frameworks (LMOFs) are promising materials for nanophotonic applications due to their tuneable structure and programmability. Yet, the 3D nature of LMOFs creates challenges for stability, optical transparency, and device integration. Metal‐organic nanosheets (MONs) potentially overcome these limitations by combining the benefits of metal‐organic frameworks (MOFs) with an atomically thin morphology of large planar dimensions. Herein, the bottom‐up synthesis of few‐layer thin ZIF‐7‐III MONs via facile low‐energy salt‐templating is reported. Employing guest@MOF design, the fluorophores Rhodamine B and Fluorescein are intercalated into ZIF‐7 nanosheets (Z7‐NS) to form light emissive systems exhibiting intense and highly photostable fluorescence. Aggregation and Förster resonance energy transfer, enabled by the MON framework, are revealed as the mechanisms behind fluorescence. By varying guest concentration, these mechanisms provide predictable quantified control over emission chromaticity of a dual‐guest Z7‐NS material and the definition of an "emission chromaticity fingerprint" – a unique subset of the visible spectrum that a material can emit by fluorescence. [ABSTRACT FROM AUTHOR]

Broadband light detection and sensing are widely applied in modern technology. As a promising candidate for next-generation two-dimensional (2D) optoelectronic material, bismuth oxyselenide (Bi2O2Se) nanoplates exhibit many prospects in the application of visible light detection due to their peculiar properties. In this work, we report the photodetection performance of single-crystal 2D Bi2O2Se nanoplates grown on SiO2 based on a ternary-alloy growth model by utilizing chemical vapor deposition (CVD). The Bi2O2Se nanoplates were found to have an even and uniform square shape with side lengths up to 15 µm and an approximate thickness of 15 nm. A visible-light photodetector was fabricated based on a CVD-grown Bi2O2Se nanoplate, and characterized by a set of illumination experiments using a 400 nm laser at temperatures ranging from 77 to 370 K. The device exhibited superior performance at the temperature of 77 K, with a responsivity of 523 A/W, a specific detectivity of 1.37 × 1011 Jones, a response time of 0.2175 ms, and an external quantum efficiency of 162,119.44%, resulting in high-quality and full-color imaging in the visible spectrum. These results indicate that the single-crystalline Bi2O2Se nanoplates have excellent potential in broadband photodetection and non-cryogenic imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Z-scheme BaFe 2 O 4 /BiOCl nanocomposite was synthesized. • The synthesized nanocomposite showed superior POME treatment under visible light. • The nanocomposite can be magnetically separated and reused. • Z-scheme e − transfer accelerated charge separation and granted high redox ability. • Enhanced bactericidal activities towards E. coli and B. cereus were observed. In recent years, organic pollution and biological hazards have become indisputable considerable environmental issues. Semiconductor-based photocatalysis has been regarded as a promising and sustainable solution in minimizing the negative impacts of these issues. Herein, a two-step precipitation-hydrothermal method was employed to fabricate novel Z-scheme BaFe 2 O 4 /BiOCl nanocomposites as efficient visible light-driven photocatalysts. The physicochemical properties and morphological characteristics of the fabricated nanocomposites were investigated via multiple characterization methods. The BiOCl nanosheets loaded with 5 wt% BaFe 2 O 4 particles (5 wt% BaFe 2 O 4 /BiOCl) demonstrated the best visible light photoactivity with a palm oil mill effluent (POME) degradation efficiency of 61 % and a reaction rate constant of 0.0045 min−1 within 210 min. The photocatalytic enhancement benefited from the formation of Z-scheme heterojunction between BaFe 2 O 4 and BiOCl, hence accelerating the interfacial charge transfer and maintaining strong redox potential for active radical generation. Moreover, by regulating the pH value of photoreaction system, more superior POME degradation efficiency was attained and reached 85 % at the same duration. Interestingly, the 5 wt% BaFe 2 O 4 /BiOCl nanocomposite also possessed a convenient catalyst separation along with good recyclability with only 7 % loss in efficiency after four successive runs. Based on the active species scavenging experiment, superoxide radical was found as the eminent active species during the POME treatment. In addition to the investigation of POME treatment, the fabricated 5 wt% BaFe 2 O 4 /BiOCl nanocomposite was also successfully employed to inactivate the E. coli and B. cereus. This study revealed that the as-fabricated BaFe 2 O 4 /BiOCl nanocomposite had great potential applications to degrade various organics and to inactivate bacteria from wastewater. [ABSTRACT FROM AUTHOR]

Abstract: Eosin Y, a well‐known economical alternative to metal catalysts in visible‐light‐driven single‐electron transfer‐based organic transformations, can behave as an effective direct hydrogen‐atom transfer catalyst for C−H activation. Using the alkylation of C−H bonds with electron‐deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y‐based photocatalytic hydrogen‐atom transfer strategy is promising for diverse functionalization of a wide range of native C−H bonds in a green and sustainable manner. [ABSTRACT FROM AUTHOR]

Abstract: Synchronous front‐face fluorescence and visible spectroscopies are utilized for the simple, rapid, and nondestructive quantification of extra virgin olive oil (EVOO) adulteration with corn, soybean, and sunflower oils. For each adulterant, 42 adulterated EVOO samples in the adulterant amount in the range 1.0–50 g/100 g were prepared. The partial‐least‐squares regression was executed for quantification. Both full (leave‐one‐out) cross‐validation and external validation were performed to evaluate the predictive ability. The plots of observed vs. predicted values exhibit high linearity. The coefficient of determination (R2) values are larger than 0.99. The root mean square errors of both cross‐validation and prediction are no more than 2%. The detection limits for the three seed oils using fluorescence and visible spectroscopies are in the range of 1.5–2.2% and 1.8–2.4%, respectively. The merit of this method is that both the front‐face fluorescence and visible spectroscopies are recorded toward neat oils, avoiding any sample pretreatment including dilution. [ABSTRACT FROM AUTHOR]

We report an application of data fusion for chemometric classification of 135 canned samples of Chinese lager beers by manufacturer based on the combination of fluorescence, UV and visible spectroscopies. Right-angle synchronous fluorescence spectra (SFS) at three wavelength difference Δ λ = 30, 60 and 80 nm and visible spectra in the range 380–700 nm of undiluted beers were recorded. UV spectra in the range 240–400 nm of diluted beers were measured. A classification model was built using principal component analysis (PCA) and linear discriminant analysis (LDA). LDA with cross-validation showed that the data fusion could achieve 78.5–86.7% correct classification (sensitivity), while those rates using individual spectroscopies ranged from 42.2% to 70.4%. The results demonstrated that the fluorescence, UV and visible spectroscopies complemented each other, yielding higher synergic effect. [ABSTRACT FROM AUTHOR]

A TEMPO-oxidized straw cellulose-doped yttrium oxide (Y 2 O 3 -SC) was obtained via a hydrothermal method in the present work. The Y 2 O 3 -based materials were fully characterized. Plate count method was used to investigate the antibacterial activity of the Y 2 O 3 -SC composite. Antibacterial tests showed that Y 2 O 3 and its nanocomposites exhibited good antibacterial activities toward both Gram-negative Escherichia coli ( E. coli ) and Gram-positive Staphylococcus aureus ( S. aureus ). Besides, visible light irradiation could improve antibacterial activity of the Y 2 O 3 -SC. Antibacterial mechanism was also presented based on the results of scavengers experiment. Considering the excellent antibacterial activity of Y 2 O 3 -SC, the silver nanoparticle free nanocomposite is a promising candidate for cleaning the microbial contamination. [ABSTRACT FROM AUTHOR]