In this study, a trimetallic nanocomposite comprising Silver Copper–Nickel (Ag–Cu–Ni TNC) was synthesized and analysed for its efficiency in degrading benzene and benzopyrene, which has five fused ...benzene rings. Fabrication of trimetallic nanocomposites were characterized using UV spectroscopy, FTIR studies, SEM EDAX, and DLS results. XRD confirmed the cubic crystalline Fcc structure of Ag–Cu–Ni TNC. Photocatalytic degradation analysis revealed that Ag–Cu–Ni TNC has the efficient photocatalytic ability, and the optimum condition required for efficient degradation of benzene and benzopyrene was identified as 2 μg/mL of PAH molecule, 10 μg/mL of Ag–Cu–Ni TNC at pH 5, stirring time of 2 h placed under UV light. Based on these optimum conditions, kinetic and isotherm studies were performed, revealing that the adsorption of benzene and benzopyrene by Ag–Cu–Ni TNC fits well with the Pseudo-second order kinetic model and Freundlich isotherm model. Thus, our study's adsorption of PAH molecule from aqueous solution takes place through chemisorption and involves heterogeneous adsorption phenomena.
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•Fabrication of trimetallic Ag–Cu–Ni nanocomposite and characterization of fabricated.•Characterization studies confirmed the fabrication of Ag–Cu–Ni TNC with an average crystalline size ranging from 105 nm to 592 nm.•The optimum condition required for adsorption of benzene and benzopyrene.•The adsorption mechanism fitted well with the Pseudo-second order kinetic and Freundlich isotherm model.
Even though steadily increasing, biofluorescence is a rarely documented phenomenon in vertebrates. Within geckos, only six species have been shown to produce fluorescence and only one case of dermal ...fluorescence has been reported. Here, we report on the discovery of dermal fluorescence in the Dune Sand Gecko (Stenodactylus doriae), the Eastern Sand Gecko (S. leptocosymbotes), and the Arabian Web-footed Sand Gecko (Trigonodactylus arabicus), three closely-related, nocturnal, desert-adapted Arabian geckos. We show that there are interspecific differences in fluorescent regions which might be linked to the habitat preference and behaviour of each species. Our results are in agreement with prior hypotheses suggesting that desert-adapted geckos might use dermal biofluorescence for conspecific signalling. With the present work, we expand the current knowledge on skin fluorescence in reptiles and provide new insights on fluorescence of desert-adapted geckos.
•Second case of dermal fluorescence in geckos.•Species inhabiting sand dune deserts show wider and brighter fluorescent regions.•Fluorescence might be biologically relevant for conspecific signaling in these desert-dweller geckos.•The closest case of dermal fluorescence is from another desert-dweller species which diverged from Stenodactylus and Trigonodactylus geckos more than 70 mya.
Although human eyes are quite insensitive to ultraviolet (UV) light, most of the longer wavelength UV light (the UV‐A band between 320 and 400 nm) does reach the earth surface and after prolonged ...exposure, the radiation can cause health concerns especially skin cancer. Therefore, it is extremely important to explore ways to effectively monitor the radiation. Herein we report for the first time a new high‐performance UV photodetector made of an individual Nb2O5 nanobelt. Quasi‐aligned Nb2O5 nanobelts 100–500 nm wide and 2–10 μm long were synthesized using a hydrothermal treatment of a niobium foil in a KOH solution followed by proton exchange and calcination treatment. A nanostructured photodetector was constructed from an individual Nb2O5 nanobelt and its optoelectronic properties were evaluated. The detector exhibited linear photocurrent characteristics, excellent light selectivity, and high external quantum‐efficiency (EQE) of 6070%. Long‐term stability of the photocurrent over a period of 2500 s at an applied voltage of 1.0 V was achieved. The photodetector performance was further enhanced by improving the crystallinity and eliminating the defects in the Nb2O5 nanobelt crystals. These excellent optoelectronic properties demonstrate that Nb2O5 nanobelts are suitable for visible‐blind UV‐light sensors and optoelectronic circuits, especially those operating in the UV‐A range.
A new and high‐performance ultraviolet photodetector was successfully constructed from an individual Nb2O5 nanobelt for the first time. The as‐constructed photodetector exhibited a high photosensitivity, light selectivity, excellent photocurrent stability, and high external quantum efficiency (6070%), demonstrating that Nb2O5 nanobelts is a perfect candidate for visible‐blind ultraviolet‐light sensors, especially for working in the UV‐A band.
Construction of heterojunction between semiconductors is considered an effective strategy for enhancing photocatalytic capability. Herein, this work prepared an abundant porous g-C3N4/TiO2 ...photocatalyst, with the two-dimensional (2D) nanosheet g-C3N4 and nanoparticle TiO2. The heterojunction both enhanced the ultraviolet (UV) light absorption ability, and inhibited the recombination of photogenerated electron-hole (h+) pairs. As expected, the optimal 4 % g-C3N4/TiO2 (g-C3N4:TiO2 = 1:25) exhibited a prominent degradation efficiency of 96.53 % in the photocatalytic performance of tetracycline hydrochloride (TCH) under UV irradiation. The recycling of the heterojunction photocatalyst g-C3N4/TiO2 remained stability and reusability. The main active species were·O2-, h+ and·OH, and the formation of internal electric field on the step-scheme (S-scheme) heterojunction interface accelerated the migration of photogenerated carriers. Moreover, several environmental factors on degradation such as dose, pH, and the initial concentration of TCH were investigated. This work could be spread to the conceive of other S-scheme heterojunction photocatalysts in application to different environmental demands.
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•The internal electric field on g-C3N4/TiO2 interface benefits charges migration.•The tetracycline can be efficaciously removed by g-C3N4/TiO2 heterojunction.•Step-scheme g-C3N4/TiO2 heterojunction is prospective in tetracycline wastewater purification.
In the present study, describes the synthesis of ZnO nanoparticles from rambutan (Nephelium lappaceumL.) peel extract via bio synthesis method and developed a new low cost technology to prepare ZnO ...nanoparticles. During the synthesis, fruit peel extract act as a natural ligation agent. The successfully prepared product was analyzed with some standard characterization studies like X-Ray Diffraction (XRD), UV-VIS Diffuse reflectance spectra (UV–Vis DRS), Field Emission Scanning Electron Microscope (FESEM), High resolution transmittance electron microscope (HR-TEM), N2 adsorption-desorption isotherm and UV–Vis absorption Spectroscopy. The photocatalytic activity of ZnO nanoparticles was evaluated by photodegradation of methyl orange (MO) dye under UV light and the result depicts around 83.99% decolorisation efficiency at 120 min of illumination. In addition with photodecolorisation, mineralization was also achieved. The mineralization has been confirmed by measuring Chemical Oxygen Demand (COD) values.
•Bio-synthesis method is a simple and efficient route for the development of low cost ZnO nanoparticles.•Plant extracts could be an alternative to chemical reagents.•Plant extracts plays the dual role of a fuel with a coordinating action.•Bio-synthesized ZnO nanoparticles showed small particle size and high surface area.
•Cerium oxide assists the preparation of high-quality perovskite film.•Cerium oxide layer facilitates interface charge transfer and absorb UV light.•The modified devices have the enhanced ...performance, especially UV light stability.
Ultraviolet (UV) illumination can induce the generation of defects at the interface of perovskite and commonly used electron transport materials (ETMs, such as TiO2 and SnO2) in perovskite solar cells (PSCs). This further increase the interfacial charge recombination and accelerate the decomposition of perovskite film, resulting in the attenuation of device efficiency and stability. Here, a cerium oxide (CeOx) nanoparticle with an average size of 18.66 nm is proposed as a novel mesoporous material to modify the interface of ETM and perovskite. The CeOx mesoporous layer with higher electron mobility and more suitable band energy level facilitates charge transfer from perovskite layer. As expected, the mesoporous CeOx based PSCs exhibits an improved power conversion efficiency up to 23.15% (22.57% for control device). More importantly, the mesoporous CeOx layer (about 70 nm) can realize the effective absorption of UV light, to efficiently improve the UV light stability of PSCs and the overall stability of the devices. The unencapsulated devices with mesoporous CeOx maintained almost 90% of initial efficiency after 850 h under UV illumination. This work provides a new approach to fabricate the efficient and UV stable PSCs by introducing the mesoporous CeOx layer.
A cost-effective, automated and portable IC has been developed for in-situ analysis of nitrite and nitrate in natural waters. The system employed 3D printed pumps for eluent delivery and a deep-UV ...LED based optical detector. Isocratic separation and selective detection of nitrite and nitrate was achieved in under 3 min. The total weight of the analyser was ~11 kg, and included electronics along with a sample intake system for automated analysis. Linear calibration ranges were generated using different sample injection loops. Using a 150 μL loop, an analytical range (0.05–30 mg L−1 NO2−, 0.10–75 mg L−1 NO3−) suitable for freshwater analysis was generated, while using a 10 μL loop an analytical range (0.30–100 mg L−1 NO2−, 2.5–500 mg L−1 NO3−) suitable for effluent and domestic wastewater analysis was achieved. Chromatographic repeatability demonstrated by the system is graphically presented and RSD values of <4% were obtained in terms of peak area and retention time over 82 sequential runs. The system was deployed in-situ at multiple sites for varying deployment periods analysing septic tank water, effluent from a waste water treatment plant and stream water. The data generated by the in-situ system were comparable to grab sample data generated by accredited laboratory instrumentation.
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•Fully automated, portable ion chromatography system for water quality monitoring.•Rapid, selective detection of nitrite and nitrate using UV-LED based detector.•Ion chromatography system deployed to analyse range of environmental waters.•Comparable analytical performance compared to accredited instrumentation.
