White LED Light Research Articles

Development of an operational trap for collection, killing, and preservation of triatomines (Hemiptera: Reduviidae): the kissing bug kill trap.

Surveillance of triatomines or kissing bugs (Hemiptera: Reduviidae: Triatominae), the insect vectors of Trypanosoma cruzi, a Chagas disease agent, is hindered by the lack of an effective trap. To develop a kissing bug trap, we made iterative improvements over 3 years on a basic design resulting in 7 trap prototypes deployed across field sites in Texas, United States and Northern Mexico, yielding the capture of 325 triatomines of 4 species (Triatoma gerstaeckeri [Stål], T. sanguisuga [LeConte], T. neotomae [Neiva], and T. rubida [Uhler]). We began in 2019 with vertical transparent tarpaulin panel traps illuminated with artificial light powered by AC current, which were successful in autonomous trapping of flying triatomines, but were expensive, labor-intensive, and fragile. In 2020, we switched to white LED lights powered by a solar cell. We tested a scaled-down version of the vertical panel traps, a commercial cross-vane trap, and a multiple-funnel trap. The multiple-funnel traps captured 2.6× more kissing bugs per trap-day than cross-vane traps and approached the performance of the vertical panel traps in number of triatomines captured, number of triatomines per trap-day and triatomines per arthropod bycatch. Multiple-funnel traps required the least labor, were more durable, and had the highest triatomines per day per cost. Propylene glycol in the collection cups effectively preserved captured triatomines allowing for molecular detection of T. cruzi. The trapping experiments established dispersal patterns for the captured species. We conclude that multiple-funnel traps with solar-powered LED lights should be considered for adoption as surveillance and potentially mass-trapping management tools for triatomines.

Simple synthesis of AgInS2/ZnS core/shell quantum dots with wide tunable emission wavelength for white light-emitting diodes

Phosphor with efficient and broad range emission is necessary for lighting applications. I-III-VI group quantum dots (QDs) have the advantages of non-toxic composition and large adjustable spectrum range, and have potential applications in the field of lighting. However, the efficient luminescence of these QDs at shorter wavelengths still needs further study, which is crucial for the development of high color rendering index white light LED devices (WLEDs). In this work, wide visible range emitting AgInS2/ZnS QDs with broad band and high luminous efficiency were obtained by altering the Ag/In ratios and Zn2+ inter-diffusion with cation of AgInS2. Photo-luminescent (PL) wavelength range of the obtained core-shell structured AgInS2/ZnS extended from 703 nm to 524 nm with high PL quantum yield (QY) and stability. The champion device based on the optimized AgInS2/ZnS QDs exhibits warm white light (correlated color temperature = 3652 K) characteristics with high color rendering index (CRI Ra) of 92.85 while maintaining excellent color stability under different driving currents. These properties are far superior to those of WLEDs with YAG phosphor.

Rational design of ZnO/SrTiO3 S-scheme heterojunction for photo-enhanced piezocatalytic hydrogen production

Photopiezocatalysis have been frequently investigated for hydrogen evolution reactions in recent years. Herein, ZnO, SrTiO3 and ZnO/SrTiO3 S-scheme heterojunction were investigated for photo/piezocatalytic hydrogen production. Piezocatalytic hydrogen production under ultrasonic vibration by using ZnO, SrTiO3 and ZnO/SrTiO3 was obtained as 270 µmol g-1h−1, 200 µmol g-1h−1 and 1265 µmol g-1h−1, respectively. In addition, ZnO/SrTiO3 S-scheme heterojunction showed 2200 µmol g-1h−1 photopiezocatalytic hydrogen production under simultaneous exposure to white LED light and ultrasonic sound. ZnO/SrTiO3 heterojunction displayed significantly higher hydrogen production rate due to the decreased charge recombination, increased charge transfer with strong piezoelectric polarization and internal electrical field. The piezoelectric effect of ZnO/SrTiO3 heterojunction is also confirmed by piezoresponse force microscope technique with butterfly and phase hysteresis loops. Also, piezoelectric coefficient of ZnO/SrTiO3 found about 2-folds higher than those of their pristine forms. Electron transfer and reaction mechanism of ZnO/SrTiO3 and activity differences are confirmed by advanced optical and electrochemical techniques such as diffuse reflectance spectroscopy, electronic impedance spectroscopy, Mott-Schottky calculation and chronoamperometry. The whole electrochemical measurements have been performed with or without mechanical stress and light irradiation, which signify their band bending properties, electron transfer mechanism and catalytic activities.

Physicochemical, optical and magnetic properties of ZrO2/Fe2O3 nanocomposite and its application in photocatalysis and antibacterial treatment

In this work ZrO2/Fe2O3 nanocomposite was synthesised through hydrothermal method using an innovative approach. X-ray diffraction (XRD) analysis revealed the formation of tetragonal ZrO2 and α-Fe2O3 in the nanocomposite. The FTIR spectra of the prepared samples exhibited characteristic peaks corresponding to ZrO2 and Fe2O3 and UV–Visible spectroscopy reveals that the nanocomposite exhibits a significantly lesser bandgap than the pure nanoparticles as determined by the Kubelka Munk function used for bandgap computation. Photoluminescence analysis substantiates the reduction in the recombination rate in the ZrO2/Fe2O3 nanocomposite as compared to the pure ZrO2 nanoparticles. Reduction in the bandgap as well as the recombination rate makes the nanocomposite favourable in the photocatalytic treatment of organic pollutants. Raman analysis was carried out to study the vibrational characteristics of the samples. Further, the prepared nanocomposite was examined for its applicability in photocatalysis, by analysing its degradation ability on Eosin yellow and Eosin Blue dyes under white light LED irradiation. The composite exhibited significant degradation ability than the pure nanoparticles, which makes it an ideal candidate for the treatment of organic pollutants. The nanocomposite exhibited ferromagnetic behaviour as confirmed through Vibrating sample Magnetometry, so it can be easily retrieved after the treatment. The prepared ZrO2/Fe2O3 nanocomposite was tested for its antibacterial efficacy against two Gram positive bacteria (Enterococcus faecalis, Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa). From the antibacterial studies it was validated that the nanocomposite exhibited significant antibacterial efficiencies against the bacteria. Hence the prepared nanocomposite has been proved to be a potential candidate for the treatment of organic pollutants as well as for antibacterial treatment.

Evaluation of Bioactive Compounds and Antioxidant Activity of Green and Red Kale (Brassica oleracea L. var. acephala) Microgreens Grown Under White, Red, and Blue LED Combinations

Microgreens have great potential for improving the nutritional value of human diets, as well as constituting a promising dietary option for preventing chronic disease. Light-emitting diodes (LEDs) are commercially used as a light source to improve the growth of microgreens, as well as nutrient and bioactive compound accumulation. Here, we provide the first report of the phenolic compound, chlorophyll and carotenoid pigment, and dietary fiber contents of red and green kale microgreens grown in a growth chamber under white LEDs combined with red or blue light. Significant differences in the response of phytocompounds between white light and its combination with blue or red LEDs were determined. These studies showed that a combination of white and blue LEDs positively influenced the accumulation of phenolic compounds, which consequently determined high antioxidant activity. On the contrary, the white LED lights were the most suitable for the accumulation of carotenoids and chlorophylls, including chlorophyll a and b, and Klason lignin. These results suggest that the use of a combination of white light with blue or red light can increase the concentration of phenolic compounds and dietary fiber in red and green kale microgreens and thus may enhance their health-promoting potential.

Imaging pollen using a Raspberry Pi and LED with deep learning

The production of low-cost, small footprint imaging sensor would be invaluable for airborne global monitoring of pollen, which could allow for mitigation of hay fever symptoms. We demonstrate the use of a white light LED (light emitting diode) to illuminate pollen grains and capture their scattering pattern using a Raspberry Pi camera. The scattering patterns are transformed into 20× microscope magnification equivalent images using deep learning. We show the ability to produce images of pollen from plant species previously unseen by the neural network in training. Such a technique could be applied to imaging airborne particulates that contribute to air pollution, and could be used in the field of environmental science, health science and agriculture.

A Novel Broadband Green Phosphor La2W2O9: Bi3+, and Its Application in High Color-Rendering Index pc-WLED

Broadband green phosphors have important applications in overcoming the blue-green (cyan) 470–510[Formula: see text]nm gap of phosphor-converted white LED (pc-WLED) and achieving high color rendering index (CRI) white lighting. In this work, a broadband green phosphor La2W2O9: [Formula: see text]Bi[Formula: see text] was synthesized by solid-state method. The phase, morphology and luminescence properties of the series of phosphors were systematically studied. The results showed the La2W2O9: [Formula: see text]Bi[Formula: see text] green phosphor exhibits a wide emission band in the range of 400–800[Formula: see text]nm with full width at half-maximum (FWHM) of 164[Formula: see text]nm, filling the cyan gap and reaching its peak at 550[Formula: see text]nm. The phosphor exhibits broadband excitation, and the excitation range covers the wavelength region of 200–500[Formula: see text]nm, and matches well with commercial ultraviolet LED. With the obtained broadband green phosphor, commercial CaAlSiN3:Eu[Formula: see text] red phosphor, commercial BaMgAl[Formula: see text]O17:Eu[Formula: see text] blue phosphor, and a 365[Formula: see text]nm commercial chip, a warm white pc-WLED device with a high color-rendering index (Ra[Formula: see text]97.4, R1–R15[Formula: see text]90) and low correlated color temperature (CCT[Formula: see text]3610[Formula: see text]K) was fabricated. The results demonstrate the wide range of applications for La2W2O9:Bi[Formula: see text] phosphor in the field of premium warm white LED lighting.

Highly Efficient Wide Bandgap Perovskite Solar Cells With Tunneling Junction by Self-Assembled 2D Dielectric Layer.

Reducing non-radiative recombination and addressing band alignment mismatches at interfaces remain major challenges in achieving high-performance wide-bandgap perovskite solar cells. This study proposes the self-organization of a thin two-dimensional (2D) perovskite BA2PbBr4 layer beneath a wide-bandgap three-dimensional (3D) perovskite Cs0.17FA0.83Pb(I0.6Br0.4)3, forming a 2D/3D bilayer structure on a tin oxide (SnO2) layer. This process is driven by interactions between the oxygen vacancies on the SnO2 surface and hydrogen atoms of the n-butylammonium cation, aiding the self-assembly of the BA2PbBr4 2D layer. The 2D perovskite acts as a tunneling layer between SnO2 and the 3D perovskite, neutralizing the energy level mismatch and reducing non-radiative recombination. This results in high power conversion efficiencies of 21.54% and 19.16% for wide-bandgap perovskite solar cells with bandgaps of 1.7 and 1.8 eV, with open-circuit voltages over 1.3 V under 1-Sun illumination. Furthermore, an impressive efficiency of over 43% is achieved under indoor conditions, specifically under 200 lux white light-emitting diode light, yielding an output voltage exceeding 1 V. The device also demonstrates enhanced stability, lasting up to 1,200 hours.

Investigation of luminescence properties and energy transfer mechanism in Sm3+ and Eu3+ co-doped BaY2ZnO5 red phosphors

In this investigation, the photoluminescence properties, energy transfer phenomenon of BaY2ZnO5:Sm3+/Eu3+ doped/co-doped phosphor are reported and synthesized by high temperature solid state reaction method. The crystal structure, micromorphology, optical diffuse reflectance and photoluminescence properties of the samples were studied. The results show that concentration quenching phenomenon is found. With the increase of Eu3+ ion concentration, the emission peaks of Sm3+ gradually decrease, indicating that energy transfer between Sm3+ and Eu3+. The optimal concentrations are 0.05 mol and 0.2 mol for single doping Sm3+ and Eu3+, respectively. The energy transfer efficiency is calculated to be 78.47–95.19 %. The BaY2ZnO5 phosphors have potential application value in the fields of white light LEDs and anti-counterfeiting.

Novel synthesis organic–inorganic heterojunctions of protonated g-C3N4/Fe3O4/AgBr/AgCl/AgI quinary magnetic photocatalyst with enhanced visible-light photocatalytic degradation of methylene blue in water

A novel magnetic quinary nanocomposite, protonated g-C3N4/Fe3O4/AgBr/AgCl/AgI, was synthesized using a wet chemical method. The multi-heterojunction photocatalyst with multi-carrier source and multi-channel carrier transport is constructed to enhance the photocatalytic degradation performance of pure g-C3N4. The design of the quinary nanocomposite is also an effective approach to solve the chemical stability problem of silver halides. The photocatalytic degradation efficiency under visible light irradiation was analyzed for methylene blue (MB) as the target organic pollutant. The quinary nanocomposite with 10 % g-C3N4 displayed high photocatalytic performance, with 83 % of MB degraded under 6 h LED white light irradiation. The effective quinary nanocomposite has good magnetic properties and can be magnetically separated to prevent secondary pollution of the photocatalyst in water. Parameters such as initial concentration of pollutant, initial solution pH, and light source were studied. Zeta potential results showed that the quinary nanocomposite could disperse homogenously to decrease aggregation in the solution. The photocatalytic degradation mechanism was investigated, and the mineralization results were analyzed based on liquid chromatography-mass spectroscopy (LC-MS) and total organic carbon (TOC). It was found that the hydroxyl and superoxide radicals were major reactive species by scavenging experiments. Additionally, protonated g-C3N4/Fe3O4/AgBr/AgCl/AgI nanocomposite showed excellent reusability after magnetic separation and regeneration, thus suggesting it to be a promising photocatalyst for treating wastewater containing organic contaminants.

Integrated transcriptomic and miRNA-seq analysis of Pak-choi provides insight into the molecular mechanisms involved in the preservation of postharvest quality by white LED light irradiation

Low-intensity white light-emitting diode (LED) irradiation effectively delays postharvest senescence in pak-choi at 20 °C and 90 % relative humidity. In this study, RNA-seq and miRNA-seq analyses were conducted on samples collected at 0 d (initial sample) and 5 d (CK and LED-treated samples) to evaluate the regulatory effects of white LED irradiation on miRNA. The resulting data revealed a total of 23 differentially expressed miRNAs (DEmiRNAs) in the CK/LED group on 5 d of storage. LED irradiation induced the expression of AP2 family genes and the biosynthesis of aliphatic glucosinolates by modulating the level of bra-miR172 family miRNAs. LED irradiation also stimulated the expression of genes associated with the photosynthetic pathway in pak-choi and regulated biosynthesis of ascorbic acid and resistance-associated transcription factors by modulating the level of novel miRNAs. Furthermore, LED irradiation suppressed cellulase and polygalacturonase activity, and maintained the pectin content. These findings demonstrate the ability of white LED light irradiation to significantly delay the postharvest senescence process in pak-choi by modulating miRNA expression.

Research on CdSe/ZnS Quantum Dots-Doped Polymer Fibers and Their Gain Characteristics.

Polymer fibers are considered ideal transmission media for all-optical networks, but their high intrinsic loss significantly limits their practical use. Quantum dot-doped polymer fiber amplifiers are emerging as a promising solution to this issue and are becoming a significant focus of research in both academia and industry. Based on the properties of CdSe/ZnS quantum dots and PMMA material, this study experimentally explores three fabrication methods for CdSe/ZnS quantum dots-doped PMMA fibers: hollow fiber filling, melt-drawing, and melt extrusion. The advantages and disadvantages of each method and key issues in fiber fabrication are analyzed. Utilizing the CdSe/ZnS quantum dots-doped PMMA fibers that were fabricated, we theoretically analyzed the key factors affecting gain performance, including fiber length, quantum dots doping concentration, and signal light intensity. Under the conditions of 1.5 W power and 445 nm laser pumping, a maximum on-off gain of 16.2 dB was experimentally achieved at 635 nm. Additionally, using a white light LED as the signal source, a broadband on-off gain with a bandwidth exceeding 70 nm and a maximum gain of 12.4 dB was observed in the 580-650 nm range. This research will contribute to the development of quantum dots-doped fiber devices and broadband optical communication technology, providing more efficient solutions for future optical communication networks.

Cytotoxic and pro-oxidant profile of a photosensitive ruthenium nitrosyl candidate for NO delivery in healthy human fibroblasts.

Ruthenium nitrosyl (Ru-NO) complexes are of interest as photoactive nitric oxide (NO) donor candidates for local therapeutic applications. NO plays a crucial regulatory role in skin homeostasis, concentration-dependently affecting processes like the proliferation, apoptosis, autophagy and redox balance. In this context, we investigated HE-10, a ruthenium-based photoinducible NO donor, for its pro-oxidant and cytotoxic effects under light and dark conditions in VH10 human foreskin fibroblast cells. We also tested its intracellular and extracellular NO-releasing function. Our study reveals a significant dose-dependent cytotoxic effect of HE-10, an increase in intracellular reactive oxygen and nitrogen species, and the occurrence of apoptosis in skin fibroblast cells. Furthermore, exposure to both increasing doses of HE-10 and white LED light led to substantial cellular events, including a significant induction of autophagy and G2/M phase cell cycle arrest. Paradoxically, these effects were not solely attributable to NO release based on DAF2-DA NO probe results, suggesting that intracellular photochemical reactions additional to NO photolysis contribute to HE-10's biological activity. This study shows that HE-10 exhibits both cytotoxic and potential therapeutic effects, depending on concentration and light exposure. These findings are crucial for developing targeted Ru-NO complex treatments for skin diseases and potentially certain types of skin cancer, where controlled NO release could be beneficial.

Unified Crystal Phase Control with MACl for Inducing Single-Crystal-Like Perovskite Thin Films in High-Pressure Fusion Toward High Efficiency Perovskite Solar Cell Modules.

Perovskite solar cells, recognized for their high photovoltaic conversion efficiency (PCE), cost-effectiveness, and simple fabrication, face challenges in PCE improvement due to structural defects in polycrystalline films. This study introduces a novel fabrication method for perovskite films using methylammonium chloride (MACl) to align grain orientation uniformly, followed by a high-pressure process to merge these grains into a texture resembling single-crystal perovskite. Employing advanced visual fluorescence microscopy, charge dynamics in these films are analyzed, uncovering the significant impact of grain boundaries on photo-generated charge transport within perovskite crystals. A key discovery is that optimal charge transport efficiency and speed occur in grain centers when the grain size exceeds 10µm, challenging the traditional view that efficiency peaks when grain size surpasses film thickness to form a monolayer. Additionally, the presence of large-sized grains enhances ion activation energy, reducing ion migration under light and improving resistance to photo-induced degradation. In application, a perovskite solar cell module with large grains achieve a PCE of 22.45%, maintaining performance with no significant degradation under continuous white LED light at 100 mA cm-2 for over 1000h. This study offers a new approach to perovskite film fabrication and insights into optimizing perovskite solar cell modules.

Evaluating CO2 concentration effects on growth kinetics and fatty acid composition in Euglena gracilis

ABSTRACT Industrial development has significantly increased CO2 emissions, from 280 ppm in the pre-industrial era to over 400 ppm today, contributing to the greenhouse effect and climate change. This study investigates the impact of varying CO2 concentrations on the growth, biomass accumulation, and biochemical composition of Euglena gracilis as microalgae-based carbon capture and utilization. E. gracilis was cultivated with CO2 concentrations of 0%, 5%, 10%, and 30%, using white LED lights at 3000 lux. Growth was monitored through cell counts and optical density, while biomass and primary metabolites were analysed using standard methods. Fatty acid content was assessed using GC-MS and GC-FID. The results showed optimal growth at 5% CO2, with biomass reaching 2.3 g l‒1 on the day of harvest. The highest lipid content was obtained in the 15% CO2 treatment with a total lipid of 0.35 g l‒1. As for the decrease in pH, it showed that each treatment experienced a reduction in pH from 3.5 to almost 2.0. Fatty acid content was dominated by polyunsaturated fatty acids (PUFAs), especially in the control group and 15% CO2 treatment, contributing up to 47.66%, and 46.36% to the group, respectively. The study highlights the importance of optimizing CO2 levels for microalgae cultivation to enhance biomass and lipid production. Elevated CO2 levels boost lipid synthesis but can stress cells if too high, suggesting a need for adaptive CO2 addition methods.

Vacuum-Deposited Bifacial Perovskite Solar Cells.

Bifacial perovskite solar cells (Bi-PSCs) require thick perovskite layers to sufficiently absorb higher wavelength light. Also, it is critical to know which electrode (top or bottom) can more efficiently harvest the direct incident solar irradiance. Here, fully vacuum-deposited Bi-PSCs are reported with perovskite layer thicknesses ranging from ∼720 nm to 1.3 μm. With an optimized ITO top-electrode, the Bi-PSCs generated higher current density under top-illumination by >1 mA/cm2, attaining the highest value of 24.98 mA/cm2. The best Bi-PSC exhibited an efficiency of 19.6% under top-illumination and 18.71% under bottom-illumination, resulting in a high bifaciality factor of ∼0.95. Furthermore, even after employing cover glass encapsulation on the top-electrode, the Bi-PSCs still produced higher current density from top-illumination. Upon bifacial illumination using simulated 1-Sun light as the main illumination and a white LED light albedo of ∼0.21, the champion Bi-PSC demonstrated a current density value of ∼30.00 mA/cm2.

A novel Na2Ca2Si3O9: Tb3+ glass ceramic with high luminescence efficiency and robust thermal stability for white LED lighting application

Given the increasing demand for white light emitting diode (WLED) lighting devices marked by high color rendering indices (CRI) and exceptional thermal stability, there is a burgeoning interest in developing emitters with enhanced performance. Rare earth (RE) ion-activated glass ceramics (GCs) have garnered significant attention due to their outstanding physicochemical and thermal stability, alongside their high luminescence efficiency. In this study, the GCs doped with Tb3+ ions in the Na2O-CaO-SiO2 system matrix were synthesized, incorporating Na2Ca2Si3O9 nanocrystals averaging less than 100 nm in size. Notably, these GC materials demonstrated superior luminescence efficiency in the green light emission under the irradiation of 376 nm light compared to the parent glass. A comprehensive analysis of fluorescence spectra revealed an impressive internal quantum efficiency of 87.34 % for this Tb3+-doped GC. Furthermore, the GC retained 90 % and 84 % of the initial luminescence intensity at 150 °C and 200 °C in comparison to the luminescence level at room temperature, showcasing exceptional resistance to fluorescence thermal quenching. Verification experiments utilized UV LED chip, (Sr, Ca)AlSiN3: Eu2+ red phosphor, BaMgAl10O17: Eu2+ blue phosphor, and Tb3+-doped GC to encapsulate the WLED device, achieving a remarkable CRI of 92, CIE chromaticity coordinates (0.3547, 0.3361), and a correlated color temperature (CCT) of 4550K. In conclusion, the experimental outcomes unequivocally underscore the significant application potential of these Tb3+-doped GCs in the territory of warm WLED lighting.

Co-exposure effect of different colour of LED lights and increasing temperature on zebrafish larvae (Danio rerio): Immunohistochemical, metabolomics, molecular and behaviour approaches

Although there are studies in the literature on the effects of different coloured light-emitting diodes (LEDs) on different organisms, there is limited information on how these effects change with temperature increase. In this study, the effects of blue, green, red and white LED lights on the early development process of zebrafish (Danio rerio (Hamilton, 1822)) were comprehensively investigated. In addition, to simulate global warming, it was examined how a one-degree temperature increase affects this process. For this purpose, zebrafish embryos, which were placed at 4 hpf (hours post fertilization) in an incubator whose interior was divided into four areas, were kept at three different temperatures (28, 29 and 30 °C) for 120 h. The group kept in a dark environment was chosen as the control. The temperature of the control group was also increased at the same rate as the other groups. The results showed that at the end of the exposure period, temperature and light colour caused an increase in body malformations. Histopathological damage and immunopositive signals of HSP 70 and 8-OHdG biomarkers in larval brains, increase in free oxygen radicals, apoptotic cells and lipid accumulation throughout the body, increase in locomotor activity, decrease in heart rate and blood flow, and significant changes in more than thirty metabolite levels were detected. In addition, it has been determined that many metabolic pathways are affected, especially glutathione, vitamin B6 and pyrimidine metabolism. Moreover, it has been observed that a one-degree temperature increase worsens this negative effect. It was concluded that blue light was the closest light to the control group and was less harmful than other light colours. The study revealed that blue light produced results that were most similar to those seen in the control group.

Implications of White Light-Emitting Diode-Based Photoirradiation on Green Synthesis of Silver Nanoparticles by Methanol- and Aqueous-Based Extracts of Bergenia ciliata Leaves.

Bergenia ciliata (BC) is a perennial herb that is frequently used as a traditional medicine. Its leaves and rhizomes are reported to have significant antioxidant, metal-reducing, and chelating properties. Although the rhizomes have the potential to synthesize silver nanoparticles (AgNPs), the leaves are yet to be studied for the green synthesis of metal nanoparticles. Likewise, photoirradiation also plays a significant role in the green synthesis of metal nanoparticles. In the current study, we intended to demonstrate the implications of photoirradiation by white light-emitting diode (LED) on the aqueous and methanol extracts (AE and ME, respectively) of BC leaf-mediated green synthesis of AgNPs. In this regard, the AgNP synthesis of the two extracts was performed in the dark and under 250-lumen (lm) and 825 lm LED bulbs. The physicochemical characterization of the synthesized nanoparticles was also performed, wherein percent nanoparticles yield, morphology of the nanoparticles, shape, size, percent elemental composition, crystallinity, and nanoparticle stability were studied. The nanoparticle-synthesizing potential of the two extracts contradicted significantly in the presence and absence of light, while the AE produced a significantly high number of nanoparticles in the dark (17.26%), and increasing light intensities only attenuated the nanoparticle synthesis, whereas ME synthesized comparatively negligible silver nanoparticles in the dark (1.23%). However, increasing light intensities significantly enhanced the number of nanoparticles synthesized in 825 lms (7.41%). The GCMS analysis further gave a comparative insight into the phytochemical composition of both extracts, wherein catechol and pyrogallol were identified as major reducing agents for nanoparticle synthesis. The influence of light intensities on the physiochemical characterization of AgNPs was predominant. While the size of both the AE- and ME-mediated AgNPs increased considerably (20-50 nm diameter) with increasing light intensities, the percent of silver atoms decreased significantly with increasing light intensities in both the AE- and ME-mediated AgNPs with ranges of 13-18% and 14-24%, respectively. The nanoparticle stability studies suggested that both the AE- and ME-mediated AgNPs were stable for up to 15 days when stored at 4 °C. The stability of both nanoparticles was attributed to the presence of a wide range of phytochemicals. In conclusion, the AE of BC leaves was reported to have significantly higher AgNP-synthesizing potential as compared to the ME. However, AE-mediated AgNP synthesis is attenuated by photoirradiation, whereas ME-mediated AgNP synthesis is enhanced by photoirradiation. The photoirradiation by white LED light increases the size of the AgNPs, while the percent silver composition declines, irrespective of the extract type. Both extracts, however, have nanoparticle stabilizing potential, thereby producing stable nanoparticles.

One-step synthesis of O, P co-doped g-C3N4 under air for photocatalytic reduction of uranium

The photocatalytic reduction of uranium from nuclear wastewater represents a promising method for both uranium extraction and environmental remediation. This approach facilitates the recovery of uranium resources for the nuclear industry while addressing environmental pollution. Despite significant research advancements, there remains a need for cost-effective and environmentally friendly catalytic materials. In this context, we present a two non-metal O, P co-doped g-C3N4 (OPCN) synthesized via a simple one-step thermo-polymerization in air. OPCN demonstrates a high uranium reduction efficiency of 94.9 % under white LED light illumination. Even after five cycles, OPCN maintained a reduction efficiency of 81.7 %, highlighting its stability and reusability. Additionally, OPCN also performs effectively in uranium reduction under natural sunlight and exhibits impressive antimicrobial properties. These features position OPCN as a promising candidate for practical environmental applications.