Daylight Research Articles

Polarised moonlight guides nocturnal bull ants home.

For the first time in any animal, we show that nocturnal bull ants use the exceedingly dim polarisation pattern produced by the moon for overnight navigation. The sun or moon can provide directional information via their position; however, they can often be obstructed by clouds, canopy, or the horizon. Despite being hidden, these bodies can still provide compass information through the polarised light pattern they produce/reflect. Sunlight produces polarised light patterns across the overhead sky as it enters the atmosphere, and solar polarised light is a well-known compass cue for navigating animals. Moonlight produces an analogous pattern, albeit a million times dimmer than sunlight. Here, we show evidence that polarised moonlight forms part of the celestial compass of navigating nocturnal ants. Nocturnal bull ants leave their nest at twilight and rely heavily on the overhead solar polarisation pattern to navigate. Yet many foragers return home overnight when the sun cannot guide them. We demonstrate that these bull ants use polarised moonlight to navigate home during the night, by rotating the overhead polarisation pattern above homing ants, who alter their headings in response. Furthermore, these ants can detect this cue throughout the lunar month, even under crescent moons, when polarised light levels are at their lowest. Finally, we show the long-term incorporation of this moonlight pattern into the ants' path integration system throughout the night for homing, as polarised sunlight is incorporated throughout the day.

Siloxane as Humidity‐Resistant and Stabilizing Additive for Ambient‐Processed Organic Solar Cells

AbstractHigh‐performing organic solar cells (OSCs) being processed in ambient conditions and possessing long‐term stability are desired toward commercialization. Here, resultantly bifunctional additive is proposed for organic active layer, which can greatly enhance humidity endurance during the air‐processing of the active layer and device stability in the meantime. Intriguingly, with 1% octamethyltrisiloxane (3Si) as the additive, casting PM6:L8‐BO active layer even in 90% relative humidity (RH) air could show comparable efficiency to that in N2 condition. Furthermore, the 3Si‐processed active layers also display remarkably enhanced thermal and light stabilities in conventional OSCs. After thermal aging at 85 °C for 1000 h and simulated solar light aging with UV band at 100 mW cm−2 and 55°C for 1000 h, the 3Si‐processed PM6:L8‐BO binary OSCs maintain 91.6% and 86.1% of the initial efficiency, leading to final averaged efficiencies of 16.17% and 15.42%, respectively. The results represent the most stable OSCs based on additive strategy. The universality of siloxane as a humidity‐resistant and stabilizing agent is also confirmed with other active layer systems, paving a way for broader application of the bifunctional additive.

Natural light and visual comfort in algerian collective housing: insights from a post-occupancy evaluation

Natural light is often considered one of the most effective ways to reduce energy consumption in buildings, while ensuring the comfort and well-being of occupants and improving the quality of the indoor environment. Natural light allows people to gather visual information about their environment, making it easier to perform visual tasks safely and comfortably. In this context, this study conducted a post-occupancy evaluation (POE) to assess occupants' satisfaction with the quality of the lighting environment in their living spaces. The ultimate goal of this study was to assess occupants' satisfaction with the lighting environment, and to evaluate their interaction with natural light in their inhabited spaces. The results show that the majority of occupants express dissatisfaction with natural light, which leads them to rely mainly on artificial lighting. Contributing factors are the size of windows, the limited quality of external views and constraints such as the presence of trees and the need for privacy. This occupant-centred research is consistent with an emerging paradigm that emphasises sustainability, ecology, adaptability and the continuous improvement of occupied spaces. The study highlights the need to rethink residential design to optimise daylighting, with the aim of improving occupant comfort and reducing reliance on artificial lighting.

Intelligent Office Lighting Control Using Natural Light and a GA-BP Neural Network-Based System

Intelligent lighting control systems are essential for regulating office illumination. Both illuminance levels and uniformity are important factors influencing the comfort of the office lighting environment. Thus, designing automatic control systems to regulate lighting is essential. This study addresses the issue of natural glare by proposing a method that uses a genetic algorithm (GA) to optimize a backpropagation (BP) neural network model. The model predicts the angle of window slats, with the Sun altitude and azimuth angles as inputs, and the slat angle as the output. For artificial lighting control, a linear function is proposed to manage the relationship between work plane illuminance, natural light intensity, occupancy rates, adjacent luminaire illuminance, and the dimming factor (K). The optimal K value for each luminaire is determined using the least squares method in MATLAB. The intelligent lighting system transmits dimming factors via a ZigBee tree network structure to achieve target illuminance levels. The system’s effectiveness is validated through simulations in DIAlux software, demonstrating that the workplace illuminance in occupied areas reaches 500 lx, while, in unoccupied areas, it reaches 300 lx, with an illuminance uniformity greater than 0.7. This addresses the issue of low illuminance uniformity during daytime. Additionally, the lighting power densities (LPDs) of 1.53 W/m2 and 3.8 W/m2 are well below the specified threshold of 6 W/m2, indicating significant energy savings while maintaining compliance with office lighting standards.

Optimization of the Dynamic External Shading Control for Railway Stations in China Based on Energy Use Intensity (EUI) of Lighting and HVAC Systems

Railway stations are normally designed with glazing façades and skylights to achieve aesthetic requirements and facilitate visual permeability, but this design can lead to significant energy consumption. The implementation of dynamic external shading systems together with appropriate control strategies can significantly reduce the energy consumption of HVAC systems. This study numerically investigated the lighting and cooling energy consumption of railway stations equipped with external shading systems under various climatic zones, window-to-wall ratios (WWRs), skylight-to-roof ratios (SRRs) and roller-shade performance. The study shows that lighting energy consumption varies most significantly when the shading activation threshold is set between 50 and 200 W/m2. The dynamic shading thresholds are influenced by natural lighting and solar heat gain, with the strategy changing from using natural light to reducing solar gain as the SRR increases. This study also provides the optimal activation thresholds and energy-saving rates for railway station buildings in different climatic zones using external roller shades for different external window scenarios. In Guangzhou, using roller shade A in a railway station under the maximum external window scenario achieves energy savings of 36.41%, while in Shanghai and Beijing, the energy savings are 18.12% and 23.13%, respectively. These results provide guidance for the use of dynamic external shading in railway stations in China and for the achievement of energy-reduction targets in the transport and building industries.

Synergistic Strategy toward Enhancing Photosynthesizing Reactive Oxygen Species of Covalent Organic Frameworks

AbstractPhotocatalytic reactive oxygen species (ROSs) plays an important role in photodynamic therapy and photochemical reactions. However, most reported photocatalysts suffer from insufficient utilization of visible light and low conversion of O2, which requires the development of higher performance catalysts toward practical applications. Herein, a series of porphyrin‐based COFs have been prepared. Comparative experimental and theoretical studies have revealed that the synergistic interaction between the two building blocks can significantly enhance the yields of ROSs by independently accomplishing photon harvesting and oxygen capture with smooth energy transfer between them. Particularly, the 1O2 yield of 3P‐Por‐COF is increased to 1.3 and 3.4 times that of the classical PCN‐224 and porphyrin molecular aggregates. Furthermore, the TOF of 3P‐Por‐COF is as high as 271 h−1 with ≈100% selectivity under red light irradiation in catalyzing thioanisole to methyl phenyl sulfoxide. The conversion and stability of degradation of toluene gas under natural light are also superior to the conventional Fenton catalytic system. The present results should contribute to the design of high‐performance frameworks‐based photocatalysts for ROSs production.

Visible light‐responsive azo‐based smart materials: Design, performance, and applications in energy storage

AbstractAzobenzene and its derivatives are the most extensively investigated and applied molecular photoswitches, which can undergo reversible transformation between trans and cis isomers upon irradiation with light at specific wavelengths. Through structural geometry transformation, the property alterations can be integrated into smart materials to meet diverse application requirements. Most azo‐based photoswitches require UV light for activation. However, complete activation within the visible or even near‐infrared light range could offer several benefits for photoswitch applications, including improved biocompatibility, better light penetration, and enhanced solar light utilization efficiency. This review presents an overview of the development of visible‐light responsive azo‐based materials, covering molecular design strategies and their applications in energy storage. Recent efforts aimed at enhancing the performance of azo‐based energy storage materials are highlighted. According to the different strategies for improving energy storage properties, these materials are categorized as those that directly increase isomerization energy and those that introduce phase transition energy. Furthermore, we discuss the challenges and opportunities in this field with a view to inspire further exploration.

Phenothiazine Derivative-Based Photoinitiators for Ultrafast Sunlight-Induced Free Radical Polymerization and Rapid Precision 3D Printing.

In this work, we introduce twenty-six phenothiazine derivatives (PTZs) that were designed and synthesized as visible light photoinitiators. These compounds, in combination with an amine [ethyl 4-(dimethylamino)benzoate (EDB)] and an iodonium salt [di-tert-butylphenyl iodonium hexafluorophosphate (Iod)], could furnish high-performance three-component (PTZs/EDB/Iod) photoinitiating systems that were employed for the free radical polymerization of thick films of a low-viscosity model acrylate resin, namely, trimethylolpropane triacrylate (TMPTA) under visible light and sunlight exposure. A commercial thioxanthone, i.e., isopropylthioxanthone (ITX) was selected to design a reference ITX/EDB/Iod photoinitiating system. Double bond conversions of 87% and 76% were measured for the developed and synthesized photoinitiating systems under 405 and 450 nm light-emitting diode irradiation, respectively, and a conversion as high as 70% could be determined under sunlight irradiation─about 23 times higher than the conversion obtained with the comparable system prepared with the commercial photoinitiator. The relevant photoinitiation abilities and photochemical mechanisms are comprehensively investigated by a combination of techniques including real-time Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, fluorescence spectroscopy, steady-state photolysis, cyclic voltammetry, and electron paramagnetic resonance. Notably, the exceptional performance of the photoinitiators enabled the fabrication of 3D objects with precise morphology and superior resolution through 3D printing and direct laser write techniques. These findings not only provide opportunities for efficient polymerization under artificial and natural light conditions but also pave the way for scalable, cost-effective, environmentally sustainable, and green chemistry-driven curing applications.

Evaluation of the clinical efficacy of modified LSC transplantation plus BCL implantation in the treatment of pterygium

ObjectiveTo explore the clinical efficacy of modified limbal stem cell transplantation(Modified LSC transplantation) and bandage contact lens(BCL) implantation in pterygium surgery.MethodsA total of 479 patients with primary pterygium who were admitted to our hospital from March 2019 to March 2023 were randomly divided into three groups: the normal group (Group A: 89 patients), the control group (Group B: 195 patients), and the modified group (Group C: 195 patients). Each group received different intervention measures. Group A did not undergo surgical treatment and were required to follow up as outpatients. Group B received LSC transplantation combined with interrupted suturing plus BCL, whereas Group C received modified LSC transplantation combined with BCL. The degree of corneal irritation symptoms, wound healing and graft status under slit lamp, incidence and recurrence rate of complications, tear film rupture time, tear secretion test, intraocular pressure, ocular surface inflammation response(IL-1β, PGE2, TNF-α, VEGF), and visual quality were compared and analyzed at various time points after surgery.ResultsCompared with those in the Group B, patients in the Group C experienced faster normalization of corneal epithelium recovery, fewer corneal irritation symptoms, and better wound healing. The break-up time (BUT) of the tear film at 1 week to 1 year postoperatively was significantly greater in the Group C than Group B, with values approaching those of Group A by 3 months (P < 0.05). The Schirmer test results revealed a similar trend to that of the BUT. Further analysis of intraocular pressure (IOP) at different time points revealed no significant differences among the three groups at postoperative Day 1. However, due to the use of corticosteroid eye drops postoperatively, IOP was greater in both the Group B(17.24 ± 2.12 mmHg) and Group C (17.02 ± 2.37 mmHg) than Group A (13.92 ± 1.57 mmHg) at 1 week. By 1 month, Group C had a lower IOP (15.77 ± 1.63 mmHg) than Group B(17.78 ± 2.41 mmHg). There were no significant differences in IOP among the three groups from 3 months to 1 year (P > 0.05). The ELISA results indicated that the expression levels of the ocular surface inflammatory factors IL-1β, TNF-α, PEG2, and VEGF in the Group C were lower than those in Group B from 1 week to 1 year post surgery. Under both natural light and low-light conditions (spatial frequency/6 cd), Group C had better best-corrected visual acuity and contrast sensitivity than Group B at 1 week to 1 year postoperatively. Additionally, Group C had lower corneal higher-order aberrations (including astigmatism, spherical aberrations, and total higher-order aberrations) and superior vision-related quality of life scores at 1 year postoperatively than Group B, with statistically significant differences (P < 0.05).ConclusionModified LSC transplantation combined with BCL implantation provided superior treatment outcomes for patients with pterygium, which was worthy of further clinical promotion.

Phycogenic nanoparticles efficiently catalyse pesticide degradation through a novel metabolic pathway utilizing solar light

Cypermethrin (Cy) is a widely used insecticide, leading to significant environmental contamination in homes and agricultural areas. Effective methods to minimize or eliminate insecticidal residues are essential. Seaweeds, traditionally used in agriculture as soil conditioners, offer a promising solution for remediating pesticide-contaminated soils through biogenic nanoparticle synthesis. In this study, we synthesized biogenic silver nanoparticles (UL-AgNPs) from the green seaweed Ulva lactuca Lin (Ulvaceae) to degrade Cypermethrin. The UL-AgNPs were characterized using UV-Visible spectroscopy, Scanning Electron Microscopy equipped with Energy dispersive X-ray spectroscopy, Fourier Transform Infra-red spectroscopy, X-ray diffraction, Dynamic light scattering and zeta potential analysis, confirming their presence, size (81.29 nm), structure and stability. Response surface methodology (RSM) was used to assess the catalytic concentration of photocatalyst for degradation of pesticide including variables, Cy concentration and destined exposure time duration. The degradation efficiency of UL-AgNPs was evaluated, with the highest degradation (91.2%) achieved at pH 7 after 12 hours using 16.6 mg L-1 of UL-AgNPs, following pseudo-first order kinetics with a rate of 2.7 hour-1. GC-MS and UV-Visible spectroscopy revealed a novel degradation pathway, where Cypermethrin was broken down into compounds like Tetradecane, Dodecane, and Tetracosanoic acid through ester cleavage and benzene ring breakdown. The study also demonstrated the reusability of UL-AgNPs for four cycles, highlighting their potential for sustainable environmental management by reducing the long-term hazards of Cypermethrin.

Pseudologic Optical Circuit Method for Advanced Color Sensing in IGZO Phototransistor Arrays with Chlorophyll Absorption Layers.

Recently, the elimination of color filters has become a key focus in photodetector research because of the potential to create more compact and cost-effective sensor systems. In this study, a novel concept of a filter-free color-discrimination photosensor using an indium gallium zinc oxide (IGZO, In/Ga/Zn = 3.1:2.6:1.0)-based phototransistor with an integrated chlorophyll absorption layer (CAL) and a solution-processed oxide absorption layer (SAL) was developed. Chlorophyll, known for its role in photosynthesis as a natural light absorber, offers distinct characteristics compared to conventional photodetectors (i.e., SAL/IGZO), whereby the photoresponsivity decreases with increasing wavelength. Using the ability of chlorophyll to absorb blue and red light, the proposed CAL/IGZO phototransistor exhibited a higher photoresponsivity to red light than to green light. The device achieved a photoresponsivity of 1570 A/W for red light and 681 A/W for green light, with a photosensitivity of 8.35 × 105 and 8.96 × 104 and a detectivity of 8.47 × 1011 and 6.80 × 1010 Jones, respectively, under an illumination intensity of 1 mW/mm2. Furthermore, by integrating the proposed CAL/IGZO phototransistor with a SAL/IGZO phototransistor, which exhibited a different order of photoresponse across RGB wavelengths, an innovative color-discrimination pixel pseudologic circuit was successfully developed. The capability of this circuit to distinguish colors across various light intensities was validated through experimental data and SPICE simulations, with the output voltage ranges confirmed as -2.61 to -3.51 V for red, 1.56 to 2.69 V for green, and -0.22 to -0.68 V for blue over light intensities from 0.1 to 3 mW/mm2. This innovative approach allows effective color detection without conventional color filters, providing an advanced solution for photodetection technologies.

"How Can We Help You?" Older Adults' and Care Partners' Perspectives on Improving Care in Hospital: A Mixed Methods Study.

Hospitalized older adults have unique physical, emotional, and psychosocial needs. We sought to understand older patients' and care partners' experiences with multicomponent interventions that support age-friendly care and identify areas for improvement. We conducted a mixed methods study using surveys and interviews to explore older adult patients' (65 years or older) and their care partners' experiences with hospital-delivered multicomponent initiatives. We recruited participants from the Geriatric Rehabilitation (GRU) and Musculoskeletal (MSK) Rehabilitation units in a Canadian academic hospital from October 2021 to April 2022 until we reached data saturation and no new themes emerged. We recruited 18 participants, 10 patients (mean age 78 years, 80.0% female) and 8 care partners (mean age 61, 87.5% female). Surveys revealed overall positive experiences with multicomponent interventions. Interviews revealed five themes: 1) various forms of companionship for patients, 2) recreation and entertainment, 3) physical activity, 4) communication, and 5) pleasant physical environment. Having forms of companionship and proper communication with the care team were highlighted as areas of importance. Physical activity was highly valued, but participants expressed hesitation around safety of mobilizing without physiotherapists. Recreational activities helped distract from social isolation during a hospital stay and participants had diverse preferences for activities. Participants had strong memories of the physical environment, including the lack of natural light, institutionallike décor, and smells. Companionship, recreation and entertainment, physical activity, communication, and the physical environment were important to hospitalized patients and their care partners. Hospital administrators and policy makers should consider these when targeting areas to improve care for the aging population.

Optimized design and comparative analysis of double-glazed photovoltaic windows for enhanced light harvesting and energy efficiency in cold regions of China

This study investigates the daylighting performance and energy efficiency optimization strategies of double-glazed photovoltaic windows (DS-STPV) in cold regions of China. By conducting a comprehensive comparative analysis with traditional and energy-efficient window systems, this research aims to identify high-efficiency building solutions tailored to extreme climatic conditions. Amidst the escalating global energy demand and the pressing need for energy conservation and emission reduction, Building-Integrated Photovoltaic (BIPV) technology is increasingly recognized for its potential and value as a critical method for harnessing green energy. However, the widespread adoption of BIPV technology faces several challenges, including cost-effectiveness, conversion efficiency, system stability, and architectural aesthetic integration. Utilizing the T&A House from the 3rd International Solar Decathlon as an empirical case study, this research employs Ecotect and DesignBuilder simulation software to systematically evaluate the daylighting effect and energy performance of DS-STPV. The analysis considers various key design parameters, including photovoltaic cell coverage, window orientation, and window-to-wall ratio. Through refined modeling and multi-dimensional analysis, this study aims to identify the optimal design configurations of DS-STPV windows in cold regions, with the goal of simultaneously achieving superior natural lighting quality and significant building energy efficiency. The findings indicate that a south-facing DS-STPV window design with approximately 30% photovoltaic cell coverage and a window-to-wall ratio of 30% effectively balances daylighting requirements and energy efficiency in cold regions of China. This design strategy not only ensures an abundance of natural light in the room, but also significantly reduces the building’s energy consumption, proving the superior performance of DS-STPV windows in cold climates. In addition, the unique optical properties of DS-STPV windows reduce glare, further improving the overall quality of the indoor environment. In summary, this study provides a robust scientific foundation for the application of DS-STPV windows in cold regions, offering practical guidance and reference for optimizing energy efficiency and facilitating green transformation in future building design.

EFFECT OF GREEN AND UVA SPECTRA, AND PRE-HARVEST TREATMENTS ON BIOMASS AND METABOLITE YIELDS OF INDOOR CULTIVATED STEVIA REBAUDIANA

Stevia rebaudiana is a high-value crop due to the strong commercial demand for its metabolites (steviol glycosides, SG) as an organic low-caloric sweetener with up to 300 times the sweetness of conventional sugar. Two experiments were conducted in this study. In the first experiment, treatments with varying green (GR1 & GR2), UVA (UV1 & UV2) and treatments that had both (UVGR1, UVGR2) were used. In the second experiment, separate set of plants were grown under base red-blue (RB) and natural sunlight before being transferred to GR2, UV2, UVGR2, and monochromatic light treatments of blue, green and UVA, for 3 and 10 days before harvest. RB and sunlight were used as the control for artificial and natural light respectively. Plants grown under the UVGR1 had the highest dry leaf biomass accumulation of 4.75 g plant-1 (P<.05), 458% and 660% higher than the RB (0.98 g plant-1) and natural sunlight (0.72 g plant-1) controls. UVA had the highest metabolite (Stevioside + Rebaudioside A) concentration of 27% (P<.05) compared to the RB and sunlight controls at 17.24% and 15% respectively. The 10 day pre-harvest treatment with blue supplemented light yielded a dry biomass of 1.87 g plant-1, a 190% increase compared to the RB control. However, the 3 day pre-harvest treatment had higher metabolite yields improvements compared to 10 day treatments with the highest yield obtained of 21.10% in 3-day pre-harvest irradiation that had supplemental UVA and blue light. UVGR1 was the most productive lighting strategy, resulting in the highest overall metabolite yield per plant.

Determinants of spatial variation of ventilation quality and natural lighting in the residential environment of Dekernes city using GIS

Determinants of spatial variation of ventilation quality and natural lighting in the residential environment of Dekernes city using GIS

Daily Light Integral Maps for Agriculture Lighting Design in Spain

The Daily Light Integral (DLI) is a key metric to optimise plant cultivation, influence photosynthesis, morphology, yield, and nutritional quality. Our study focuses on (i) the creation of the spatiotemporal DLI map for a representative Mediterranean country, Spain, (ii) the presentation of the improved semi-automatic DLI mapping workflow, (iii) the challenge of the comparability of different DLI value scalings in global (continent) and local context (country). DLI maps provide essential insights into the spatial and temporal distribution of natural and artificial light, critical for optimizing agricultural practices and enhancing crop yields. Spain's diverse topography and climate create significant regional and seasonal variations in DLI values. Using data from SunTracker Technologies and global weather stations, we developed detailed DLI maps at 30-meter resolution. These maps reveal high DLI values in coastal and southern regions, especially in summer, and lower values in northern and interior regions during winter. Our findings emphasize the importance of tailored lighting strategies in agriculture, suggesting higher scaling (from 5 to 2 mol·m−2·d−1) resolution for European contexts. This research underpins the development of smart agricultural systems that both quantitatively and qualitatively regulate lighting conditions (supplementary light and shading management) to maximize crop productivity and sustainability. Integrating DLI maps with IoT and AI technologies offers predictive insights for precision agriculture, highlighting the need for advanced training to leverage these tools effectively.

An effective photocatalytic decomposition of azo dyes by NiO/ZnO/g-C3N4 ternary nanocomposite under solar light excitation

An effective photocatalytic decomposition of azo dyes by NiO/ZnO/g-C3N4 ternary nanocomposite under solar light excitation

Enhanced solar light photocatalytic degradation of tetracycline by aero-GaN and ZnO microtetrapods functionalized with noble metal nanodots

Enhanced solar light photocatalytic degradation of tetracycline by aero-GaN and ZnO microtetrapods functionalized with noble metal nanodots

Synthesis and characterization of multi-responsive iron oxide nanoparticles: Evaluation of antibacterial properties and photocatalytic activity

Cape gooseberry (CG) plant leaf extract-mediated iron oxide nanoparticles (CG-IO NPs) were fabricated for antibacterial research. The ideal concentration of the precursor salt, pH (11) of the reaction mixture, reducing agent to precursor salt ratio, and the production time of iron oxide nanoparticles were 5 mM, 9.0, 3:7, and 25 min, respectively. The iron oxide nanoparticles were tested using ultraviolet–visible absorption spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric/differential thermal analysis (TG/DTA), and Fourier transform infrared (FTIR) spectroscopy. FTIR spectroscopy was used to identify functional groups of the compounds, including the carbonyl, CH, and OH bands that reduced and produced nanoparticles. The size and shape of the synthesized CG-IO NPs were determined by TEM and dynamic light scattering, with the median and mean size of 13.9 nm and 15.8 nm, respectively. The thermal stability of the synthesized CG-IO NPs was assessed using TG/DTA in a nitrogen atmosphere. The elements and oxidation states of the CG-IO NP components were examined by XPS. The luminosity of the CG-IO NP was examined using PL spectroscopy. The synthetic CG-IO NPs exhibited strong antibacterial effects against dangerous bacteria, such as Salmonella enterica (S. entirica), Escherichia coli (E. coli), Streptococcus agalactiae, and Staphylococcus aureus. CG-IO NPs assisted in water reclamation by decomposing Malachite Green dye under solar light irradiation.

Preparation and characterization of functionally antibacterial multi-layer lignin core-shell structure material with adsorption and high efficiency of photocatalysis for Cr(Ⅵ)

Wastewater with chromium is a common heavy metal pollution in industrial pollution, affecting health of human seriously, while adsorption and photocatalysis are efficient for Cr(Ⅵ) removal. The multi-layer lignin core-shell structure materials were prepared with kraft lignin/polydopamine core-shell structure material, using non-covalent bonding to induce the in-situ induction of TiO2. The hydroxyl group of kraft lignin and the amino group of polydopamine provided abundant adsorption active sites with adsorption capacity being 299mg/g at pH of 2. The adsorption process conformed to the Freundlich isotherm model and the pseudo-second-order kinetic model. The removal rate of Cr(Ⅵ) reached more than 99.9% within 10min under simulated solar light with influence of adsorption and photocatalysis. The multi-layer lignin core-shell structure materials presented excellent antibacterial activity, with the inhibition rate against S.aureus and E.coli being 40% under dark conditions and 99% under simulated solar light because h+ or ·OH producing by TiO2. The antibacterial multi-layer lignin core-shell structure materials showed good universality in water pollution treatment.