Sunlight Illumination Research Articles

GO/ZnO-based all-solid-state photo-supercapacitors: Effect of GO:ZnO ratio on composite properties and device performance

The development of photo-supercapacitors (PSC), which is an important step towards more efficient use of solar energy and reducing the carbon footprint, will be possible with a better understanding and manipulation of the properties of photo-active dual-effect electrodes used in these devices. This work demonstrates the existence of critical ratios for graphene oxide/zinc oxide (GO/ZnO) composites in terms of PSC performance. In this ratio, both photoluminescence intensity in the UV region and the defect densities determined from electron paramagnetic resonance spectroscopy are low. Moreover, the specific capacitance of the best-performing GO/ZnO composites increased 2.7-fold and reached 6612 mFg−1 after UV illumination. Besides, this device showed exceptional stability over 30,000 galvanostatic charge and discharge cycles with 99.6 % capacitance retention and 100 % Coulombic efficiency. The maximum energy density of 6.3 Whkg−1 and power density of 625 Wkg−1 were calculated for a 2.5 V operating voltage under UV illumination. As proof of concept, a digital watch was powered for more than 1 h and 40 min with GO/ZnO-based PSC charging under UV and AM1.5 sunlight illumination at 0.2 Ag−1 for 50 and 130 s, respectively.

Integration of WO3-Doped MoO3 with ZnO Photocatalyst for the Removal of 2-Nitrophenol in Natural Sunlight Illumination

Environmental contamination has become the most pressing issue in recent years. The value of clean water to mankind has sparked interest in heterogeneous photocatalysis. In this study, a novel photocatalyst has been synthesized by integrating WO3-doped MoO3 (WDM) and ZnO through composite formation. The composite nature of the synthesized photocatalyst was confirmed due to the presence of hexagonal ZnO and orthorhombic WDM phases in XRD pattern and scanning electron micrographs. Solid-state absorption spectra and a bandgap analysis showed that WDM-spectral ZnO’s response was better than that of pure ZnO. PL and EIS unveiled the effective role of WDM in suppressing the e−–h+ recombination process and charge-transfer resistance, respectively, in ZnO. The photocatalytic studies showed that WDM-ZnO was able to remove ~90% of 30 ppm 2-nitrophenol (2-NP) with a rate of 1.1 × 10−2 min−1, whereas ~65% 2-NP was removed by ZnO (6.1 × 10−3 min−1 rate) under the exposure of natural sunlight (800 × 102 ± 100 lx). Moreover, ~52% higher total organic carbon (TOC) removal was observed by WDM-ZnO as compared to ZnO. The photocatalytic removal of 2-NP by the produced photocatalysts followed the Langmuir–Hinshelwood kinetic model, as shown by the kinetic studies. The reactive oxygen species (ROS)-trapping established that the photocatalytic removal mechanism of 2-NP over WDM-ZnO in sunlight illumination was mainly triggered by the superoxide anion (O2•−) radical, however, the minor role of hydroxyl (•OH) radicals cannot be completely ignored.

High-Efficient Anti-Icing/Deicing Method Based on Graphene Foams.

Anti-icing/deicing has always been a focal issue in modern industries. A novel anti-icing/deicing material based on graphene foams (GF) is prepared in this paper, which integrates multiple functions, including electrothermal conversion, photothermal conversion, and superhydrophobicity. The GF sheet is used as a bottom layer bonded on the protected substrate, which is covered by a polymeric composite coating filled with TiN and SiO2 nanoparticles. Electric heating and light heating experiments are performed to study the anti-icing/deicing performances of such a GF-based material. It is found that, under the unique action of electric fields, a voltage of only 1 V is needed to increase the surface temperature from minus tens of degrees to the one above zero within 400 s, which is much lower than their previous counterparts of more than 10 V to achieve the same unfreezing effect. A slight increase of the applied voltage to 1.5 V can even result in a remarkable increase of the surface temperature from room temperature to more than 150 °C within 200 s, in contrast to existing electric heating techniques to attain peak temperatures of about 100 °C at the expense of tens of volts. Such performances enable the GF-based material to achieve an outstanding electrothermal energy conversion rate of more than 90%. Furthermore, with the help of sunlight illumination in addition to the electric power, not only can the critical voltage to prevent icing be reduced but also a much more rapid and adequate removal of ice or frost from the surface can be realized compared with the deicing/defrosting performance under either electric or light field alone. All of these results demonstrate the obvious advantages of the present method in superior energy utilization efficiency and universal applicability to dark and sunlight environments, which should be particularly useful for at-all-cost protection of key components in industrial equipment from icing.

Photo-thermal conversion properties of Cr, Mo, and W nanofluids in polyethylene glycol prepared by laser ablation in liquid method for direct absorption solar collectors applications

Nanofluids (NFs) are promising materials for solar-energy harvesting. The main drawback of NFs is their instability and longtime preparation methods that the purpose of this work relies on overcoming these problems. The Cr, Mo, and W NFs in polyethylene glycol (PEG) were synthesized by laser ablation in liquid (LAL). The capability of the prepared NFs in photo-thermal conversion was investigated under 60 min solar simulator irradiation at 1 Sun and thermo-physical properties of them (SER, Etotal, E%, and B) were calculated, indicating Cr NF has the highest photo-thermal conversion efficiency (E%≅85% at its near-to-surface). The comparison of nanoparticles radius obtained with transmission electron microscopy (TEM) and the hydrodynamic radius obtained with dynamic light scattering (DLS) methods, reveals that nanoparticles were surrounded by a thick layer of PEG molecules, leading to the super-stable and long-life NFs. The effect of the nanoparticle concentration, light intensity, and consecutive heating–cooling cycles on the performance of NFs was investigated. Under 1 h sunlight illumination (∼850–960 W/m2 intensity), the surface temperature of Cr NF reaches ≅ 65 ℃, indicating the Cr NF is highly eligible for photo-thermal conversion in the real outdoor condition. The low cost and simplicity of the synthesis method, no need to use stabilizer, super durability, high-thermal stability, low rate constant of heat dissipation, and high photo-thermal conversion efficiency confirms that Cr/PEG NF can be used as potential working fluid for direct absorption solar collectors (DASCs).

Enhancing photoelectrocatalytic activity and stability of p-Cu2O photocathode through n-TiO2 coating for improved H2 evolution reaction

This article presents a novel approach to improve both the photoelectrocatalytic activity and stability of the p-Cu2O photocathode. The approach involves the coating of an n-type TiO2 layer using e-beam evaporation with precise controllability of the coating thickness onto the p-type Cu2O electrode, forming a TiO2/Cu2O p/n heterojunction. Such a p/n junction enhances the photoelectrocatalytic activity of the Cu2O electrode by promoting the separation of the photo-generated charge carriers. Additionally, the large bandgap TiO2 coating layer serves as protection, reducing the photocorrosion of Cu2O, thereby improving the stability of the electrode. The n-TiO2/p-Cu2O photocathode shows superior photoelectrochemical H2 evolution activity in comparison to the pristine p-Cu2O photocathode. We have found that the thickness and annealing temperature of TiO2 influence strongly the photocurrent and stability of the resultant TiO2/Cu2O photocathode. The best TiO2/Cu2O photocathode was achieved by coating a 50 nm thick TiO2 layer onto the Cu2O, followed by annealing at 350 °C. This configuration exhibited a large onset photovoltage of 0.58 V vs RHE and a catalytic current density of ∼0.9 mA·cm‒2 at 0 V vs RHE in a pH 7 phosphate buffer, under standard 1 Sunlight illumination.

Efficient red light polymerization facilitated by low energy excitation based on a single-atom substituted naphthalimide

Photoinduced polymerization with low-energy, longer wavelength light has attracted enormous attention in material/biological applications owing to its unique advantages of greener and deep curing compared to conventional harsh UV-triggered polymerization. However, the low-energy polymerization methods often rely on heavy atom-containing sensitizers or suffer from the slow solidification process, which restricts their applicability in several areas. Herein we construct a novel efficient photoinitiating system based on a single-atom substituted pure organic triplet photosensitizer, prepared from a common naphthalimide chromophore through a simple one-pot process, and exemplified its potential to enable the efficient and rapid polymerization (just a few tens of seconds) of acrylate upon low-intensity (0.36 W/cm2) red-light illumination. We show that the single atom replacement (oxygen with sulfur) can redshift the absorption profile of naphthalimide chromophore over 150 nm and also effectively promotes its intersystem crossing efficiency (from 0 to 86.4%). For the first time, the thionaphthalimide (NIS) was introduced in triplet-triplet annihilation upconversion, showing a high upconversion quantum yield of (4.4–12.9%) with a large anti-Stokes shift (0.65–0.80 eV) in various solvents. We successfully employed the upconverted annihilator's singlet to trigger the photoinitiator via Förster resonance energy transfer (FRET) for polymerization. Furthermore, this photoinitiating system is found to be effective enough to be operable under sunlight illumination and useful for the fabrication of high-quality flexible products via photolithography approach. Thus, our results are beneficial for the future design of eco-friendly, low-energy activated chemical conversion systems.

Late paleozoic climate revealed by coral fossil patterns.

The study of coral fossils with clear growth lines inShiqiantan Formation (310 Ma) in China showed the growth line increments of a single coral growing in this area is related to the sunlight illumination time. Moreover, the daily increment of the growth line caused by calcium carbonate depositions has an unusual bimodal curve. The study of this bimodal curve indicated Shiqiantan had evident four-season changes in the Late Carboniferous period, and the climate at that time was similar to that of modern North China. The present paper updates the oldest existing record of climate analysis materials and provides important information for the study of Late Paleozoic climate, as well as the ancient obliquity of ecliptic.

Enable Multi-Stimuli-Responsive Biomimetic Actuation with Asymmetric Design of Graphene-Conjugated Conductive Polymer Gradient Film.

In this paper, multiresponsive actuators based on asymmetric design of graphene-conjugated poly(3,4-ethylene dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) gradient films have been developed by a simple drop casting method. The biomimetic actuation is attributed to the hygroscopic expansion property of PEDOT:PSS and the gradient distribution of graphene sheets within the film, which resembles the hierarchical swelling tissues of some plants in nature. Graphene-conjugated PEDOT:PSS (GCP) actuators exhibit reversible bending behavior under multistimuli such as moisture, organic vapor, electrothermal, and photothermal heating. Noticeably, the bending curvature reaches 2.15 cm-1 under applied voltage as low as 1.5 V owing to the high electrical conductivity of GCP actuator. To mimic the motions of nyctinastic plants, a GCP artificial flower that spreads its petals under sunlight illumination has been fabricated. GCP actuators have been also demonstrated as intelligent light-controlled switches for light-emitting diodes and smart curtains for thermal management. Not only do the GCP gradient films exhibit potential applications in flexible electronics and energy harvesting/storage devices but also the facile fabrication of multiresponsive GCP actuators may shed light on the development of soft robotics, artificial muscles, wearable electronics, and smart sensors.

Nitrogen Photoelectrochemical Reduction on TiB2 Surface Plasmon Coupling Allows Us to Reach Enhanced Efficiency of Ammonia Production.

Ammonia is one of the most widely produced chemicals worldwide, which is consumed in the fertilizer industry and is also considered an interesting alternative in energy storage. However, common ammonia production is energy-demanding and leads to high CO2 emissions. Thus, the development of alternative ammonia production methods based on available raw materials (air, for example) and renewable energy sources is highly demanding. In this work, we demonstrated the utilization of TiB2 nanostructures sandwiched between coupled plasmonic nanostructures (gold nanoparticles and gold grating) for photoelectrochemical (PEC) nitrogen reduction and selective ammonia production. The utilization of the coupled plasmon structure allows us to reach efficient sunlight capture with a subdiffraction concentration of light energy in the space, where the catalytically active TiB2 flakes were placed. As a result, PEC experiments performed at -0.2 V (vs. RHE) and simulated sunlight illumination give the 535.2 and 491.3 μg h-1 mgcat-1 ammonia yields, respectively, with the utilization of pure nitrogen and air as a nitrogen source. In addition, a number of control experiments confirm the key role of plasmon coupling in increasing the ammonia yield, the selectivity of ammonia production, and the durability of the proposed system. Finally, we have performed a series of numerical and quantum mechanical calculations to evaluate the plasmonic contribution to the activation of nitrogen on the TiB2 surface, indicating an increase in the catalytic activity under the plasmon-generated electric field.

The Impact of Different Green Synthetic Routes on the Photocatalytic Potential of FeSnO2 for the Removal of Methylene Blue and Crystal Violet Dyes under Natural Sunlight Exposure

FeSnO2 nanocomposites were synthesized via the green method using aqueous leaf extracts of Lawsonia inermis and Phyllanthus embilica plants. The role of polyphenols based on reduction potentials for the synthesis of FeSnO2 was also highlighted. The synthesized materials were examined by using TGA and DSC, FT-IR, XRD, and SEM with EDX analysis. Tetragonal rutile and distorted hexagonal structures were observed in SEM images of the FeSnO2 nanocomposites and compared with an FeSnO2 nanocomposite prepared using the sol-gel method. Scherer’s formula yielded crystallite sizes of 29.49, 14.54, and 20.43 nm; however, the average crystallite size assessed employing the Williamson–Hall equation was found to be 20.85, 11.30, and 14.86 nm by using the sol-gel and green techniques, using extracts from Lawsonia inermis and Phyllanthus embilica. The band gap was determined by using the Tauc and Wood equations, and photocatalytic activity was analyzed to determine the degradation of methylene blue (MB) and crystal violet (CV) under the illumination of natural sunlight. It was observed that the sample prepared by means of the green method using the leaf extract of Lawsonia inermis showed the best photocatalytic activity of 84%, with a particle size of 14.54 nm, a 3.10 eV band gap, and a specific surface area of 55.68 m2g−1.

Tailoring Morphology in Hydrothermally Synthesized CdS/ZnS Nanocomposites for Extraordinary Photocatalytic H2 Generation via Type-II Heterojunction

CdS@ZnS core shell nanocomposites were prepared by a one-pot hydrothermal route. The morphology of the composite was tuned by simply changing the Zn2+ precursor concentration. To characterize the samples prepared, various techniques were employed, including XRD, FESEM, TEM, XPS and UV-vis DRS. The band gaps of CdS and ZnS were measured to be 2.26 and 3.32 eV, respectively. Compared with pure CdS, the CdS@ZnS samples exhibited a slight blue shift, which indicated an increased band gap of 2.29 eV. The CdS@ZnS core shell composites exhibited efficient photocatalytic performance for H2 generation under simulated sunlight illumination in contrast to pure CdS and ZnS. Additionally, an optimized H2 generation rate (14.44 mmol·h−1·g−1cat) was acquired at CdS@ZnS-2, which was approximately 4.6 times greater than that of pure CdS (3.12 mmol·h−1·g−1cat). Moreover, CdS@ZnS heterojunction also showed good photocatalytic stability. The process of charge separation over the photocatalysts was investigated using photoelectrochemical analysis. The findings indicate that the CdS@ZnS nanocomposite has efficient charge separation efficiency. The higher H2 generation activity and stability for CdS@ZnS photocatalysts can be attributed to the intimate interface in the CdS@ZnS core–shell structure, which promoted the light absorption intensity and photoinduced charge separation efficiency. It is expected that this study will offer valuable insights into the development of efficient core shell composite photocatalysts.

Optimized Design of Skylight Arrangement to Enhance the Uniformity of Indoor Sunlight Illumination

The use of skylights in buildings introduces natural light into the interior space, thereby reducing the reliance on artificial lighting and aligning with the principles of low carbon and environmental sustainability. To ensure optimal indoor lighting quality, it is essential to optimize the arrangement of skylights to strike a balance between high average illumination and uniformity of illumination. Recent initiatives by the Chinese government have emphasized the construction and renovation of numerous gymnasiums. In this research, a novel approach based on optimized algorithms was employed to design skylights and improve the uniformity of indoor illuminance. Simulation results demonstrated that the skylight arrangements derived from the optimization algorithms exhibited significantly higher levels of illumination uniformity, while maintaining comparable average illumination and skylight areas, when compared to conventional designs. Additionally, the study employed genetic algorithms to optimize the skylight arrangement for a specific gymnasium, resulting in a remarkable 32% increase in illumination uniformity. The study also accounted for obstacles and seating in the skylight design, and the genetic algorithm generated desirable skylight arrangements with respective increases of 32% and 21% in illumination uniformity for scenarios involving obstacles and seating. Overall, this study underscores the potential of optimized algorithms in the design of skylights for green buildings, offering valuable insights for future research endeavors in this field.

Piezo-plasmon phototronically enhanced direct solar-chemical translations from Au decorated perovskite BiFeO3 sea urchin-like 3D nanostructures

Bismuth ferrite-based oxide nanostructures were chemically processed to offer an effective solution for the growing energy crisis and environment pollution by employing them as photoelectrodes for water splitting reactions and remediation of organic pollutants through photocatalysis. The influence of plasmonic effects via gold (Au) incorporating the physicochemical properties and their resulting impact on the application performance has been studied systematically. The processed materials were examined using X-ray diffraction (XRD), absorbance, and transmission electron microscopic instruments. Au interaction in the host BFO nanoparticle surface was affirmed through an in-depth examination of their photoelectron spectroscopic data. Plasmonic effect was also visualized in the absorbance spectra along with a significant change in the optical spectrum on Au decoration. Photoluminescence spectra approved the quality of defect states to be significantly influenced by the BFO nanoparticles and the Au nanoparticles influenced charge transmigration and separation. Enhanced photocatalytic and photoelectrochemical performance from the Au-decorated BFO nanostructures was evaluated through comparative analysis of pristine BFO. Time-dependent photocurrent density studies also proved the stability of processed photoelectrode materials in efficient water splitting via Au nanoparticles, which actually enhanced the charge transfer efficiency by offering improved conductivity as studied via Nyquist plots. The piezophotocatalysis activity of the nanocomposite exhibited a high degree of degradation of organic pollutants and better hydrogen production from water splitting reaction upon direct sunlight illumination.

Janus carbon nitride membrane for robust and enhanced nanofluidic power generation from wastewater

Nanofluidic membranes have shown great promise in harvesting osmotic power. Yet, previous studies extensively focused on osmotic energy released by the mixing of seawater and river water, while there exist many other osmotic energy sources, such as the mixing of wastewater with other water. However, harvesting the osmotic power of wastewater is highly challenging because it requires the membranes to have environmental remediation capabilities to avoid pollution and biofouling, which has not been satisfied by previous nanofluidic materials. In this work, we demonstrate that a Janus carbon nitride membrane can be used for simultaneous power generation and water purification. The Janus structure of the membrane generates asymmetric band structure and therefore a built-in electric field, facilitating electron-hole separation. As a result, the membrane shows strong photocatalytic capability, which efficiently degrades organic pollutants and kills microorganisms. In particular, the built-in electric field also facilitates ionic transport, significantly promoting the osmotic power density up to 30 W/m2 under simulated sunlight illumination. The power generation performance can be robustly kept with or without the presence of pollutants. This study will shed light on the development of multi-functional power generation materials for the comprehensive utilization of industrial wastewater as well as domestic sewage.

In Situ Synthesis of 3D BiOCl-Graphene Aerogel and Synergistic Effect by Photo-Assisted Activation of Persulfate for Methyl Orange Degradation.

BiOCl/graphene aerogel graphene (BGA) was successfully obtained by in situ hydrothermal synthesis, and the chemical, structural, morphological, and photocatalytic properties were systematically characterized. BGA with the doping amount of BiOCl at 20% (BGA-4) exhibited the optimal activation efficiency for persulfate (PDS) on the degradation of methyl orange (MO) under simulated sunlight (SSL) illumination as compared to the pure graphene (GA) and aerogel composites with different BiOCl content. The influence of various reaction parameters on the MO removal efficiency, such as the reaction system, catalyst activator dose, PDS concentration, BiOCl doping amount, and the initial pH of the solution, was investigated. Under optimum conditions, the catalytic efficiency of BiOCl-doped GA with the mass ratio of 20% (BGA-4) was 5.61 times that of GA. The strengthening effect of BGA-4 benefited from the synergistic effect of 1O2, O2·- and the generation and rapid electron transfer of photo-induced electron (e-) in the BGA-4/SSL/PDS system. Considering the superior stability and recyclability of BGA-4, the BGA-4/SSL/PDS system exhibits great potential in actual wastewater treatment.

Enhanced photocatalytic performance of auto-combusted nanoparticles for photocatalytic degradation of azo dye under sunlight illumination and hydrogen fuel production

In this study, an innovative nanomaterial was synthesized for hydrogen production from methanolysis on sodium borohydride (NaBH4) in order to be a solution for future energy problems. The nanocomposite containing FeCo, which does not contain noble metals, and whose support material is Polyvinylpyrrolidone (PVP), was synthesized by means of a thermal method. TEM, XRD and FTIR characterization methods were used for the analysis of the morphological and chemical structure of the nanocomposite. Nanocomposite particle size was found to be 2.59 nm according to XRD analysis, and 5.45 nm according to TEM analysis for scale of 50 nm. For catalytic properties of nanomaterial in the methanolysis reaction of NaBH4, temperature, catalyst, substrate, and reusability experiments were carried out and kinetic calculations were obtained. Among the activation parameters of FeCo@PVP nanoparticles, turnover frequency, enthalpy, entropy and activation energy were calculated as 3858.9 min−1, 29.39 kJ/mol, −139.7 J/mol.K, and 31.93 kJ/mol, respectively. As a result of the reusability test of the obtained FeCo@PVP nanoparticles catalysts, which was carried out for 4 cycles, the catalytic activity was 77%. Catalytic activity results are given in comparison with the literature. In addition, the photocatalytic activity of FeCo@PVP NPs was evaluated against MB azo dye under solar light irradiation for 75 min and was found to be as 94%.

Controllable Synthesis, Polar Behavior and Photoelectric Properties of BiOCl Microplates

Bismuth oxychloride (BiOCl) square microplates were prepared via a facile hydrothermal method. The X-ray diffraction patterns of the samples reveal a tetragonal BiOCl phase, and the scanning electron microscopy images show plate-like structures with large lateral size of 3~6 μm and thickness in the range of 100~300 nm. The effects of surfactant, reaction temperature and duration on the morphology of BiOCl powders are systematically investigated. The polar behavior of a BiOCl single-crystalline microplate is examined by using piezoresponse force microscopy evidenced over 80 pm displacement under 40 V bias voltage. In addition, the photoelectric performance of the BiOCl microplates is evaluated by using electrochemical workstation with three-electrode system, and large photocurrent densities (over 0.5 μA/cm2) and fast photoresponse (0.7~1.1 s) are detected by applying both 365 nm monochromatic light and sunlight illumination. The surface potential changes of BiOCl microplate under different light condition, characterized by in-situ Kelvin probe force microscopy, further verify the separation ability of the photo-induced charge carriers. These findings would be beneficial for further design photocatalytic and piezocatalytic materials.

Synergistic photodegradation of methylene blue by Sm doped Fe2O3 photocatalyst under sunlight

• Fe 2 O 3 , Sm 2 O 3 and Sm doped Fe 2 O 3 photocatalysts synthesized via sol-gel route • Sm-doped material showed good surface area of 1327 cm 2 /g • The doped materials showed excellent photodegration of 99.8% • The higher efficiency of the catalyst is owing to efficient charge separation/transportation. The growing population led to an increase in water contamination, which urged researchers to develop an efficient, eco-friendly, and safe catalyst to remove these pollutants from water bodies. Herein the present study, the Sm-doped Fe 2 O 3 photocatalyst was developed through a low-cost and facile sol-gel route to degrade methylene blue (MB) under sunlight. Various characterizations of the photocatalyst were performed by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), photoluminescence (PL), and UV–vis spectrometry, current-voltage measurements (IV), and electrochemical impedance spectroscopy (EIS). The XRD confirmed the successful doping of Sm in Fe 2 O 3 lattices. Remarkably, the adsorption were 14%, 10%, 34%, photo-reduction efficiencies were 78.2%, 79.1%, 65.8%, while complete degradation of dyes were 91.2, 89.1 and 99.8% for Fe 3 O 3 , Sm 2 O 3 and Sm-doped Fe 2 O 3 , respectively, against methylene blue dye after 1.0 h under sunlight illumination. Moreover, the enhanced photocatalytic performance of the doped catalyst was found to be due to the structural variation, lower energy bandgap, hindered recombination, and the efficient charge carriers separation/transportation at the surface. The effective synergistic photocatalytic performance proved its potential in water remediation.

In situ confined growth of g-C3N4/pigment compound catalyst in porous diatomite for enhancing photocatalytic nicotine elimination and bacterial inactivation

Humans spend at least 70% of their time indoors, but indoor air pollution has received very little attention compared to outdoor pollution. Indoor air pollutants include inhalable particulate matter, volatile organic pollutants, and biological pollutants. In particular, nicotine in second-hand smoke and pathogenic microorganisms in the air are the most overlooked pollutants, which pose serious threats to human health. Here, low-cost inorganic pigments and diatomite have been selected to modify g-C3N4 to obtain five novel g-C3N4-based photocatalysts, which are intensely colored and show excellent nicotine degradation performance under both simulated sunlight and white LED illumination. Five g-C3N4-based photocatalytic textiles obtained by supporting the colored photocatalysts on low-melting-point skin–core composite polyester (LMPET) still exhibited outstanding photocatalytic degradation performance and cyclability in removing nicotine. Some of the photocatalytic textiles also displayed highly efficient bacterial inactivation towards E. coli and S. aureus under white LED illumination. Mechanistic research has revealed that the combination of inorganic pigments and diatomite effectively promotes the separation of photogenerated electrons and holes. Moreover, •O2-, 1O2, and •OH have been identified as the main active species in the colored photocatalyst systems. Notably, the colored photocatalysts may be used as dyes to make wall coverings, sofa covers, and so on, which could conceivably purify indoor air while playing a decorative role.

Defect-enriched red phosphorus nanosheets as efficient and stable photothermal absorber material for interfacial solar desalination

The development of efficient photothermal materials has gained increasing attention for solar thermal-energy conversion. A good photothermal material has a strong light-absorption property, low thermal conductivity, high wettability, and high solar-to-thermal conversion efficiency. In this study, we prepared uniform, sub-micron, and defect-rich red phosphorus (RP) nanosheets via a simple ball-milling method to demonstrate their efficient and durable solar steam generation properties. Three RPs of different sizes were prepared by controlling the milling time (0 h: RP0, 30 h: RP30, and 60 h: RP60). Notably, RP60 exhibited the smallest particle (lateral) size, nanosheet morphology, and defect-rich surface. Furthermore, RP60 exhibited the distinctive properties of a small band gap (1.44 eV), low thermal conductivity (0.07 W/m·K), and low heat capacity (0.66 J/g·K) with exceptional wettability. With simulated sunlight illumination (100 mW/cm2, 1 sun), the RP60 photothermal absorber demonstrated a high water evaporation rate of 1.34 kg/m2·h with a stable solar steam generation efficiency of 74.1 % for over 10 h. A one-dimensional water path and porous polyurethane support facilitated the water supply, large contact area, heat localization, and steam escape. By employing plasmonic resonance-heating silver nanoparticles on the RP60, we achieved a significantly improved solar steam generation efficiency of over 96.0 % and a water evaporation rate of 1.75 kg/m2·h. This study highlights the critical role of morphology, particle size, and defects control in improving the photothermal properties for efficient and durable interfacial seawater desalination.