Sunlight Irradiation Research Articles

FeOOH Quantum Dots Assembled MXene‐Decorated 3D Photothermal Evaporator for Synergy Application in Solar Evaporation and Fenton Degradation

AbstractSolar‐driven water evaporation is considered as the sustainable approach to alleviate freshwater resource crisis through direct use of solar energy. However, it is still challenging to achieve the multifunctional solar evaporators equipped with both high evaporation and purification performance to handle practical complex wastewater. Here, a simple and cost‐effective multifunctional 3D solar evaporator is prepared by alternately decorating the commercial sponge with FeOOH quantum dots (FQDs) supported MXene sheets composites and chitosan hydrogel coatings for enabling the solar water evaporation and organic wastewater photodegradation simultaneously. MXene composites allow the solar evaporator with excellent photothermal conversion performance, the hydrophilic chitosan hydrogel coated interconnecting skeleton structures of sponge serve as the mass transfer and water transport channels. The Fenton‐catalytic FQDs anchored on the MXene sheets surface accept the photo‐generated electrons of MXene sheets to induce the organic pollutant photo‐Fenton degradation reaction under sunlight irradiation. The resulting evaporator possesses both excellent water evaporation rate of 2.54 kg m−2 h−1 and high degradation efficiency (99.24% for methylene blue), coupled with durable salt‐resisting performance during long‐term seawater desalination (20 wt.% NaCl). This work provides a simple and feasible strategy for designing multifunctional solar evaporators to meet the potential application scenarios in practice.

Photoelectric activity evaluation of surface-loaded ferroferric oxide/titanium dioxide composite prepared from ilmenite

This work demonstrates a surface-loaded Fe3O4/TiO2 composite with the magnetic Fe3O4 deposited on the surface of anatase TiO2 nanocrystal which can be directly prepared from the ilmenite using the coprecipitation method. After the acidolysis treatment with the 95% dissolution rate, the ilmenite will be first transformed into H2TiO3 and FeCl2, and the photoactive anatase TiO2 nanocrystals are obtained from the calcined H2TiO3 at 500[Formula: see text]C. Then a surface-loaded Fe3O4/TiO2 composite TF is finally achieved by the coprecipitation method, which is carefully elaborated to balance the magnetism and photoactivity of Fe3O4/TiO2 composite by the optimal contents of Fe3O4 and TiO2. It is encouraging to note that Fe3O4/TiO2 composite TF shows a good comprehensive performance in serial photodegradation experiments of Rhodamine B. The degradation rate of Rhodamine B is more than 99% during 60 min under the irradiation of both xenon lamp and sunlight. During at least six cycles, the composite TF can show stable photocatalytic activity and good durability together with the recovery and recycling potentials by using an external magnet.

N‐ZrS3/p‐ZrOS Photoanodes with NiOOH/FeOOH Oxygen Evolution Catalysts for Photoelectrochemical Water Oxidation

AbstractPhotoelectrochemical water splitting offers a promising approach for carbon neutrality, but its commercial prospects are still hampered by a lack of efficient and stable photoelectrodes with earth‐abundant materials. Here, we report a strategy to construct an efficient photoanode with a coaxial nanobelt structure, comprising a buried‐ZrS3/ZrOS n−p junction, for photoelectrochemical water splitting. The p‐type ZrOS layer, formed on the surface of the n‐type ZrS3 nanobelt through a pulsed‐ozone‐treatment method, acts as a hole collection layer for hole extraction and a protective layer to shield the photoanode from photocorrosion. The resulting ZrS3/ZrOS photoanode exhibits light harvesting with good photo‐to‐current efficiencies across the whole visible region to over 650 nm. By further employing NiOOH/FeOOH as the oxygen evolution reaction cocatalyst, the ZrS3/ZrOS/NiOOH/FeOOH photoanode yields a photocurrent density of ~9.3 mA cm−2 at 1.23 V versus the reversible hydrogen electrode with an applied bias photon‐to‐current efficiency of ~3.2 % under simulated sunlight irradiation in an alkaline solution (pH=13.6). The conformal ZrOS layer enables ZrS3/ZrOS/NiOOH/FeOOH photoanode operation over 1000 hours in an alkaline solution without obvious performance degradation. This study, offering a promising approach to fabricate efficient and durable photoelectrodes with earth‐abundant materials, advances the frontiers of photoelectrochemical water splitting.

Scalable, Fast Light‐Responsive, and Excellent Color‐Retention Fiber‐Based Photochromic Wearables for Sustainable Photo‐Patterning and Information Security Encryption

AbstractFiber‐based photochromic wearables have attracted growing attention in sustainable photo‐patterning information displays, information security encryption, and optical data recording/storage. Molybdenum trioxide (MoO3) is one of the key photochromic materials that possesses good photochromic performance, nevertheless, it faces considerable challenges in preparing photochromic textiles with stable, scalable, and long color‐retention properties. In this work, a new kind of fiber‐based photochromic wearables is designed and developed by combining cotton fabric with a MoO3‐based self‐adhesive polymer network and long chain silyl group. The prepared photochromic wearable has exhibited excellent fatigue resistance and favorable reversibility (> 40 cycles), rapid light response (reach color saturation with a UV dose of 60 kJ m−2), outstanding color retention capability (> 90 days), and desirable biocompatibility (cell viability > 100%). In addition, the prepared photochromic textiles could maintain a fast light response and excellent color retention even after experiencing repeated washing (20 cycles). Moreover, the photo‐patterning photochromic wearables are verified by resisting the deterioration of acid solution, alkali solution, and sweat (pH 2.0–9.0) as well as keeping clear patterns under sunlight irradiation. As a demonstration of the application, fiber‐based photochromic wearables are made and employed for the sustainable applications of rewritable photo‐patterning and information security encryption.

Layer symmetry and irradiation dominate the oxidation capability of birnessite on biogenic isoprene

The climate-active gas isoprene (C5H8) is one of the most abundant biogenic volatile organic compounds (VOCs). Soil is one of the significant sinks for isoprene, yet the role played by the naturally abundant birnessite in the soil surface layer during the oxidation of isoprene remains largely unknown. This study investigates the reactions of isoprene with triclinic and hexagonal birnessite on the Earth's surface environments. Hexagonal birnessite exhibits a superior oxidation capacity than triclinic birnessite, rapidly oxidizing isoprene. The transformation of birnessite from triclinic to hexagonal increases the number of interlayer Mn(III) octahedra, which creates numerous sites for isoprene oxidation. In-situ DRIFTS and DFT calculations indicate that abundant electrophilic active species on the surface of hexagonal birnessite, such as interlayer Mn(III) octahedra and 1O2, oxidize isoprene by attacking conjugated double bonds. Furthermore, birnessite exhibits excellent photoelectric response and photothermal effects, enabling sunlight irradiation under natural conditions to accelerate the oxidation of isoprene by birnessite. The findings of this study elucidates the critical role of birnessite in the oxidation of isoprene and shed light on the fate of isoprene in soil minerals.

Sustainable photocatalytic hydrogen peroxide production over octonary high-entropy oxide

The direct utilization of solar energy for the artificial photosynthesis of hydrogen peroxide (H2O2) provides a reliable approach for producing this high-value green oxidant. Here we report on the utility of high-entropy oxide (HEO) semiconductor as an all-in-one photocatalyst for visible light-driven H2O2 production directly from H2O and atmospheric O2 without the need of any additional cocatalysts or sacrificial agents. This high-entropy photocatalyst contains eight earth-abundant metal elements (Ti/V/Cr/Nb/Mo/W/Al/Cu) homogeneously arranged within a single rutile phase, and the intrinsic chemical complexity along with the presence of a high density of oxygen vacancies endow high-entropy photocatalyst with distinct broadband light harvesting capability. An efficient H2O2 production rate with an apparent quantum yield of 38.8% at 550 nm can be achieved. The high-entropy photocatalyst can be readily assembled into floating artificial leaves for sustained on-site production of H2O2 from open water resources under natural sunlight irradiation.

Highly efficient reduction of Cr(VI) from industries sewage using novel biomass-driven carbon dots modified TiO2 under sunlight

Hexavalent chromium (Cr(VI)) pollution poses a significant global environmental challenge, with current photocatalysts exhibiting limited efficiencies under natural sunlight, especially in neutral to alkaline conditions or at high Cr(VI) concentrations. In this study, amine-rich biomass-derived carbon dots (CDs) were synthesized from peanut shells and ethylenediamine via a hydrothermal method, combined with titanium dioxide (TiO2) to form a composite with a narrower band gap. This enhanced the electrostatic interactions with Cr(VI), thus improving photocatalytic performance. The composite (1 % CDs) effectively reduced 50 mg/L of Cr(VI) within 60 min under sunlight irradiation, demonstrating stable performance across various pH levels (3, 5, 7, and 9) and Cr(VI) concentrations (10 to 60 mg/L). Even after five cycles, the reduction efficiency remained high at 96.83 %. The composite also achieved reduction rates of 90.09 % and 89.01 % for domestic and electroplating wastewater, respectively, while exhibiting antibacterial properties. Free-radical scavenging experiments confirmed that electrons and holes were the primary active species driving the reduction. This work highlights the potential of the composites for efficient and stable Cr(VI) reduction in real-world water treatment applications.

Shining light on broad-spectrum responded NaYF4:Yb,Er,Tm@Bi@BiOI: Understanding the enhanced photodegradation performance of bisphenol A and mechanisms

This work reported a novel ternary heterogeneous photocatalyst NaYF4:Yb,Er,Tm@Bi@BiOI (NBEG-6h). NBEG-6h exhibits broad-spectrum absorption from ultraviolet to near-infrared. The elimination efficiency of BPA by NBEG-6h under simulated sunlight and near-infrared light irradiation was 88% (24 min) and 93.9% (160 min), respectively. It also has the universality of degrading various pollutants, good reusability and stability. The exceptional photocatalytic activity can be attributed to the absorption of near-infrared light by NaYF4:Yb,Er,Tm, which improves the total efficiency of sunlight utilization. The localized surface plasmon resonance effect of Bi nanoparticles enhances the light absorption performance of the heterostructure. Furthermore, combining Bi and BiOI accelerates carrier migration and improves the separation efficiency of photogenerated electron-hole pairs. h+, ·O2− and 1O2 play the pivotal roles during the photocatalytic process. This research offers new insights into the design, development, and mechanism understanding of full-spectrum-driven heterostructure photocatalysts. It provides an environmentally sustainable approach to the treatment of harmful organic pollutants.

Thermal reflectance of fabric in color temperature spectral domain

PurposeThis study aims to explore the thermal reflectance of fabrics under sunlight or other thermal radiation sources at various color temperatures.Design/methodology/approachThis study analyzed the spectral distribution of sunlight at different solar altitude angles as well as the spectral distribution characteristics of other light and thermal radiation sources, pointing out that their color temperatures can be used to identify their spectral distribution domains. Reflectance, transmittance, absorptance and color temperature domain reflectance of 35 different fibers and color fabrics were tested in a wide spectral range. The different behavior of these optical parameters in the segmented spectrum is discussed. The temperature rise tests demonstrate that the reflectance corresponding to the color temperature of the radiation sources is highly correlated with the temperature rise results.FindingsThe reflectance in the color temperature domain shows a strong correlation with the radiation source at same color temperature. The correlation coefficients for the 6,000 K xenon lamp test are −0.96 and −0.90 in two groups, and for the 3,200 K tungsten iodine lamp test are −0.87 and −0.90 as well.Originality/valueThe concept of fabric thermal reflectance in the color temperature domain was first introduced to match different thermal radiation sources. Validation of temperature rise is conducted through a self-constructed tester with unidirectional adiabatic heating. This new discovery could serve as a basis for developing functional fabric or clothing, such as sun-proof clothing, fire protection clothing, etc.

Enhanced photocatalytic performance of (Mg, Cu) Dual-Doped ZnS nanosheets for Solar-Driven water treatment and embedded with PVA polymer membrane for reusability

Photocatalysis uses semiconductor materials to solar energy effectively purify to water by eliminating pollutants. Organic Dye degradation serves as a standard to assess the photocatalytic effects of the materials. In this study Mg, Cu dual-doped ZnS nanosheets were synthesized using the coprecipitation method. The impact of the concentration on the structural, morphology, optical, and degradation efficiency was investigated with XRD, XPS, TEM with EDAX, and UV spectroscopy. The pure ZnS and Zn0.98-xCu0.02MgxS (x = 0, 0.01, 0.02) (ZCM1, ZCM2, ZCM3, and ZCM4) nanosheets, exhibited cubic structure with high phase purity. The average crystalline size was calculated as 1.66, 1.60, 1.45, and 1.47 nm for the ZCM1, ZCM2, ZCM3, and ZCM4 nanosheets, respectively. TEM analysis revealed the presence of crumpled nanosheets. The bandgap of the ZCM1, ZCM2, ZCM3, and ZCM4 nanosheets were 3.99, 3.78, 4.03, and 4.09 eV respectively. This study investigated the photocatalytic activity of crystal violet dye when exposed to natural sunlight irradiation. Notably, ZCM3 nanosheets exhibited a high degradation rate of 99 % over 120 min under sunlight. Furthermore, the proposed dye degradation mechanism, effect of dosage, effect of dye variation, reusability, scavenging activity, and hemolytic activity were comprehensively discussed. The nanosheets embedded with the Polyvinyl alcohol (PVA) polymer membrane for reusability.

N-Type Nanocomposite Films Combining SWCNTs, Bi2Te3 Nanoplates, and Cationic Surfactant for Pn-Junction Thermoelectric Generators with Self-Generated Temperature Gradient Under Uniform Sunlight Irradiation

N-Type Nanocomposite Films Combining SWCNTs, Bi2Te3 Nanoplates, and Cationic Surfactant for Pn-Junction Thermoelectric Generators with Self-Generated Temperature Gradient Under Uniform Sunlight Irradiation

SiO2/polydopamine photothermal superhydrophobic coating with good anti-icing performance

The icing phenomenon has become a safety hazard for the normal operation of equipment. In this work, we report a strategy for simply obtaining photothermal anti-icing coatings by spraying acrylic resin, polydimethylsiloxane and polydopamine modified SiO2 particles on a steel plate substrate. The prepared icephobic AR/PDMS/SiO2@PDA composite coating not only has excellent superhydrophobicity (WCA = 162°). It also shows good anti- and de-icing performances. The superhydrophobic surface was able to delay freezing for 614 s at −20°C, and the ice adhesion of its surface was 54 kPa. In addition, PDA-modified SiO2 particles endow the coating with photothermal properties. Under the irradiation of simulated sunlight, the photothermal coating rapidly reached 61°C within 3 min, and the ice droplets completely melted in 155 s. Besides, it's able to withstand a wide range of chemical attacks and mechanical impacts. After 15 icing-de-icing cycles and 40 sandpaper abrasions cycles test, the prepared coatings can still maintain remarkable ice-removal performance, demonstrating excellent mechanical robustness and stability in harsh environments.

Remarkable reactions of doped and Co-doped Co3O4 thin films synthesized by spray pyrolysis technique for enhanced catalytic degradation of methylene blue dye under sun light irradiation

Remarkable reactions of doped and Co-doped Co3O4 thin films synthesized by spray pyrolysis technique for enhanced catalytic degradation of methylene blue dye under sun light irradiation

Optimization of Photocatalytic Degradation of Rhodamine B and Indigo Carmine Dyes Using Eco‐Friendly Kaolinite‐Silver Oxide Quantum Dots Nanocomposite Under Sunlight Irradiation

ABSTRACTIn this work, we present a simple method for the pyrofabrication of a new kaolinite‐ silver oxide quantum dots nanocomposite (Kao‐Ag2O/QDs) that is used for the degradation of rhodamine B (RhB) and indigo carmine (IC) dyes. A homogenous combination of kaolinite and silver nitrate was sintered up to 350 °C to create the extremely effective photocatalyst (Kao‐Ag2O/QDs). Various analytical techniques were employed to characterize the Kao‐Ag2O/QDs photocatalyst such as XRD, FTIR, XPS, SEM–EDX, TEM, DTA/TGA, ZP, BET, and UV–Vis DRS. The degradation of RhB and IC dyes through the photocatalyst was carried out in aqueous solutions utilizing several pH dye solutions and sustainable solar energy in atmosphere conditions. The nanocomposite that was prepared had shown an enhanced specific surface area of 53.3005 m2/g, a pore size of 8.1197 nm, and a total pore volume of 0.216 cm3/g. It also displayed an optical band gap energy of 2.9 eV. The study creates that employing the ideal dose of 2000 and 1500 mg/L of the Kao‐Ag2O/QDs photocatalyst at neutral conditions (pH = 7) resulted a maximum degradation effectiveness of RhB and IC of 91.06 and 93.46% after 90 min, respectively. RhB and IC dyes degradation followed Langmuir first‐order kinetics with a rate constant of 0.0217 and 0.0216 min−1 at pH = 7, respectively. The photocatalytic degradation activity for RhB dye is based on hydroxyl radicals (˙OH) and superoxide radicals (˙O2−), while the mechanism of IC removal is based on superoxide radicals (˙O2−), as revealed by scavenger‐based radical trapping studies. A triple reusability study found that the Kao‐Ag2O photocatalyst is highly stable with degradation efficiencies of RhB and IC dyes from the initial 91.09 to 90.04, 88.54, and 86.27% and from the initial 93.46 to 92.8, 91.4 and 89.32%, respectively. The optimal situations for the parameters were identified by the Box–Behnken design (BBD), which was well matched with photocatalytic degradation tests.

Visible Light Driven Defect Mediated Photocatalytic Activity of Spray Pyrolyzed Ga and Al Doped ZnO Thin Film Electrodes

AbstractGa and Al doped ZnO thin film electrodes are spray deposited and explored for photocatalytic deterioration of methylene blue dye. X‐ray diffraction unveils both films to have highly textured growth along the (002) plane. The surface morphology is found to have near spherical and distorted rectangular particles for Ga and Al dopants, respectively. Photoluminescence emission study reveals that both films have visible light emissions in the violet, blue, and green regions due to oxygen vacancy defects. The deposited films exhibit a reasonably higher transmittance of 89 and 77 % with mobility of 30.5 and 29.6 cm2/Vs for Ga and Al doped ZnO, respectively. Cyclic test and photo‐corrosion studies performed for selected samples were indicating significant stability. Based on these findings the electrodes are explored for the photocatalytic degradation of methylene blue dye and are found to have significant efficiency upon LED and sunlight irradiation.

Evaluating the Photocatalytic Activity of Green Synthesized Iron Oxide Nanoparticles

Water pollution from dyes is a major environmental challenge, demanding advanced materials for efficient degradation. In this study, we synthesized iron oxide nanoparticles (IONPs) using an aqueous extract of Senegalia catechu leaves and evaluated their photocatalytic activity in methylene blue (MB) dye degradation under sunlight irradiation. The IONPs were characterized by UV-visible spectroscopy (UV–vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). XRD pattern showed a highly crystalline structure with an average crystallite size of 34.7 nm, while SEM images revealed predominantly spherical particles with uneven surface texture. Photocatalytic efficiency exceeded 80% MB dye degradation after 120 min of sunlight exposure. Optimization of catalyst dose, pH, dye concentration, and other parameters is essential for maximizing degradation efficiency. The IONPs demonstrated reusability over four degradation cycles, retaining effective photocatalytic performance. This study underscores the potential of green-synthesized IONPs as eco-friendly photocatalysts for wastewater treatment and environmental remediation.

Synthesis of gold nanoparticles using soybean byproducts: applications in catalysis

AbstractThis study demonstrates the feasibility of extracting lecithin from oil industry byproducts in an eco‐friendly manner, with minimal use of water and without harmful chemicals. Liposomes can be generated directly from this extracted lecithin, enhancing the value of these byproducts and enabling the production of catalytic gold nanoparticles (AuNPs). Thin‐layer chromatography of the extracted lecithin revealed a phospholipid composition primarily consisting of phosphatidylethanolamine and phosphatidylcholine, and surface tension studies demonstrated similar behavior between the extracted and commercial lecithin. Liposome formation using sustainable lecithin (LPn) resulted in structures that were stable for at least 10 days, exhibiting a low polydispersity index (0.395) and uniform size (approximately 214 ± 7 nm). Gold nanoparticles were synthesized successfully in LPn loaded with [HAuCl4] by using different photoreduction methods: ultraviolet (UV) lamp, pulsed laser 355 nm, and sunlight irradiation. The AuNPs exhibited characteristic sizes (ranging from 5.03 to 6.78 nm) and optical properties typical of nanoparticles, including a distinct surface plasmon resonance. As a proof of concept, we also demonstrated that the synthesized AuNPs exhibited catalytic activity in UV‐induced cis‐trans isomerization reactions. Overall, the study highlights the potential of sustainable soy lecithin extraction for diverse applications, including nanoparticle synthesis and catalysis.

Pea Pod–Derived Biochar–Zeolitic Imidazolate Framework Composite for the Photocatalytic Degradation of Two Organic Dyes Crystal Violet and Victoria Blue

ABSTRACTThe rapid increase of water pollution globally is a vital environmental concern that requires the immediate attention of researchers to find new innovative ways to remove unwanted environmental pollutants from our water sources. With the advances in the field of sustainable engineering, there is a high demand for the effective utilization of biomass resources for the removal of aqueous environmental contaminants. Biochar is carbon carbon‐enriched substance obtained by biomass pyrolysis; it is inexpensive and has received wide attention in the field of wastewater treatment. Herein, we describe the synthesis of pea pod (PO) biochar‐reinforced zeolitic imidazolate framework (ZIF‐8) nanocomposite (PO@ZIF‐8) through the in situ precipitation of ZIF‐8 onto the biochar surface. The crystal growth, morphology, chemical composition, and optical characteristics of fabricated PO@ZIF‐8 nanocomposite were scrutinized through PXRD, SEM, TEM, UV‐DRS, PL, and XPS analysis. The dodecahedral‐shaped PO@ZIF‐8 particles have an average size between 140 and 160 nm. The biochar‐reinforced ZIF‐8 nanocomposite showed significantly higher photocatalytic activity than the pure ZIF‐8 for the degradation of two commonly found organic dyes crystal violet (CV) and Victoria Blue (VB) in the presence of direct sunlight irradiation. The PO@ZIF‐8 nanocomposite showed the highest degradation efficiency of ~87% and ~80% within 50 min of irradiation time at a catalyst dosage of 20 mg for 30 ppm CV and VB dye solutions at pH 8. First‐order kinetics were obeyed during the photodegradation with 0.041 and 0.030 min−1 as the constant of degradation for the removal of CV and VB. The radical scavenger experiment and the photoluminescence analysis confirm the active participation of ·OH radical in the degradation of both dyes. LC–MS and TOC analysis was also performed to determine the degradation products and for evaluation of the degradation progress. Moreover, the synthesized PO@ZIF‐8 composite also exhibit good stability till the fourth cycle with high degradation efficiency thus making it a good choice of catalyst in the field of environmental decontamination.

A Photo-Assisted Zinc-Air Battery with MoS2/Oxygen Vacancies Rich TiO2 Heterojunction Photocathode.

Converting solar energy into electrochemical energy is a sustainable strategy, but the design of photo-assisted zinc-air battery (ZAB) with efficient utilization of sunlight faces huge challenges. Herein, a photo-assisted ZAB of a three-electrode system using MoS2/oxygen vacancies-rich TiO2 heterojunction as charge cathode and Fe, N-doped carbon matrix (FeNC) as discharge cathode is constructed, where MoS2 is chosen as solar light-responsive catalytic material and TiO2 acts as electron transport layer and hole blocking layer, arising from a train of thought for efficient charging under sunlight irradiation and light-independent discharging. The introduction of oxygen vacancies in TiO2 facilitates the temporary trapping of carriers and triggers rapid carrier transfer at the interface of the heterojunction, which hinders the recombination of photogenerated holes, thereby facilitating their further participation in the oxygen evolution reaction. Moreover, FeNC exhibits superior oxygen reduction reaction performance due to strong d-π interactions. As a result, the well-built ZABs deliver a low charge voltage (0.71 V) under illumination at 0.1 mA cm-2, and a high power density (167.6mW cm-2) in dark. This work paves a special way for the development of ZABs by directly harvesting solar energy in charging and efficiently discharging regardless of lighting conditions.

Photocatalytic Degradation of Phenol using Copper-Doped Graphitic Carbon Nitride under Fluorescent and Sunlight Irradiation

Photocatalytic Degradation of Phenol using Copper-Doped Graphitic Carbon Nitride under Fluorescent and Sunlight Irradiation