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Artificial photosynthesis holds immense promise for sustainable clean energy harvesting, with recent strides in material engineering with the earth abundant elements enabling efficient utilization of the visible solar spectrum for photoelectrochemical catalytic water splitting. Here, we have investigated the impact of substitutional Cu doping at all three cation sites in Ba2YNbO6 (BYN) using density functional theory calculations at the Heyd-Scuseria-Ernzerhof-06 level. One of the key findings is that the defect formation energy follows the hierarchy Nb > Ba > Y. The presence of an oxygen vacancy (OV) enhances the co-solubility of Cu substitution of Nb, particularly when placed outside the CuO6 unit, while it has a contrary effect for Y substitution. Cu replacement reduces the bandgap as Nb > Y ≫ Ba vis-à-vis pure BYN, while extending it into the visible part of the solar spectrum for Nb and Y replacement cases, albeit with OV causing a slight blue shift to them, without reducing the oxidation state of Cu due to strong charge-delocalization. Cu doping at Y and Nb sites retains the direct band transition character of BYN, a feature removed by OV. While all the bare Cu doped systems exhibit formation of a weak electron polaron, the placement of OV tends to annihilate this except for the system comprising first nearest neighbor placement of an OV relative to the Cu substitution at an Nb site. Notably, Cu doping at the Nb site significantly enhances optical activity, particularly ∼2.0–2.5 eV, resulting in promising candidates for photoelectrochemical catalysts. [ABSTRACT FROM AUTHOR]

In recent years, the exploration of solar absorbers has grown in favor due to the scarcity of energy. Here, we propose an absorber with an array of a circular ring surrounding disk (RSD) for solar energy capture. The novel structure keeps above 93.5% absorption with an average absorption of 96.95% in wavelengths from 300 to 4000 nm. Meanwhile, the proposed absorber is advantageous in that the structure is generalizable to other metals and dielectric materials. Furthermore, the data results show that the absorber has polarization-independent properties as well as maintaining >90% absorption in the considered wavelength range up to an incidence angle of 52° and >95% absorption at large process tolerances. Finally, the excellent absorption under the AM1.5 solar spectrum demonstrates the RSD absorber's ability to capture solar energy. These results show the potential of the absorber for applications in electromagnetic invisibility cloaking, thermal emitters, and solar energy capture and conversion. [ABSTRACT FROM AUTHOR]

In this study, low-cost laser marker ablation of vanadium-coated glass was adopted to prepare self-cleaning, anti-reflective, and anti-fog micro-nano structures on its surface. The surface had a hierarchical micro-nano structure composed of a quasi-periodic microstructure and ∼100 nm-sized worm-like clusters interspersed with dispersed nanoparticles. The solar spectrum (AM 1.5) weighted average transmission of treated glass was enhanced by 3.87% over control glass in the wavelength range of 400–1100 nm. Importantly, the water contact angle of the laser-treated samples achieved and maintained 0° for a duration of 25 days, and the laser-treated samples achieved and maintained excellent anti-fog performance for 150 days. The antifog performance degraded substantially afterward, though was still noticeable compared to the reference even after 428 days of storage in the laboratory. Furthermore, co-achievement of exceptional self-cleaning anti-fog performance and broadband transmission enhancement through laser treatment of glass has rarely been previously reported. [ABSTRACT FROM AUTHOR]

Taking into account the electron-rich and visible light response of thiophene, first-principles calculations have been carried out to explore the photocatalytic activity of donor–acceptor polymers incorporating thiophene and boron. Honeycomb-kagome boron–thiophene (BTP) polymers with varying numbers of thiophene units and fixed B center atoms are direct bandgap semiconductors with tunable bandgaps ranging from 2.41 to 1.88 eV and show high absorption coefficients under the ultraviolet and visible regions of the solar spectrum. Fine-tuning the band edges of the BTP polymer is efficiently achieved by adjusting the pore size through the manipulation of thiophene units between the B centers. This manipulation, achieved without excessive chemical functionalization, facilitates the generation of an appropriate quantity of photoexcited electrons and/or holes to straddle the redox potential of the water. Our study demonstrates that two units between B centers of thiophene in BTP polymers enable overall photocatalytic water splitting, whereas BTP polymers with larger pores solely promote photocatalytic hydrogen reduction. Moreover, the thermodynamics of hydrogen and oxygen reduction reactions either proceed spontaneously or need small additional external biases. Our findings provide the rationale for designing metal-free and single-material polymer photocatalysts based on thiophene, specifically for achieving efficient overall water splitting. [ABSTRACT FROM AUTHOR]

VO2-based thermochromic coatings have gained much attention in temperature-adaptive smart windows, and constructing multilayer film structures is the main way to obtain high thermochromic performances. Based on the self-developed objective-orientated automatic optimization code, the present research realized customized designs of thermochromic multilayer coatings composed of VO2, TiO2, and SiO2 from the objectives of visible luminance (Tlum) and solar light modulation (ΔTsol). The TiO2/VO2/s, VO2/TiO2/s, TiO2/VO2/TiO2/s, and SiO2/TiO2/VO2/TiO2/s (s denotes substrate) multilayer film systems were then prepared by magnetron sputtering and vacuum controllable heating, with their structures, insulator-metallic transition, and thermochromic properties being carefully studied. The result showed that the best trade-off between high Tlum and high ΔTsol was achieved for these film assemblies, and solar light modulation was mainly limited at the near-IR wavelength region of the solar spectrum, with the difference between cool- and hot-state Tlum being greatly reduced. In the case of the four-layer SiO2/TiO2/VO2/TiO2/s, very high average Tlum (60%) and high ΔTsol (14%) were obtained. A 100 × 100 mm2 of the SiO2/TiO2/VO2/TiO2/s was also prepared, and it showed an obvious temperature adjustment, and the service life can last for 14 years under normal weather conditions. Not limited to the prepared multilayer film systems, the methodology used here is also suitable for the fast development of other multilayer film systems. [ABSTRACT FROM AUTHOR]

A set of narrow bandgap conjugated polymers was prepared, using cyclopentadithiophene (CDT) donor units coupled with benzothiadiazole (BT) acceptor units substituted with either no fluorine atoms (A1), one fluorine atom (A2) or two fluorine atoms (A3), using the Stille cross coupling reaction. The addition of two electron‐withdrawing fluorine atoms to the BT units was observed to deepen the HOMO energy level of the resulting copolymer, while only slightly affecting the LUMO level, as evidenced by cyclic voltammetry examination. The alternating copolymers (CDT‐A1, CDT‐A2 and CDT‐A3) possess small optical bandgaps of 1.37, 1.43 and 1.51 eV (which should efficiently harvest a broad part of the solar spectrum), and a moderate HOMO level of −5.00, −5.05 and −5.12 eV, respectively. CDT‐A3 displayed the highest optical/electrochemical‐bandgap and the deepest HOMO level, a consequence of the addition of the fluorine atoms on the BT moieties. Inclusion of two fluorine atoms resulted in sharper X‐ray diffraction peaks in the CDT‐A3 copolymer with respect to its analogues CDT‐A1 and CDT‐A2 copolymer indicating a greater crystallinity. These findings clearly demonstrate that fluorination of BT units is an effective approach for adjusting the energy levels and optical properties of BT‐based materials for use in organic solar cells devices as well as for other applications. [ABSTRACT FROM AUTHOR]

Reflective and heat insulation coatings are new types of materials coated on constructions. However, their applications are limited by the undesired insulation effect resulting from the poor reflectance in the solar spectrum of the coating film. In this study, a reflective and heat insulation coating is successfully developed by combining titanium dioxide@polyacrylate (TiO2@PA) hybrid latex with a core‐shell structure and an insulation filler of bionic potassium titanate whisker (PTW). The TiO2 nanoparticles are distributed homogeneously in the polymer matrix due to the polymer‐encapsulated TiO2 structure, achieving a total solar reflectance (TSR) of 71.0%. Notably, the as‐prepared reflective and heat insulation coating films exhibit excellent TSR of 86.0% enabled by TiO2@PA latex and PTW, attributed to the synergistic combination of TiO2@PA and PTW with high TSR. The temperature inside the room coated with the reflective and insulation coatings on the roof is 16.6°C lower than that of the uncoated one, while 20 wt% PTW is introduced into the coating formulation. The resulting reflective and heat insulation coatings are attractive for the fields of passive cooling such as building energy conservation, automotive body, and so on, endowing people with a comfortable life, especially in the hot summer. [ABSTRACT FROM AUTHOR]

• The SOlar-Terrestrial Habitability Explorer (SOTHE) will carry 4 instruments conducting the first-ever simultaneous integrated spectra of the Sun and the Earth. SOTHE will explore the habitability of the Sun-Earth system and provide a unique baseline for habitable exoplanets exploration. Among more than 5000 exoplanets discovered up to now, around 60 are believed to be potentially habitable. The Sun-Earth system provides a unique example based on which detailed insights into the properties, formation, evolution, and thus habitability of exoplanets could be gained. However, simultaneous observation of the Sun as a star and the Earth as an exoplanet has been rare. In this paper, we introduce the SOlar-Terrestrial Habitability Explorer (SOTHE) to be deployed to the Sun-Earth L1 point. SOTHE will carry a science payload comprising four instruments to obtain the integrated spectra of the whole solar disk and the whole sunlit Earth at the same time, together with images of the Earth at 11 unique passbands from UV to NIR and the local plasma and magnetic field parameters at the L1 point. The core scientific goal of SOTHE is to understand key characteristics related to the habitability of the Sun-Earth system and provide a unique baseline for exploring habitable exoplanets, especially Earth-like planets around Sun-like stars. [ABSTRACT FROM AUTHOR]

Radiative transfer models are of prime importance in quantifying the earth-atmosphere energy budget. A radiative transfer model based on the Geant4 Monte Carlo toolkit was developed. This model is able to perform calculations of the spectral atmospheric transmittance, surface solar irradiance, as well as the Top of the Atmosphere (TOA) reflected irradiance over the spectral range from 280 nm to 3000 nm. Through this study, the Geant4 toolkit was used to study the effect of rural aerosols concentration on different radiative characteristics. Geant4 radiative calculations in the presence and absence of aerosols were compared to that of DISORT code. For both surface and Top of the atmosphere simulations, good agreement was observed between the two models. Specifically, under atmospheric visibility conditions of 23 km, the mean relative difference between Geant4 and DISORT code was found to be less than 2.46 % for Global irradiance calculations and less than 7.9 % for TOA reflected irradiance. A comparative analysis between the measured total global irradiance in Adrar city and the irradiance estimated by Geant4 demonstrated the general effectiveness of Geant4, with a coefficient of determination of 0.991 and a Mean Absolute Percentage Error (MAPE) of 5.851 %. [ABSTRACT FROM AUTHOR]

Photoreforming of polyethylene terephthalate (PET) to H2 is practically attractive strategy for upgrading waste plastics. The major challenge is to utilize the infrared energy in the solar spectrum to improve the efficiency for photoreforming of PET to H2. Herein, through the ingenious integration of tungsten phosphide nanoparticles and tungsten single atoms (WP/W SAs) with carbon nitride (g‐C3N4), the constructed hybrid inherits both the desirable properties and structural merits of the respective building blocks. Specifically, the photothermal effect of WP/W SAs couples with the "heat isolator" role of g‐C3N4 due to its low thermal conductivity, thereby forming localized high‐temperature regions, reducing the activation energy and improving the kinetics in the photoreforming of PET to H2. Additionally, the green pretreatment of PET using alkali‐free hydrothermal strategy is reported, achieving direct separation of the ethylene glycol and terephthalic acid. This work not only provides an alkali‐free hydrothermal pretreatment for PET, but also integrates the photothermal effect with the thermal insulation and opens a new avenue for harnessing solar energy into to convert plastics into H2. [ABSTRACT FROM AUTHOR]

Enabling high‐efficiency solar thermal conversion (STC) at catalytic active site is critical but challenging for harnessing solar energy to boost catalytic reactions. Herein, we report the direct integration of full‐spectrum STC and high electrocatalytic oxygen evolution activity by fabricating a hierarchical nanocage architecture composed of graphene‐encapsulated CoNi nanoparticle. This catalyst exhibits a near‐complete 98 % absorptivity of solar spectrum and a high STC efficiency of 97 %, which is superior than previous solar thermal catalytic materials. It delivers a remarkable potential decrease of over 240 mV at various current densities for electrocatalytic oxygen evolution under solar illumination, which is practically unachievable via traditionally heating the system. The high‐efficiency STC is enabled by a synergy between the regulated electronic structure of graphene via CoNi‐carbon interaction and the multiple absorption of lights by the light‐trapping nanocage. Theoretical calculations suggest that high temperature‐induced vibrational free energy gain promotes the potential‐limiting *O to *OOH step, which decreases the overpotential for oxygen evolution. [ABSTRACT FROM AUTHOR]

Dye‐sensitized photoelectrochemical cells can enable the production of molecules currently accessible through energetically demanding syntheses. Copper(I)‐based dyes represent electronically tunable charge transfer and separation systems. Herein, we report a Cu(I)‐bisdiimine donor‐chromophore‐acceptor dye with an absorbance in the visible part of the solar spectrum composed of a phenothiazine electron donor, and dipyrido[3,2‐a:2′,3′‐c]phenazine electron acceptor. This complex is incorporated onto a zinc oxide nanowire semiconductor surface effectively forming a photoanode that is characterized spectroscopically and electrochemically. We investigate the photo‐oxidation of hydroquinone, and the photosensitization of 2,2,6,6‐tetramethylpiperidine‐1‐oxyl and N‐hydroxyphthalimide for the oxidation of furfuryl alcohol to furfuraldehyde, resulting in near quantitative conversions, with poor selectivity to the alcohol. [ABSTRACT FROM AUTHOR]

The accurate measurement of high-resolution solar spectral irradiance (SSI) and its variations at the top of the atmosphere is crucial for solar physics, the Earth's climate, and the in-orbit calibration of optical satellites. However, existing space-based solar spectral irradiance instruments achieve high-precision SSI measurements at the cost of spectral resolution, which falls short of meeting the requirements for identifying fine solar spectral features. Therefore, this paper proposes a new method for reconstructing high-resolution solar spectral irradiance based on a residual channel attention network. This method considers the stability of SSI spectral features and employs residual channel attention blocks to enhance the expression ability of key features, achieving the high-accuracy reconstruction of spectral features. Additionally, to address the issue of excessively large output features from the residual channel attention blocks, a scaling coefficient adjustment network block is introduced to achieve the high-accuracy reconstruction of spectral absolute values. Finally, the proposed method is validated using the measured SSI dataset from SCIAMACHY on Envisat-1 and the simulated dataset from TSIS-1 SIM. The validation results show that, compared to existing scaling coefficient adjustment algorithms, the proposed method achieves single-spectrum super-resolution reconstruction without relying on external data, with a Mean Absolute Percentage Error (MAPE) of 0.0302% for the reconstructed spectra based on the dataset. The proposed method achieves higher-resolution reconstruction results while ensuring the accuracy of SSI. [ABSTRACT FROM AUTHOR]

Spectroscopic analyses of young late-type stars suffer from systematic inaccuracies, typically underestimating metallicities but overestimating abundances of certain elements including oxygen and barium. Effects are stronger in younger and cooler stars, and recent evidence specifically indicates a connection to the level of chromospheric activity. We present here a two-component spectroscopic model representing a non-magnetic baseline plus a magnetic spot, and analyse the resulting synthetic spectra of young solar analogues using a standard spectroscopic technique. For a moderately active star with solar parameters and chromospheric activity index |$\log R_\text{HK}^{\prime }= -4.3$| (⁠|$\sim 100$|  Myr), we predict that |$\left[\textrm {Fe/H}\right]$| is underestimated by 0.06 dex while |$v_\textrm {mic}$| is overestimated by 0.2 km s |$^{-1}$|⁠ ; for higher activity levels we predict effects as large as 0.2 dex and 0.7 km s |$^{-1}$|⁠. Predictions are in agreement with literature data on solar twins, and indicate that the model is a plausible explanation to the observed effects. The model is simple enough that it can be included in spectroscopic packages with only changes to the underlying spectrum synthesis modules, if a |$\log R_\text{HK}^{\prime }$| value is provided. [ABSTRACT FROM AUTHOR]

Water has been detected in lunar regolith, with multiple sources identified through the analysis of individual grains. However, the primary origin of water in the bulk lunar regolith remains uncertain. This study presents spectroscopic analyses of water content in sealed Chang'e-5 samples. These samples were sieved into various size fractions (bulk, <45 μm, and 45–355 μm) inside a glovebox filled with high-purity nitrogen. Results indicate a higher water content in the fine fractions (∼87 ± 11.9 ppm) than in bulk soil (∼37 ± 4.8 ppm) and coarse fractions (∼11 ± 1.5 ppm). This suggests that water is predominantly concentrated in the outermost rims of the regolith grains, and thus exhibits dependence on the surface volume ratio (also known as surface correlation), indicating solar wind is a primary source of lunar surface water. Laboratory, in-situ , and orbital results bridge sample analysis and remote sensing, offering a cohesive understanding of lunar surface water characteristics as represented by Chang'e-5. The discovery provides statistical evidence for the origin of water in lunar soil and can be considered representative of the lunar surface conditions. The water enrichment of the finest fraction suggests the feasibility of employing size sorting of lunar soils as a potential technological approach for water resource extraction in future lunar research stations. [ABSTRACT FROM AUTHOR]

Windows through heat exchange play a vital role in energy saving for realizing a net‐zero carbon emission society. Dual‐band electrochromic (EC) smart windows by dynamically regulate visible (VIS) and near‐infrared (NIR) light are necessary for improving both building energy efficiency and habitant comfort. However, the rational design of high‐performance electrochromic devices (ECDs) suffers sluggish EC response due to the slow ion transport. In this work, a locally dissociated Li+ concept is proposed to construct a solid‐state polymer electrolyte (SPE) with ultrafast Li+ transport. The succinonitrile (SN) is employed to loosen the Li+‐anion pair and the crystallographic C─O chain in the poly(ethylene glycol) methyl ether methacrylate (PEGMA) electrolyte by its strong solvation capability. The as‐prepared SPE shows a high ionic conductivity of 6.48 mS cm−1 at 30 °C and a high transmittance of >90%. The SPE‐based EC smart windows exhibited a fast switching speed (3.0/3.2 s for coloration/bleaching), a high coloration efficiency (CE) of 373.8 cm2 C−1, and a high optical modulation in the full solar spectrum (85%, 70%, 43% at 673, 1200, and 1600 nm, respectively). Finally, the SPE‐based EC smart windows shows three working modes with a temperature regulation range of 19.1 °C, exhibiting great potential in practical application. [ABSTRACT FROM AUTHOR]

The article is devoted to the significantly underestimated contribution of radiation from the young Sun to the formation of physical conditions on the early Earth. A new view on the faint young Sun paradox is presented: the main role in solving the paradox is given to the impact of the increased activity of the young Sun on the Earth's atmosphere. The role of planetary organic films is considered as a climate-forming factor involved in resolving the faint young Sun paradox. The spectrum of radiation of the young Sun and the paradox of the discrepancy between the chlorophyll absorption spectrum and the spectrum of solar radiation are discussed, and also indicated a possible connection between the faint young Sun paradox and the origin and evolution of photosynthesis on Earth. [ABSTRACT FROM AUTHOR]

Both renewable energy and fresh water inputs are required to develop sustainable green hydrogen. However, there is still a lack of an integrated system generating hydrogen cleanly. Therefore, this study aims to develop a full spectrum solar energy-driven system to co-generate fresh water and hydrogen. The seawater desalination and proton exchange membrane (PEM) electrolysis are introduced into a Ag@SiO 2 nanofluid-filtered photovoltaic/thermal (PV/T) system. The desalinated seawater can be directly used for the electrolysis, realizing the self-supply of water for the hydrogen production process. A comprehensive examination is performed via modelling the integrated system to assess the influences of mass flow rates and nanofluid parameters on system function. Results reveal that the system performance is more sensitive to the mass flow rate of nanofluid than that of coolant, and concentrated nanofluids can easily affect system performance by adjusting their depth. Furthermore, mass flow rates and nanofluid parameters are optimized using a genetic algorithm with multiple-objectives. It was determined that the direct contact membrane distillation (DCMD) unit is capable of producing sufficient water for the electrolysis process. The optimal system attains a hydrogen production rate of 1.95 × 10−5 kg/s, a specific thermal energy consumption of 310.18 kWh/m3, and a system efficiency of 22.39%. • A solar system for hydrogen production and seawater desalination is developed. • Self-supply of fresh water for solar hydrogen production is achieved in the system. • Parametric optimization is conducted by GA to utilize full spectrum solar energy. • Optimal system performance is gained by 10@10 nm nanofluid with f v = 2E-6 & S = 28 mm. • Optimal system gains efficiency of 22.39% alongside electrical efficiency ≥8%. [ABSTRACT FROM AUTHOR]

We present an analysis of high-resolution, near-infrared (NIR) spectra relative to the solar transit of Venus of 5–6 June 2012, as observed with the Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar Telescope in New Mexico. These observations offer the unique opportunity to probe the upper layers (above ∼84 km in altitude) of a thick, CO2-dominated atmosphere with the transmission spectroscopy technique—a proxy for future studies of highly-irradiated atmospheres of Earth-sized exoplanets. We were able to directly observe absorption lines from the two most abundant CO2 isotopologues, and from the main isotopologue of CO in the retrieved spectrum of Venus. Furthermore, we performed a cross-correlation analysis of the transmission spectrum using transmission templates generated with petitRADTRANS. With the cross-correlation technique, it was possible to confirm detections of both CO2 isotopologues and CO. Additionally, we retrieved a tentative cross-correlation signal for O3 on Venus. We demonstrate the feasibility of high-resolution, ground-based observations to study the chemical inventory of planetary atmospheres, employing techniques commonly used in exoplanet characterization. [ABSTRACT FROM AUTHOR]

The Ozone Mapping and Profiler Suites (OMPS) Nadir Mapper (NM) is a grating spectrometer within the OMPS nadir instruments onboard the SNPP, NOAA-20, and NOAA-21 satellites. It is designed to measure Earth radiance and solar irradiance spectra in wavelengths from 300 nm to 380 nm for operational retrievals of the nadir total column ozone. This study presents calibration and validation analysis results for the NOAA-21 OMPS NM SDR data to meet the JPSS scientific requirements. The NOAA-21 OMPS SDR calibration derives updates of several previous OMPS algorithms, including the dark current correction algorithm, one-time wavelength registration from ground to on-orbit, daily intra-orbit wavelength shift correction, and stray light correction. Additionally, this study derives an empirical scale factor to remove 2.2% of systematic biases in solar flux data, which were caused by pre-launch solar calibration errors of the OMPS nadir instruments. The validation of the NOAA-21 OMPS SDR data is conducted using various methods. For example, the 32-day average method and radiative transfer model are employed to estimate inter-sensor radiometric calibration differences from either the SNPP or NOAA-20 data. The quality of the NOAA-21 OMPS NM SDR data is largely consistent with that of the SNPP and NOAA-20 OMPS data, with differences generally within ±2%. This meets the scientific requirements, except for some deviations mainly in the dichroic range between 300 nm and 303 nm. The deep convective cloud target approach is used to monitor the stability of NOAA-21 OMPS reflectance above 330 nm, showing a variation of 0.5% over the observed period. Data from the NOAA-21 VIIRS M1 band are used to estimate OMPS NM data geolocation errors, revealing that along-track errors can reach up to 3 km, while cross-track errors are generally within ±1 km. [ABSTRACT FROM AUTHOR]

Triplet‐triplet annihilation upconversion (TTA‐UC) technology could convert low‐energy light into high‐energy light, and it is a very promising one of the upconversion technologies due to its non‐coherent excitation light, low required excitation optical power density and sensitizer/annihilator flexible adjustability. The application of TTA‐UC into photocatalysis could not only broaden the range of solar energy spectrum utilization, but also bring mild reaction conditions and higher product yields via avoiding the side reaction. However, the detailed catalytic mechanism of TTA‐UC is unclear. Therefore, in this review, we summarized and classified TTA‐UC photocatalytic chemical reactions in terms of mechanism. [ABSTRACT FROM AUTHOR]

We report on the spectral photoelectric yields of the surface materials of the lunar rover Rashid 1, built by the Mohammed Bin Rashid Space Centre in Dubai. The materials investigated are magnesium alloy, indium-tin-oxide, titanium, the commercial off-the-shelf solar panel cover-glass, and the graphite coatings on the Langmuir probes, namely Aerodag®G and Graphit 33. The yields of gold and silver plates were also measured for reference and calibration purposes. The photoelectric yield of some of these materials was measured in the past but only with photon energies up to 25 eV. The measurements were performed at the BABE facility (stemming from the BACH and BEAR synchrotron beamlines) within the framework of the European AHEAD2020 project operated by the Italian National Research Council CNR-IOM at the synchrotron light source Elettra, Italy. We scanned the 2.8–1240 eV energy region, covering most of the solar spectrum that can potentially lead to photoelectron emission on the Moon. The total electron emission rate per unit surface was estimated by combining the measured photoelectric yield curves with the solar spectral irradiance data from TIMED-SEE/SORCE experiments. The results of this study are needed as input in numerical simulations of the electron sheath forming around Rashid 1 or any similar lunar rover. Such numerical models help estimate the background signal for in-situ measurements of the density of the electron sheath forming above the Moon's surface. [ABSTRACT FROM AUTHOR]

Continuous observation of solar radio bursts (SRBs) throughout the year using the CALLISTO spectrometer generates a huge volume of spectral data. This study introduces a burst-classifier algorithm, which is an automated algorithm, to classify the SRB spectrum into three solar radio bursts, namely Type II (SRBT II), Type III (SRBT III) and Type IV (SRBT IV). The proposed algorithm was designed using four characteristic parameters derived from a collection of training dataset files. The characteristic parameters were derived from the intensity bursts observed on frequency channels and timesteps of the spectrum. This dataset consisted of 50 spectra of SRBT II and SRBT III, along with 40 spectra for SRBT IV, collected during the solar maximum of 2014 (Solar Cycle 24). After observations and analysis of the training dataset, each burst type was set up with a threshold. A training dataset of 80 data spectra from 2013 to 2016 was used to test the algorithm. Accuracy of the proposed algorithm was calculated using the percentage of true positives (TP) and false positives (FP). Findings demonstrate an accuracy of ∼74 % with 57 out of 80 spectra classified as TP and 23 spectra as FP. [ABSTRACT FROM AUTHOR]

In the period December 12, 2022, to February 28, 2023, we performed a series of UBVRI observations of 65 asteroids, including 50 primitive-type objects, which could be observed near perihelion at that time, and calculated their approximated reflectance spectra. The observations were aimed at searching for spectral signs of sublimation-driven dust activity in the asteroids and formation of a transient dust exosphere, which are caused by the presence of Н2О ice in their interior and the highest subsolar temperature. Based on the analysis of the accuracy and shape of approximated reflectance spectra of the primitive-type asteroids, a set of which was conventionally restricted by the geometric albedo value not exceeding 0.10, we found sublimation-driven dust activity in asteroids 164 Eva, 360 Carlova, and 750 Oskar by distinct short-term variations in the reflectance of these asteroids in the U band. During one of the nights, similar spectral changes and sublimation-driven dust activity related to them were detected in asteroid 629 Bernardina; the geometric albedo of this asteroid is somewhat higher (0.14 or 0.19), which may be indicative of a heterogeneous composition of its material and, apparently, a local outcropping of water ice on its surface. Moreover, in three asteroids of a high-temperature type, 757 Portlandia, 1121 Natascha, and 1687 Glarona, noticeable variations were detected in the entire spectral range; they may be connected with ejection of submicron dust particles from the surface by some other mechanisms. To substantiate and interpret the results of observations, we numerically modeled the reflectance spectra of conditional asteroids of taxonomic types C and S (with low- and high-temperature mineralogy, respectively), which are enveloped by an optically thin dust exosphere containing aggregate or homogeneous submicron particles of different composition. On the basis of this modeling, we introduce a quantitative criterion to identify a weak sublimation-driven dust activity in primitive-type asteroids in the visible range. [ABSTRACT FROM AUTHOR]

Solar‐driven water evaporation is an emerging technology in green technology of seawater desalination and sewage treatment. However, the quality of high cost, complex manufacturing, and a small amount of synthetic materials is the main obstacle to large‐scale applications. Biological carbon‐based materials have a large and efficient heat exchange area due to the naturally abundant pore structure, which plays an important role in regulating convection and radiant heat loss. However, single‐component carbon materials have limited photothermal conversion performance, which limits their large‐scale application. In this work, tobacco stem (TS) organisms loaded with Co/CoO nanoparticles are successfully prepared by one‐step pyrolysis. The synergistic effect of Co/CoO nanostructures and biocarbon materials enhances water evaporation performance, widening the absorption range of the material across the entire solar spectrum, and expanding the range of energy that can be converted into heat. Specifically, the water evaporation rate and photothermal conversion efficiency of TS ‐Co/CoO (0.20) reached 2.22 kg m−2 h−1 and 139.4%, respectively, and its evaporation rate is 1.7 times the direct carbonized tobacco and 4.35 times the pure water. This work provides a research idea for the multifunctional and effective utilization of waste biomass materials and the construction of bionic structure solar photothermal materials. [ABSTRACT FROM AUTHOR]

This study examined the effect of atmospheric, topographic, and Bidirectional Reflectance Distribution Function (BRDF) corrections of Sentinel-2 images implemented in Google Earth Engine (GEE) for use in land cover classification. The study was carried out in an area of complex orography in northern Spain and made use of the Spanish National Forest Inventory plots and other systematically located plots to cover non-forest classes. A total of 2991 photo-interpreted ground plots and 15 Sentinel-2 images, acquired in summer at a spatial resolution of 10–20 m per pixel, were used for this purpose. The overall goal was to determine the optimal level of image correction in GEE for subsequent use in time series analysis of images for accurate forest cover classification. Particular attention was given to the classification of cover by the major commercial forest species: Eucalyptus globulus, Eucalyptus nitens, Pinus pinaster, and Pinus radiata. The Second Simulation of the Satellite Signal in the Solar Spectrum (Py6S) algorithm, used for atmospheric correction, provided the best compromise between execution time and image size, in comparison with other algorithms such as Sentinel-2 Level 2A Processor (Sen2Cor) and Sensor Invariant Atmospheric Correction (SIAC). To correct the topographic effect, we tested the modified Sun-canopy-sensor topographic correction (SCS + C) algorithm with digital elevation models (DEMs) of three different spatial resolutions (90, 30, and 10 m per pixel). The combination of Py6S, the SCS + C algorithm and the high-spatial resolution DEM (10 m per pixel) yielded the greatest precision, which demonstrated the need to match the pixel size of the image and the spatial resolution of the DEM used for topographic correction. We used the Ross-Thick/Li-Sparse-Reciprocal BRDF to correct the variation in reflectivity captured by the sensor. The BRDF corrections did not significantly improve the accuracy of the land cover classification with the Sentinel-2 images acquired in summer; however, we retained this correction for subsequent time series analysis of the images, as we expected it to be of much greater importance in images with larger solar incidence angles. Our final proposed dataset, with image correction for atmospheric (Py6S), topographic (SCS + C), and BRDF (Ross-Thick/Li-Sparse-Reciprocal BRDF) effects and a DEM of spatial resolution 10 m per pixel, yielded better goodness-of-fit statistics than other datasets available in the GEE catalogue. The Sentinel-2 images currently available in GEE are therefore not the most accurate for constructing land cover classification maps in areas with complex orography, such as northern Spain. [ABSTRACT FROM AUTHOR]

We for the first time demonstrate ground-based remote sensing of Nitrous Oxide (N2O) over Hefei in eastern China from high resolution Fourier Transform Infra-Red (FTIR) solar spectra. We have retrieved Column-averaged Abundance of N2O (${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O ) from both Near-Infrared (NIR, 4000 to 11,000 cm−1) and Mid-Infrared (MIR, 2400 to 3200 cm−1) solar spectra and inspected their agreement. Generally, NIR and MIR measurements agree well with a correlation coefficient of 0.86 and an average difference of (1.33 ± 4.05) ppbv (NIR – MIR). By correcting the bias of the two datasets, we combine the NIR and MIR measurements to investigate seasonality and inter-annual trend of ${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O over Hefei. The observed monthly mean time series of ${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O minimize in June and maximize in September, with values of (316.55 ± 12.22) ppbv and (322.05 ± 12.93) ppbv, respectively. The ${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O time series from 2015 to 2020 showed an inter-annual trend of (0.53 ± 0.10) %/year over Hefei, China. We also compared the FTIR ${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O observations with GEOS-Chem model ${X_{{{\rm{N}}_2}{\rm{O}}}}$ X N 2 O simulations. They are in reasonable agreement with a correlation coefficient (R) of 0.71, but GEOS-Chem model underestimated the seasonality of the observations. This study can enhance current knowledge of ground-based high-resolution FTIR remote sensing of N2O in the atmosphere and contribute to generating a new reliable N2O dataset for climate change research. [ABSTRACT FROM AUTHOR]

HCFC‐22 is an ozone‐depleting substance with a greenhouse effect. The atmospheric mole fractions of HCFC‐22 have been increasing since the 1950s. Within the NDACC‐IRWG network, HCFC‐22 mol fractions can be retrieved from solar absorption spectra measured by ground‐based FTIR. However, only a few sites have provided HCFC‐22 data sets. Here, we demonstrate a harmonized FTIR HCFC‐22 retrieval strategy and generate a new global NDACC‐IRWG HCFC‐22 data set at 16 FTIR sites. The systematic and random uncertainties are 5.3%–8.7% and 3.2%–8.0%, respectively. A maximum HCFC‐22 column annual growth rate was observed in 2009 with a mean of 7.65 ± 1.39 ppt/year, and the HCFC‐22 annual growth rate decreased to 3.57 ± 1.39 ppt/year (2016–2020) and 2.15 ± 2.09 ppt/year (2021–2023). The annual growth rates derived from the FTIR measurements are compared to the ones derived from NOAA surface flask samplings and ACE‐FTS satellite measurements, and the three independent data sets show a good agreement. Plain Language Summary: Monitoring the atmospheric HCFC‐22 mol fraction and its long‐term trend is important to the stratospheric ozone layer and climate change. Ground‐based FTIR measurements within the NDACC‐IWRG community provide a powerful technique for observing atmospheric trace gases. However, due to different retrieval software and procedures among the sites, the record was too heterogeneous for monitoring the global evolution of HCFC‐22 over time. In this study, we propose a harmonized FTIR HCFC‐22 retrieval strategy and generate a global NDACC‐IRWG HCFC‐22 data set at 16 FTIR sites. The retrieval uncertainty of the FTIR HCFC‐22 is well presented and discussed. Based on the new FTIR HCFC‐22 measurements, the HCFC‐22 annual growth rates between 1990 and 2023 are evaluated. The results are compared with two independent data sets: NOAA flask samplings and ACE‐FTS satellite measurements. Good agreement among the three data sets is found, with a clear decrease in the growth rate of atmospheric HCFC‐22 in recent years. According to the latest Montreal Protocol, HCFC‐22 should be phased out within the next 5–6 years. The global FTIR observations will assure continuity into the next years and decades when HCFC‐22 mol fractions should start decreasing after the official phase‐out. Key Points: Implemented a harmonized NDACC‐IRWG FTIR HCFC‐22 retrieval strategy and provided a new global long‐term HCFC‐22 data setA decrease in the growth rate of the atmospheric HCFC‐22 column has been observed by FTIR measurements since 2009The FTIR, NOAA flask samplings, and ACE‐FTS satellite observations show a good agreement in the HCFC‐22 trend [ABSTRACT FROM AUTHOR]

Porous photonic structures have greatly advanced large‐scale radiative cooling application owing to its satisfying optical properties, easy‐designation, and low cost. However, current reported porous radiative cooling materials mainly focuses on uniform or random pore distribution structure, which failed to achieve precise spectrum control for sunlight and mid‐infrared light, thereby weakening the radiative cooling performance. Herein, gradient structural porous metamaterials (GSPMs) are proposed and successfully constructed for maximizing cooling effectiveness based on step‐by‐step freeze‐casting technology. The designed GSPMs with gradient micro‐nano porous structure can wide‐range scatter entire solar spectrum while possess gradual refractive index transition to increase air‐medium interface absorption at mid‐infrared regions. Notably, solar reflectivity and mid‐infrared emissivity of GSPMs reach 97.3% and 97.6%, achieving maxinum cooling temperature of 8.7 °C and net cooling power of 94.1 W m−2, presenting a higher cooling effect than random porous materials. Moreover, GSPMs enable achieve compatibility with color aesthetic and cooling superiorities due to selective spectra response behavior, as well as can be applied in building materials, realizing efficient energy saving and CO2 emission reduction. This work proposed gradient porous structure can achieve highly efficient daytime radiative cooling, offering new possibilities in the structure design of next‐generation porous radiative cooling materials. [ABSTRACT FROM AUTHOR]

Mimicking the characteristics and achieving specific functions of biological systems is stirring but challenging. Generally, pigments in the commercial coating can only achieve a similarity in chromaticity, while cannot obtain a similarity in the solar reflective spectrum whose difficulty resides in simulating spectral characteristics simultaneously. Unfortunately, traditional organic pigments show poor weather and heat resistance. Herein, with the little difference in the color difference (ΔEab*), the high spectral similarity, as well as adjustable green peak and similar red edge slope compared with the common plants (pagoda tree leaf, etc.) in 400–2500 nm, is also attained. It is achieved by the interlayer confined organic pigment in Mg/Al‐layered double hydroxide (Mg/Al‐LDH) layers. The corresponding biomimetic leaf displays high hyperspectral performance with a spectral angle cosine of 0.9922 and heat resistance at 120 °C. The longer weather resistance than that of mechanical mixing is also demonstrated. The intercalated chromophores of sodium copper chlorophyllin in the Mg/Al‐LDH and the interlayer confinement of Mg/Al‐LDH contribute to the excellent performance. This work provides a green pigment and a biomimetic leaf requiring the same chromaticity and spectrum as green plants, filling the long‐term use demand gap for heat and weather‐resistant biomimetic vegetation. [ABSTRACT FROM AUTHOR]

The generation of hydrogen fuel, and wastewater treatment according to solar-driven catalysis possesses considerable prospective for establishing a carbon-neutral and ecologically sound power infrastructure. Driven by this problem, we suggest in this study, adopting a simple impregnation method, a customized association of CoAl-LDH and graphitic carbon nitride (CN), a visible light active narrow and wide band gap semiconductors. Several characterization approaches were implemented to understand the CoAl-LDH@g-C 3 N 4 (CACN) composites' physiochemical and optical features. The CACN hetero structural forms exhibited significantly improved solar light-induced photocatalytic H 2 generation and dye pollutants decomposition in contrast with pristine materials. The most effective catalyst 5 wt% CoAl-LDH@g-C 3 N 4 (5-CACN) generated the highest hydrogen (∼430.7 μmolg−1h−1), which is 11.9-fold H 2 production efficiency compared with CN and depicted significant Brilliant black dye removal efficacy via photocatalytic degradation (up to ∼79%). This was primarily ascribed to the development of the Type-II CACN heterojunctions, which promoted the separation of charges and expanded the abundance of surface-active sites while absorbing the visible spectrum of solar light. To examine the photocatalytic proficiency for H 2 production and dye pollutant removal over CoAl-LDH@g-C 3 N 4 heterojunction nanocomposites synthesized via a facile impregnation approach and plausible schematic photocatalytic mechanism for H 2 production and Brilliant black dye pollutant removal under visible photons illumination. [Display omitted] • A facile single-step hydrothermal method was employed to synthesize the CoAl-LDH nanotextures. • Type-II heterojunction CoAl-LDH@g-C 3 N 4 composites were prepared via a simple impregnation approach. • Type-II heterojunction CoAl-LDH@g-C 3 N 4 composites display an enhanced H 2 production during sunlight illumination. • Type-II heterojunction CoAl-LDH@g-C 3 N 4 depicts a significantly superior photocatalytic degradation of Brilliant Black dye in a water sample. • Plausible mechanism of Type-II heterojunction CoAl-LDH@g-C 3 N 4 for H 2 production and photocatalytic degradation of Brilliant Black dye. [ABSTRACT FROM AUTHOR]

In this study, we present optical and numerical analysis methods to enhance the absorbed power of metallic nanoantenna arrays on a glass substrate under solar irradiance. A comprehensive exploration of various materials (Au, Pt, core-shell Ag-Pt, and Al-Al 2 O 3 ), morphologies (rectangular prism, cylindrical, triangular prism, and hexagram prism with the same volume of metal), and arrangements (periodic, disorder, and amorphous) was conducted to optimize absorbed power and heat production for maximizing the photothermal effect. In periodic arrangements, the absorbed power increased 1.5 to 3 times (minimum to maximum) by optimizing the period across different nanoantenna configurations. Morphologies characterized by sharp angles (triangular, hexagram) exhibited 1.3 to 1.7 times higher absorbed power. Despite Pt's shorter absorption decay length, it demonstrated broader absorption across the solar spectrum, resulting in 1.15 to 1.3 times more absorbed power than Au. Incorporating an Ag core with a Pt shell enhanced the absorbed power by 1.2 to 1.35 times compared to Au. The hexagram Ag-Pt nanoantenna displayed the highest absorbed power in periodic and disordered arrangements, while the triangular Pt excelled in amorphous configurations. The triangular Al-Al 2 O 3 nanoantenna exhibited 1.14 times higher absorbed power compared to the rectangular Au, presenting a cost-effective manufacturing option. The behavior of plasmon fields and destructive interference was investigated for the nanoantenna array. Three absorption regions were observed: near-distance with minimum absorption due to plasma turbulence, middle-distance (resonance period) with maximum absorption due to plasmon fields enhanced each other, and far-distance with constant absorption due to interference happening between the nanoantenna and incident light without other effects. [ABSTRACT FROM AUTHOR]

The Rank-Ordered Multifractal Analysis (ROMA) is a tool designed to characterize scale (in)variance and multifractality based on rank ordering the fluctuations in "groups" characterized by the same mono-fractal behavior (Hurst exponent). A range-limited structure-function analysis provides the mono-fractal index for each rank-ordered range of fluctuations. We discuss here two examples of multi-scale solar wind turbulence and complexity where ROMA is applied on the following: (a) data collected by Ulysses spacecraft in the fast solar wind, outside the ecliptic, between 25 and 31 January 2007, at roughly 2.5 Astronomical Units (AU) from the Sun, in the Southern heliosphere, at latitudes between −76.5 and −77.3 degrees, and (b) slow solar wind data collected in the ecliptic plane by Venus Express spacecraft, at 0.72 AU, on 28 January 2007. The ROMA spectrum of fast solar wind derived from ULYSSES data shows a scale-dependent structure of fluctuations: (1) at the smallest/kinetic range of scales (800 to 3200 km), persistent fluctuations are dominant, and (2) at the inertial range of scales (104 to 2 × 105 km), anti-persistent fluctuations are dominant, but less clearly developed and possibly indicative for the development of instabilities with cross-over behavior. The ROMA spectrum of the slow solar wind derived from Venus Express data, suggests a different structure of turbulence: (1) fully developed multifractal turbulence across scales between 5 × 104 and 4 × 105 km, with the Hurst index changing from anti-persistent to persistent values for the larger amplitude magnetic fluctuations; (2) at the smallest scales (400 to 6400 km), fluctuations are mainly anti-persistent, and the ROMA spectrum indicates a tendency towards mono-fractal behavior. [ABSTRACT FROM AUTHOR]

The anomalous cosmic rays have been studied for about fifty years. Through theoretical and numerical models, we can learn how and where they are originating. When Voyager 1 and 2 spacecraft observed the solar wind termination shock, the main efforts were focused on try to explain the source spectrum and the acceleration mechanism. Nevertheless, there is another feature of the spectrum that need a better understanding, and it is related with the peak intensity in the energy spectrum, that occurred at different energies in consecutive solar minima. Qualitatively, it can be explained in terms of drifts and its relation with the acceleration process. In the past some works have been partially successful to explain the observations. In this paper we do another effort to explain the shift in the peak intensity of anomalous cosmic ray energy spectrum. We use a numerical model which includes diffusive shock acceleration, and the effects of the heliosheath. The present work analyzes the role played by different factors in the energy shift of the peak intensity between two successive minima, in particular the location of the region of observations with respect to the shock, the heliospheric distance, the effects of turbulence on the reduction of weak scattering drifts, as well as a possible latitudinal dependence in the ion injection on the shock. [ABSTRACT FROM AUTHOR]

The study examined the photo-stability of the thermal control coating (TCC), a class of "Optical Solar Reflectors", used in spacecrafts. This TCC is achieved by applying a layer of dielectric ceramic paste (DCP) onto the substrate using a printer (PCB printing). The DCP was prepared from filler (ground Al 2 O 3 ceramic) and solvent with thickener (terpineol with ethylcellulose). The coating obtained by high-temperature firing (T = 850 оC, 2 h) has high reflectivity in the solar range of the spectrum (0.2–2.5 μm) with the solar absorptance (α s) of DCP equal to 0.143. It has high adhesion and photo-stability that exceeds photo-stability parameters of ZnO, TiO 2 , BaSO 4 , and CaSiO 3 pigments. The developed coating can be recommended not only as a TCC for spacecrafts, but also as a protective or dielectric layer in manufacturing of printed circuit boards in various fields of technology, where increased resistance to solar radiation or its ultraviolet region is required. [ABSTRACT FROM AUTHOR]

Featured Application: This work has the potential to have a great impact on wastewater treatment plants. The currently adopted methods for the degradation of emerging water micropollutants, such as Diclofenac, are not efficient enough, leading to only 20–40% degradation. Our photocatalyst is a cheap and sustainable tool that allows for up to 90% degradation over 120 min, even when just using visible light sources, meaning it is superior to the dangerous UV-driven photolysis typically observed for this class of compounds. Dangerous emerging water micropollutants like Diclofenac are harming ecosystems all over the planet, and immediate action is needed. The large bandgap photocatalysts conventionally used to degrade them need to be more efficient. Cu2ZnSnS4, a well-known light absorber in photovoltaics with a bandgap of 1.5 eV, can efficiently harvest an abundant portion of the solar spectrum. However, its photocatalytic activity has so far only been reported in relation to the degradation of organic dyes, and it is usually used as a benchmark to assess the activity of a photocatalyst without testing its actual potential on a hazardous water micropollutant conventionally encountered in primary and secondary waters. Here, we report the promising photocatalytic activity of Cu2ZnSnS4 nanoparticles in the degradation of Diclofenac, chosen as a benchmark for dangerous emerging water micropollutants. [ABSTRACT FROM AUTHOR]

The X‐Ray Sensor (XRS) has been making full‐disk observations of the solar soft X‐ray irradiance onboard National Oceanic and Atmospheric Administration's (NOAA) Geostationary Operational Environmental Satellites since 1975. Critical information about solar activity for space weather operations is provided by XRS measurements, such as the classification of solar flare magnitude based on X‐ray irradiance level. The GOES‐R series of XRS sensors, with the first in the series launched in November 2016, has a completely different instrument design compared to its predecessors, GOES‐1 through GOES‐15. To provide continuity, the two GOES‐R XRS spectral bands remain unchanged providing the solar X‐ray irradiance in the 0.05–0.4 nm and 0.1–0.8 nm bands. The changes for the GOES‐R XRS instrument included using Si photodiodes instead of ionization cells to improve performance, using multiple channels per X‐ray band to allow for a wider dynamic range, and providing accurate radiometric calibrations using the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility in Gaithersburg, Maryland. In addition to the standard XRS data product of solar irradiances in the two X‐ray bands, a new real‐time flare location data product is also available from the GOES‐R XRS instruments because two channels are quadrant photodiodes for position detection. The design and pre‐flight calibration results for this next‐generation XRS instrument are presented here in this XRS Paper‐1, and in‐flight solar X‐ray measurements from GOES‐16, GOES‐17, and GOES‐18 are provided in the XRS Paper‐2. Key Points: New technology for the Geostationary Operational Environmental Satellites (GOES) X‐Ray Sensor (XRS) is now continuing the five‐decade record of solar X‐ray flare monitoringNOAA measurement requirements for XRS led to a new design of the XRS with four photometers to measure the two standard X‐ray bandsThis new XRS instrument has improved pre‐flight calibrations and a new capability to provide real‐time the location of flares on the Sun [ABSTRACT FROM AUTHOR]

Integrating hierarchical plasmonic cavities into photocatalysis offers a promising avenue for expanding the light utilization range to cover the entire solar spectrum. However, fabricating these nanostructures with seamless size transitions for a wide plasmon resonant range remains technically challenging, requiring precise nanofabrication control and often relying on expensive and laborious techniques like e-beam lithography and reactive ion etching. Herein, a one-step forming strategy was explored to fabricate simple yet hierarchical plasmonic cavities featuring the surface nanodome array-integrated plasmonic Fabry–Pérot cavity through a facile large-area nanoimprinting method. This design leverages a uniform feature size and periodic arrangement to broaden the light utilization range of TiO2 across the entire solar spectrum (200–2500 nm). It consists of an upper nanodome array cavity with vertically continuous graded sizes for broadband absorption (200–1500 nm), coupled with a bottom plate cavity that enlarges the overall cavity size to extend the range to 2500 nm. Remarkably, simply adjusting the thickness of the plate cavity can tune the resonant position, eliminating the need for expensive mold modifications. When combined with TiO2, this hierarchical plasmonic cavity significantly enhances the photocatalytic hydrogen evolution rate to 36.3 µmol/h, achieving a remarkable 9.8-fold increase compared to pure TiO2 under full-spectrum illumination. This approach offers a convenient and inexpensive alternative to sophisticated nanofabrication techniques for large-area hierarchical plasmonic cavities with broadband plasmon resonance to enhance the photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

Solar heating of the upper ocean is a primary energy input to the ocean‐atmosphere system, and the vertical heating profile is modified by the concentration of phytoplankton in the water, with consequences for sea surface temperature and upper ocean dynamics. Despite the development of increasingly complex modeling approaches for radiative transfer in the atmosphere and upper ocean, the simple parameterizations of radiant heating used in most ocean models can be significantly improved in cases of near‐surface stratification. There remains a need for a parameterization that is accurate in the upper meters and contains an explicitly spectral dependence on the concentration of biogenic material, while maintaining the computational simplicity of the parameterizations currently in use. Here, we assemble observationally‐validated physical modeling tools for the key controls on ocean radiant heating, and simplify them into a parameterization that fulfills this need. We then use observations from 64 spectroradiometer depth casts across 6 cruises in diverse water bodies, 13 surface hyperspectral radiometer deployments, and broadband albedo from 2 UAV flights to probe the accuracy and uncertainty associated with the new parameterization. A novel case study using the parameterization demonstrates the impact of chlorophyll concentration on the structure of diurnal warm layers. The parameterization presented in this work will allow for better modeling of global patterns of sea surface temperature, diurnal warming, and freshwater lenses, without a prohibitive increase in complexity. Plain Language Summary: Most of the sunlight that hits our planet is absorbed by the ocean as heat, and the vertical distribution of this heat influences the circulation patterns of the atmosphere and upper ocean. Phytoplankton in the ocean also absorb sunlight, preventing it from heating deeper water. It is important, therefore, for ocean models to have a realistic representation of the solar heating profile as a function of the phytoplankton concentration. However, current parameterizations of solar heating in ocean models do not work well at shallow depths. To remedy this, we use intuitive physical modeling tools to develop a new parameterization that balances simplicity and accuracy and can be applied across all types of ocean modeling. We compare our parameterization to several types of direct measurements to better understand its accuracy and limitations. Finally, we conclude with a case study demonstrating the value of the new parameterization in a novel application. Key Points: Using empirical physical modeling tools, we develop a bio‐physical radiant heating parameterization that remedies a gap in the literatureIn situ observations of the underwater and surface solar spectrum and the surface albedo are used to probe the parameterization's accuracyThe parameterization is applied in a first‐of‐its‐kind case study of the sensitivity of diurnal warm layers to chlorophyll concentration [ABSTRACT FROM AUTHOR]

The fundamental scientific and engineering knowledge concerning the solar power curve, which maps solar irradiance and other auxiliary meteorological variables to photovoltaic output power, has been gathered and put forward in the preceding tutorial review. Despite the many pages of that review, it was incomplete in the sense that it did not elaborate on the applications of this very important tool of solar energy meteorology. Indeed, solar power curves are ubiquitously needed in a broad spectrum of solar forecasting and solar resource assessment tasks. Hence, this tutorial review should continue from where it left off and present examples concerning the usage of solar power curves. In a nutshell, this tutorial review, together with the preceding one, should elucidate how surface shortwave radiation data, be they ground-based, satellite-retrieved, or model-output, are bridged to various power system operations via solar power curves. [ABSTRACT FROM AUTHOR]

[Display omitted] • (SnFe 2)O x photocatalysts with significant photothermal catalytic degradation capabilities for CTC·HCl. • Mid-gap levels from Fe2+ and Fe3+ ions via IVCT and d – d transitions. • The mid-gap levels lead to distinct photocurrent characteristics under different incident wavelengths. • Electrons activated by visible and near-infrared light undergo cascaded transitions with UV light assistance. We present a comprehensive photocurrent characterization to explore the near-infrared (NIR) response and photothermal effects induced by mid-gap levels in (SnFe 2)O x (SFO) nanoparticles. X -ray photoelectron spectroscopy and diffuse reflectance spectroscopy revealed multiple mid-gap levels due to multivalent Fe ions. The SFO photocatalyst displayed a noticeable temperature rise under NIR irradiation and a considerable photothermal effect across the full solar spectrum during the photocatalytic degradation of chlortetracycline hydrochloride (CTC·HCl). In photothermal catalysis, after 150 min, SFO was able to remove 88% of CTC·HCl (60 mg/L), outperforming photocatalysis (79%) and thermal catalysis (73%). Rapid and slow response processes were observed in the photocurrent characterization under light-emitting diodes of different wavelengths (365–1500 nm), which revealed a clear dependence on the incident wavelength. Furthermore, innovative photocurrent response tests using alternating ultraviolet (UV) and NIR irradiation revealed that, in the presence of mid-gap levels, UV-excited electrons can aid NIR-excited electrons in achieving cascaded electron transitions, enhancing the utilization of NIR-excited electrons. Our findings demonstrate that mid-gap levels effectively improve the utilization of low-energy photons and boost the photocatalytic process through photothermal effects and increased active charge carrier density. [ABSTRACT FROM AUTHOR]

• Recent researches on various types of photocatalysts and heterojunctions have been outlined. • Recent researches on wastewater treatment by photocatalysis have been summarized. • Investigated photocatalysts for air purification have been summarized. • The application of photocatalysis for conversion including CO 2 reduction and H 2 evolution have been summarized. In the quest for effective solutions to address Environ. Pollut. and meet the escalating energy demands, heterojunction photocatalysts have emerged as a captivating and versatile technology. These photocatalysts have garnered significant interest due to their wide-ranging applications, including wastewater treatment, air purification, CO 2 capture, and hydrogen generation via water splitting. This technique harnesses the power of semiconductors, which are activated under light illumination, providing the necessary energy for catalytic reactions. With visible light constituting a substantial portion (46%) of the solar spectrum, the development of visible-light-driven semiconductors has become imperative. Heterojunction photocatalysts offer a promising strategy to overcome the limitations associated with activating semiconductors under visible light. In this comprehensive review, we present the recent advancements in the field of photocatalytic degradation of contaminants across diverse media, as well as the remarkable progress made in renewable energy production. Moreover, we delve into the crucial role played by various operating parameters in influencing the photocatalytic performance of heterojunction systems. Finally, we address emerging challenges and propose novel perspectives to provide valuable insights for future advancements in this dynamic research domain. By unraveling the potential of heterojunction photocatalysts, this review contributes to the broader understanding of their applications and paves the way for exciting avenues of exploration and innovation. [Display omitted] [ABSTRACT FROM AUTHOR]

The practical application of solar energy harvesting urgently calls for the facile preparation of high‐performance ultrablack surfaces with broadband and omnidirectional light absorption performance; however, some roadblocks still need to meet these requirements simultaneously. Herein, cone‐array ultrablack (CAUB) surfaces are prepared by combining feasible template replication and blade coating techniques. The elaborate micro‐sized cone structure and high absorptive materials (polydimethylsiloxane@carbon black, PDMS@CB) offer the CAUB extremely high, broadband, and omnidirectional light absorption over the solar spectrum with an average absorbance of 99.35%. Under one sun irradiation, the CAUB can efficiently absorb solar energy, reaching a surface temperature as high as 75 °C. A solar‐thermal‐electric generator (STEG) made from the CAUB film demonstrates real‐time solar‐heat‐electric conversion, achieving a high output power density of 330 µW cm−2. The CAUB film possesses excellent water repellency, flexibility, chemical solvent resistance, and potential for large‐scale production, satisfying the application requirements of solar energy harvesting and utilization. [ABSTRACT FROM AUTHOR]

Utilization of the near‐infrared (NIR) light in the solar spectrum is critical for efficiency improvement of photocatalytic H2 evolution. However, common semiconductors have low response to the NIR light and narrow bandgap semiconductors have inappropriate redox potentials. Here, the study presents a new dual‐functional up‐conversion strategy in one sensitizer for promoting photocatalytic hydrogen production reactions by converting NIR light to visible light and high‐energy electrons simultaneously, via photon‐photon conversion and photo‐electronic process, respectively. Using WO3:Yb,Er as the sensitizer and Zn0.5Cd0.5S as the hydrogen evolution reaction catalyst, a photocatalytic hydrogen release rate of 24.3 mmol g−1 h−1 under simulated solar‐light has been achieved without using any co‐catalyst. After loading Ni2P as a co‐catalyst, the photocatalytic hydrogen production performance can be further improved to 41.3 mmol g−1 h−1 at 10 °C and 93.3 mmol g−1 h−1 under non‐temperature‐controlled conditions, exceeding most photocatalysts. This work offers a new strategy to improve the NIR light utilization of the solar‐light for promoting photocatalytic hydrogen generation through synergistic photo‐optical, photo‐electronic, and photo‐thermal effects. [ABSTRACT FROM AUTHOR]

Effects of the extreme-ultraviolet (EUV) late phase of solar flares on the ionosphere were rarely studied. Here we simulated such effects on the ionospheric electron density using an ionosphere−thermosphere coupled model driven by the realistic solar spectrum observed during the X1.8 flare on 2012 October 23. Global total electron content (TEC) observations and simulations showed that the dayside ionospheric TEC during the EUV late phase increased more than that of the flare's main phase. We examined the performance of the model for flares with EUV late phase. The results showed that the F-region electron density enhancement and recovery did not vary in the same pace as the temporal variations of the EUV late phase, and the presence of the EUV late phase prolonged the recovery of electron density by ∼9 hr. We also found that the enhancement in electron density was mainly determined by the chemical production, while the recovery of electron density was primarily controlled by the electric field transport effects. This study enhanced understanding of the intricate physical and photochemical processes governing Earth's space environment and similar planetary systems during solar flare events with EUV late phase. [ABSTRACT FROM AUTHOR]

A technique for determining the tropospheric ozone (TO) content from the spectra of outgoing thermal infrared (IR) radiation based on the principal component method and neural network approach is proposed. To train the artificial neural networks, TO data calculated from ozone profiles of vertical ozone content derived from ozonesondes are used. The TCO is considered the ozone content in the atmospheric layers from the earth's surface to pressure levels of 400 and 300 hPa. The error of approximating TO values on training data is 2.7 and 3.6 DU for layers below 400 and 300 hPa, respectively. The methodology is validated on the basis of comparison with ground-based TO measurements at the NDACC international observing network of stations using solar infrared spectra. The mean standard deviations of the differences between the ground-based infrared measurements at 19 stations and the derived TO values from the IKFS-2 data were about 3 DU. The mean differences depend on the altitude and geographical location of the ground station, varying from +3 to –12 DU. The discrepancies between the ground-based measurements and satellite data correspond to the results of other authors obtained for the IASI satellite instrument, which is close in characteristics. The paper presents examples of the global distribution of mean monthly TO values for different seasons. [ABSTRACT FROM AUTHOR]

An experiment measuring the solar far-ultraviolet-ultraviolet (FUV-UV) irradiance with spectral resolution better than 0.1 nm in the wavelength range from 170 to 400 nm was carried out by the "HongHu-6" high-altitude balloon that flew to the bottom region of the near-space in September 2022. This experiment was based on the fact that solar FUV-UV penetrates through a complex cross-section window of the upper atmosphere, from outer to near space. The solar FUV-UV deposits energy in the upper atmosphere, which provides a key to answer scientific questions on the most important energy contributor to overall heating sources of the near space and how the near-space environment responds to solar activities. In the wavelength range between 150 and 210 nm, irradiance maps from active regions of the solar corona, the comparative small cross-section of molecular oxygen allows certain wavelengths of the band to arrive at altitudes between 20 and 30 km above the ground, indicating solar flares could directly impact the bottom region of the near space. Solar UV irradiance in the wavelength range 210 – 400 nm is absorbed by the upper atmosphere as a function of wavelength, and energy is deposited vertically in the lower regions of the near space. This experiment historically provides measurement data to fill a gap in the wavelength shorter than 280 nm in the lower regions of the near space. The solar FUV-UV spectrometer (SUVS) is a compact instrument based on improved Roland circle optics to adapt to the "HongHu-6" balloon payload platform. In this paper, we introduce the scientific goals of the solar FUV-UV spectrum measurement experiment, provide information on the SUVS instrument preflight calibration, and present the first results from the flight data. [ABSTRACT FROM AUTHOR]

The Hard X-ray Imager (HXI) aboard the Advanced Space-based Solar Observatory (ASO-S) is an instrument designed to observe hard X-ray (HXR) spectra and images of solar flares. Having 91 subcollimators to modulate incident X-rays, HXI can obtain 91 modulation data and 45 visibilities to reconstruct images with a spatial resolution as high as ∼ 3.1 arcsec. HXI was launched on 9 October 2022 and powered up on 17 October 2022. After the on-orbit testing phase lasting for three months, HXI was ready for regular observations on 18 January 2023. With fine-tuning of the detectors and electronics, we were able to expand the energy range from ∼ 30 – 200 keV to ∼ 10 keV – 300 keV, which significantly raised the scientific values of the data and the number of detected flare events. This paper presents the changes and improvements of HXI instrument since 2019, the important ground tests, on-orbit tests, and calibration works. We also present the light curves, spectra, and reconstructed images of one flare observed by HXI on 6 January 2023. [ABSTRACT FROM AUTHOR]

Under the dynamic influence of near-surface plasma, intricate dynamics of lunar dust have been observed during the Surveyors and Apollo missions in the form of Lunar horizontal glow. These dynamics are primarily driven by electrostatic forces generated by the continual bombardment of solar wind and highly energetic UV photons on the lunar surface and dust particles. This paper revisits the phenomenon of dust charging within the lunar photoelectron sheath and subsequent dynamics. The investigation has been carried out using a comprehensive model of the lunar photoelectron sheath characterized by observed solar spectra, latitude-dependent Fermionic photoelectrons, non-Maxwellian solar wind electrons, and cold ions. A test dust particle is introduced into the sheath, and equilibrium charge and static levitation conditions are derived. The result of dynamical evolution suggests the existence of a narrow parametric regime corresponding to the periodic hopping trajectory of the dust particle over the lunar surface. In other cases, the dust particles are found to re-impact the surface after a single ballistic hop. We further identify that the discrete charging of the dust could be crucial in determining the dust dynamics, particularly in the tenuous plasmas. The analysis of the discrete dust charging model reveals significant discrepancies with the continuous dust charging model and suggests a lower likelihood of static dust levitation in the lunar environment. The present study is important for unraveling the fundamental processes governing surface evolution on the Moon and other airless bodies throughout the Solar System. [ABSTRACT FROM AUTHOR]