Solid Absorbent Research Articles

A robust aerogel incorporated with phthalocyanine-based porous organic polymers for highly efficient gold extraction

The gold recovery from electronic waste liquid is of great significance to the recycling of precious metals and environmental restoration. Adsorption method is the preferred technique for gold recovery, but its expansion and application prospects were often limited by the workability and recyclability of common solid powder adsorbents. Herein, a solid absorbent powder (phthalocyanine-based POP, TD-POP) was integrated into chitosan/polyethyleneimine aerogel (TD-POP@CS/PEI-2) via a facile cross-linking and lyophilization strategy. As expected, TD-POP@CS/PEI-2 possessed outstanding mechanical toughness and stability, demonstrating efficient and specific adsorption for Au (III). The maximum adsorption capacity was 2169 mg g−1, higher than most of the absorbents. TD-POP@CS/PEI-2 aerogel also exhibited fast kinetics (recovery efficiency of 81.3 % within 3 h), good selectivity (recovery efficiency of 98.35 % at 10 times concentration of Al3+, Zn2+, Cu2+ Cd2+, Co2+, Ni2+, Mn2+, and Cr6+ than Au ions) and reusability (eight times). Multiple characterizations revealed the adsorption mechanism, which implied that the excellent adsorption properties of the aerogel were ascribed to the electrostatic attraction between cationic aerogel and AuCl4− anion, coordination interaction between nitrogen-containing active sites and Au (III), and reduction of Au (III) by TD-POP@CS/PEI-2 aerogel. This work provides a valuable and promising strategy to design scalable and sustainable adsorbents for capture precious metals, also promotes the development of integral adsorbent for environmental remediation.

Effect of coating temperature on the properties of CdS thin films coated by nebulizer spray pyrolysis method for photodetection applications

Nanostructured CdS-based photodetectors have been focused on recent years because of their high photosensitivity and quick response time. This work reports the photodetector characteristics of CdS thin films prepared using a nebulizer-assisted spray pyrolysis technique by varying substrate temperatures. The X-ray diffraction (XRD) pattern of CdS films exhibits hexagonal structure with orientation along the (002) plane and CdS films deposited at 450 °C exhibits a higher crystallite size of 53 nm. Morphological analysis shows that the small grains become large spherical flakes at higher substrate temperatures. The optical studies showed that around the visible region, the films exhibit solid optical absorbance, and when substrate temperatures rise to 450 °C, the energy bandgap value decreases to 2.29 eV. The photoluminescence (PL) spectra exhibit two emission peaks: a broad peak at 525 nm and a sharp dominant peak at 680 nm. The CdS thin film deposited at 450 °C produced the highest photoresponsivity (R) of 37.1 × 10-2 A/W, detectivity (D*) of 268 x108 Jones, external quantum efficiency (EQE) of 120 %, and response/recovery times of 0.92/0.28 s under 532 nm illumination. The study suggests that CdS thin films are suitable for visible photodetector applications due to their simple and cost-effective production process.

Effect of water on CO2 capture and phase change in non-aqueous 1,4-butanediamine/ethylene glycol biphasic absorbents: Role of hydrogen bond competition

Non-aqueous liquid–solid biphasic absorbents show significant potential for reducing energy consumption in CO2 capture. However, the high hygroscopic nature of amine compounds and the approximately 10 % to 20 % water vapor in natural gas plants’ flue gases challenge their efficiency and stability. This study investigated water’s effects on the CO2 absorption/desorption performance, phase-change behavior, and products of the non-aqueous absorbent 1,4-Butanediamine (BDA)/ethylene glycol (EG). Experimental results show that water significantly impacts absorption/desorption performance. The maximum CO2 loading and regeneration efficiency were 1.4199 mol·mol−1 and 89.85 %, respectively. Water leads to the gradual disappearance of phase changes, with solid-phase CO2 loading decreasing from 0.008 to 0.004 mol·g−1. Quantitative NMR demonstrates that carbamates and CO32-/HCO3- are the main CO2-related products in aqueous systems, with their relative proportions affected by water content. Quantum chemical calculations and molecular dynamics simulations reveal that water enhances absorption efficiency by participating in the catalytic environment and reaction process. Water-induced hydrogen bonding competition is the leading cause of weakened interactions between species. Specifically, H-bonds between carbamate/protonated amines were decreased by 23.94 %. The enhanced solvation effect reduces aggregation of the key products, contributing to the gradual disappearance of phase changes. This study provides insights into water’s effect on non-aqueous biphasic absorbents at the molecular level, offering a theoretical foundation for the development and optimization of absorbents suitable for use with steam-containing flue gases.

Numerical simulations of CO2 absorption by MgO-based sorbent in a gas–solid fluidized bed

Given that carbon dioxide (CO2) constitutes the predominant proportion of greenhouse gas emissions, its capture, utilization and storage have always been a subject of great concern. Gas-solid fluidized bed has become one of the commonly applied equipment for the removal of CO2 from flue gases owing to its advantages such as exceptional mixing effect and substantial interfacial area between the phases. However, there is a lack of attention to the mechanism of CO2 absorption by individually-tracked moving solid sorbents as well as their effects on the decarbonization performance in a gas–solid fluidized bed. In this study, CO2 removal model by solid particles based on MgO adsorbent was established with the implementation of the shrinking-core model and each particle was tracked individually. Results validated the accuracy of the absorption model and revealed that smaller sizes of the solid absorbent, lower inlet gas velocities and larger inlet CO2 mass fractions exhibit relatively high CO2 removal efficiency. In addition, the decarbonization performance of fluidized and packed beds was compared. The packed bed exhibits more uniform gas flow and higher CO2 removal efficiency, whereas the fluidized bed provides larger interphase contact area, which facilitates the heat transfer process. Through the analysis of a series of parameters, the results provide recommendations for improving the CO2 removal efficiency and help to explore the optimal protocol for the design of bed reactors for CO2 removal.

Multifunctional ytterbium oxide buffer for perovskite solar cells.

Perovskite solar cells (PSCs) comprise a solid perovskite absorber sandwiched between several layers of different charge-selective materials, ensuring unidirectional current flow and high voltage output of the devices1,2. A 'buffer material' between the electron-selective layer and the metal electrode in p-type/intrinsic/n-type (p-i-n) PSCs (also known as inverted PSCs) enables electrons to flow from the electron-selective layer to the electrode3-5. Furthermore, it acts as a barrier inhibiting the inter-diffusion of harmful species into or degradation products out of the perovskite absorber6-8. Thus far, evaporable organic molecules9,10 and atomic-layer-deposited metal oxides11,12 have been successful, but each has specific imperfections. Here we report a chemically stable and multifunctional buffer material, ytterbium oxide (YbOx), for p-i-n PSCs by scalable thermal evaporation deposition. We used this YbOx buffer in the p-i-n PSCs with a narrow-bandgap perovskite absorber, yielding a certified power conversion efficiency of more than 25%. We also demonstrate the broad applicability of YbOx in enabling highly efficient PSCs from various types of perovskite absorber layer, delivering state-of-the-art efficiencies of 20.1% for the wide-bandgap perovskite absorber and 22.1% for the mid-bandgap perovskite absorber, respectively. Moreover, when subjected to ISOS-L-3 accelerated ageing, encapsulated devices with YbOx exhibit markedly enhanced device stability.

Bimetallic solid solution MAX phase Ti2NbAlC2 as saturable absorber for passively Q-switched Er3+-doped fiber laser

In this paper, we demonstrated a stable Q-switched fiber laser operation with a central wavelength of 1531.43 nm using a bimetallic solid solution MAX phase Ti2NbAlC2 saturable absorber. The minimum pulse duration of 3.67 μs and the maximum repetition rate of 32.56 kHz were acquired at the pump power of 300 mW. Furthermore, the Q-switched pulse has a maximum output power of 1.08 mW and a maximum pulse energy of 33.14 nJ. Our results indicate that the Ti2NbAlC2 is a promising saturable absorber material. The bimetallic solid solution MAX phase materials may be developed as novel nonlinear photonic devices with outstanding performance.

Direct capture and separation of CO2 from air

Direct air capture (DAC) has attracted increasing interest and investment over the past few years. There are a fast-growing number of companies that entered the field and demonstrated DAC carbon removal setups and potential. However, current DAC methods are still based on solid absorbents or alkali solutions approaches which have low capture efficiency and low energy efficiency. This highlight proposed a promising CO2 capture technology, an electric energy driven closed-loop system for the direct removal of CO2 from ambient air which are based on two individual technologies: Polyam-N-Cu hybrid system promoted CO2 capture with ocean as anthropogenic CO2 sink and a chloride-mediated electrochemical pH swing system to remove CO2 from oceanwater.

Performance Optimization of Auxetic Structures on Energy Absorption of Cylindrical Sandwich Using Taguchi and ANOVA Methods

High engineering requirements of shock absorbers have increased interest in auxetic materials, which have higher specific energy absorption performance compared to conventional solid absorbers. Last decade, many optimization studies were conducted to improve the energy absorption performance of auxetic tubular structures. Most studies focused on adding inner and outer shells to thin-walled auxetic tubular absorbers with different types of lattice structures to enhance energy absorption of the cylindrical sandwiches. There are limited studies on thicker-walled auxetic tubes and their related shell thicknesses to optimize performance. In this study, the thickness of the thicker-walled auxetic core thickness (1.2 mm, 1.6 mm, 2 mm), shell thickness (16 mm, 20 mm, 24 mm), and auxetic lattice structure (Re-Entrant Circular, SiliComb, and ArrowHead) were optimized to improve the specific energy absorption of cylindrical sandwiches. The Taguchi method was used to determine the optimum parameters for cylindrical sandwiches. In addition, the effect ratio of the parameters on the specific energy absorption was investigated using the ANOVA method. The energy absorption properties of the cylindrical sandwiches were determined using the drop-weight test. The highest specific energy absorption was obtained using a shell thickness of 1.2 mm and a core thickness of 16 mm using an SiliComb lattice. It was determined that the lattice geometry was the most effective parameter on the specific energy absorption of cylindrical sandwiches, with an effect rate of 61.62%.

Imaging Solvent‐Triggered Gaseous Iodine Uptake on Single Covalent Organic Frameworks

AbstractCovalent organic frameworks (COFs) are promising solid absorbents for the treatment of gaseous iodine. However, extensive efforts are still focused on empirical optimizations of specific binding sites and pore structures in COFs, and the chemical control of gaseous iodine uptake on COFs remains challenging. In this study, the chemically triggered sorption properties of COF‐300 for I2 vapors at the single‐particle level with the dark‐field microscope (DFM) are explored. The present operando single‐particle DFM imaging method enables the direct visualization of an adsorption activity transformation from inactive COF‐300 to active solvated COF‐300 toward gaseous I2 vapors. Exploiting the useful reaction information from time‐lapsed DFM images, the tunable adsorption performance of solvated COF‐300 is quantitatively compared by various solvents. The results illustrate that the isopropanol (IPA)‐solvated COF‐300 achieves the optimum adsorption capacity for I2 among the absorbents. The reaction mechanism is elucidated to be the channel size enlargement and modification of internal surface chemistry in the IPA‐solvated COF‐300, producing a stable I2/IPA‐solvated COF‐300 complex after the sorption reaction. The present chemical control of the sorption behavior of COF‐300 revealed by DFM opens up a new fundamental paradigm for rationally developing high‐performance COF‐based absorbents for removing I2 vapors.

Directly irradiated liquid metal film in an ultra-high temperature solar cavity receiver. Part 1: Concepts and a quasi-steady-state analysis

Solar thermal energy has the theoretical potential to deliver heat at ultra-high temperatures (>1300 K), which can enable integration with state-of-the-art thermal energy storage systems and unlock new applications, including advanced power cycles and thermal processes. Liquid metals are prospective heat transfer fluids for such systems, given their favourable thermo-physical properties, while their aggressive corrosiveness is shown to be mitigated using compatible refractory containment materials. The conventional approach of collecting concentrated solar energy typically involves intermediate solid absorbers, in form of tubes or porous structures, which are prone to thermomechanical and chemical failure under high solar radiation. This paper investigates the use of directly irradiated liquid metal (tin) film, operating between 800 and 1673 K, in two possible cavity configurations: A ‘reflective cavity’ and an ‘absorptive cavity’. The former employs cavity walls as internal reflectors to entrap radiation by secondary reflections until directly absorbed by the liquid metal. In the latter, the directly irradiated film is used to moderate the initial shot of concentrated solar radiation before diffusively reflecting them to the absorptive cavity walls, which perform as a radiative heat exchanger used to preheat the liquid metal. The concept performance is evaluated using an approximate quasi-steady-state energy model of the receiver. The reflective cavity performance is found strongly dependent on the optical properties of its internal surfaces, which resulted in poor efficiencies (<40 %) without special treatments. The absorptive cavity demonstrated higher efficiencies (>70 %) with greater insensitivity to the optical properties, hence, promoting its consideration in future developments of this concept.

An efficient approach for the treatment of radioactive waste perfluoropolyether lubricants via a synergistic effect of thermal catalysis and immobilization

Perfluoropolyether (PFPE) lubricants are a kind of high-molecular polymer with many excellent properties. However, the use of PFPEs in the nuclear industry can lead to partial decomposition and carrying radionuclides, resulting in a large amount of radioactive waste PFPE lubricants annually. Moreover, radioactive waste PFPE lubricants are difficult to be effectively treated due to their high stability, the risk of possible leakage of radionuclides, and hypertoxic fluorine-containing by-products. In this study, without any precedent, a strategy of MnO2-catalyzed decomposition and Na2CO3-immobilized conversion was proposed for PFPE lubricant decomposition and fluorine immobilization simultaneously based on the Lewis acid-base and oxygen vacancies concept. A high fluorine conversion efficiency of 95.4% was achieved. Meanwhile, the mechanism of decomposition suggested that MnO2 mainly provided Lewis acid sites and attacked the (basic) fluorine or oxygen atoms in PFPE molecules. The decomposition of PFPE chains was proceed down and volatile fluorine-containing gas was released by partial electron transfer, intramolecular disproportionation reaction, and unzipping fashion. Subsequently, gas by-products could be further oxidized and then immobilized into fluoride salts by carbonate solid absorbents. Overall, this study provides a simple, safe, and potentially practical strategy for the harmless conversion of refractory fluorinated organic wastes, especially perfluoropolymers.

Effects of Xanthene Fluorophore on Light Physical Properties and their Dyeing Performance on Modacrylic Fabrics.

We designed the new xanthene dyes by introducing the donor and acceptor group of electrons in the 5' position of the carboxyphenyl ring. These synthesized dye molecules were identified using spectroscopy. And the photophysical studies, such as solvent optimization, were further explored before and after photodegradation of all synthesized dye compounds in both states (solution and solid). The resulting dyed modacrylic fabrics and measured their K/S values, reflectance (%), solid UV absorbance, and photoluminescence. All compounds are plotted on a chromaticity map in the pink region. During photodegradation, the stability of the molecule depends on the effect of the functional groups (donor to acceptor). In this case, ln[C/C0] (%) became the decreasing sequence from an electron donor to acceptor, as the electrons followed from the donation function group to the carboxylic function group. Therefore, the electron-accepting group dyes decompose rapidly during ultraviolet radiation.

DEPENDENCE OF OPTICAL PROPERTIES OF TWO-LAYERED METAL-DIELECTRIC SPHERICAL NANOPARTICLES ON TEMPERATURE

The dependences of the efficiency factors of radiation absorption by spherical hybrid nanoparticles of the core-shell system, respectively, with gold-quartz and quartz-gold materials with core radii r0 = 40, 50, 60, 70 nm and shell thicknesses Δr1 = 10, 20, 30 nm in the wavelength range of 300–3000 nm at temperatures of particles and surrounding quartz T = 300, 1173 K are theoretically calculated and studied. Essential change of radiation absorption by a nanoparticle is established with an increase of temperatures of nanoparticles and environment. The change of optical properties of nanoparticles significantly influences the efficiency of energy absorption of solar or optical radiation by nanoparticles, heating temperature of nanoparticles and environment and further thermal processes. The results are interesting for purposes of creation of high-temperature solid nanostructured absorbers of solar radiation containing absorbing radiation of a nanoparticle and also for creation of new materials for high-temperature nanophotonics.

Strong Resonant Light Absorption Band on Sub-Oxidized Metal Titanium Nanostructures

Nanopatterned or roughed metallic structures have received considerable attention due to the effective light absorption capability via optical effects of light confinement or photonic excitation of surface plasmon polaritons.1, 2, 3, 4, 5 However, individual metallic structures have limited light capture. To augment the solar light utilization, coupling of different absorption modes was developed within three-dimensional architectures.6, 7 Among these, the absorbers using dielectric-nanostructures interactions showed effective light harvesting, which exhibited enhanced photocatalysis and water splitting activities. Here, we present a solid visible light absorber made of proper sub-oxidation of metal Ti through a facial approach.First, surface nanostructures were prepared using a chemical etching process on cleaned metal Ti foils. Then, a thermal sub-oxidation was employed to diffuse oxygen into the sub-surface region of the metal Ti, forming titanium-oxides nanocomposites. The titanium-oxides are composed of titanium suboxides on the sub-surface of metal Ti nanostructures. The surface sharpness of nanostructures was checked by atomic force microscopy (AFM) and scanning electron microscopy (SEM) (Figure 1), showing favorable surface nanostructures. The nanostructures of quasi-prisms with sharp nano-curvatures allow light concentration in a more vigorous intensity. The affluent sharp edges of nanostructures could behave as “hot spots”. In Figure 2, the UV-vis absorption spectra of the as-prepared specimen disclose a strong resonant light absorption in the visible region with an almost four times enhancement. The resonant absorption band position and intensity are adjustable by controlling thermal diffusion parameters and surface structures.Our observation is quite distinctive from the absorption spectra of single phases, anatase or rutile phase TiO2, and the cases of mixed-phase TiO2-x nanoparticles. To our best knowledge, this is the first demonstration of uniquely strong resonant visible absorption band by sub-oxidized metal Ti nanostructures. The absorber is of particular interest in a wide range of extensive photo-responsive applications, such as optoelectronic devices, photovoltaics, and photocatalysis. The approach represents a new pathway to enable photonic absorption within nanostructures, not only for metal Ti but also for other related metallic structures. Acknowledgments: The authors acknowledge the research grants from EEA (European Economic Area)-Norway-Romania project# GRAFTID, RO-NO-2019-0616, EEA-Poland-NOR/POLNORCCS/PhotoRed/0007/2019-00, and the Research Council of Norway projects #314012 and #245963/F50.References Montoya JH, Seitz LC, Chakthranont P, Vojvodic A, Jaramillo TF, Norskov JK. Materials for solar fuels and chemicals. Nat Mater 16, 70-81 (2016).Chen X, Liu L, Huang F. Black titanium dioxide (TiO2) nanomaterials. Chem Soc Rev 44, 1861-1885 (2015).Robatjazi H, Zhao H, Swearer DF, Hogan NJ, Zhou L, Alabastri A, McClain MJ, Nordlander P, Halas NJ. Plasmon-induced selective carbon dioxide conversion on earth-abundant aluminum-cuprous oxide antenna-reactor nanoparticles. Nat Commun 8, 27 (2017).Atwater HA, Polman A. Plasmonics for improved photovoltaic devices. Nat Mater 9, 205-213 (2010).Maier SA, Brongersma ML, Kik PG, Meltzer S, Requicha AAG, Atwater HA. Plasmonics-a route to nanoscale optical devices. Adv Mater 13, 1501-1505 (2001).Shi X, Ueno K, Oshikiri T, Sun Q, Sasaki K, Misawa H. Enhanced water splitting under modal strong coupling conditions. Nat Nanotechnol 13, 953-958 (2018).Choi D, Shin CK, Yoon D, Chung DS, Jin YW, Lee LP. Plasmonic optical interference. Nano Lett 14, 3374-3381 (2014). Figure 1

Deep eutectic solvents with multiple hydroxyl sites for efficient and reversible absorption of SF6

Finding the adsorbents to efficiently and reversibly capture SF6 has important research significance. Most of the currently reported solid absorbents used to capture SF6 can have disadvantages such as difficult recovery and easy deactivation. To address this critical challenge, we here report an effective strategy to capture sulfur hexafluoride (SF6) using the hydroxyl-rich deep eutectic solvents (DESs) for the first time. The physical properties of as-prepared seven hydroxyl-rich DESs are systematically investigated, and the effects of structure of DESs, absorption temperature, pressure, and water content on absorption performance of SF6 also are inspected, respectively. In particular, ChCl-Gly (1:2) not only exhibits highest absorption capacity of SF6 with up to 0.1738 g SF6/g DES at 293.2 K and 1.0 bar, but also can be reused without significant decline in absorption capacity of SF6. In addition, the absorption mechanism study of SF6 is conducted by FTIR, NMR and DFT chemical calculations. The results suggest that the high absorption capacity of SF6 originates from the intermolecular hydrogen bonding of SF6 molecules and hydroxyl protons in DESs.

A solid solution-based millimeter-wave absorber exhibiting highly efficient absorbing capability and ultrabroad bandwidth simultaneously via a multi-elemental co-doping strategy

A multi-elemental co-doped solid solution, i.e. BaZr0.2Ti0.2Ni0.2W0.2Fe11.2O19, was developed, featuring an optimal reflection loss of −61.8 dB and a −20 dB bandwidth of 9.15 GHz at a matching thickness of 0.97 mm in the frequency range of 18–40 GHz.

Synergy of developed micropores and electronic structure defects in carbon-doped boron nitride for CO2 capture

With the aim of relieving the serious environmental and climate issues arising from excessive emission of anthropogenic CO2, extensive solid absorbents have been developed for CO2 capture. Among them, porous boron nitride (BN) is considered an ideal candidate due to its high specific surface area, abundant structural defects, low density, and outstanding chemical inertness. Herein, BN absorbents were synthesized from pyrolysis of melamine-boric acid precursors, and the effect of pyrolysis temperature (900, 1000, 1050 and 1100 °C) on the properties and performances was investigated. Various characterizations were performed to evaluate the physicochemical properties and CO2 uptake capacities of BN absorbents. The result demonstrated that a carbon-doped BN structure was achieved instead of a pure BN material, and the carbonization degree was enhanced with the increase of pyrolysis temperatures. BN absorbent pyrolyzed at 1100 °C exhibited the highest CO2 adsorption capacity of 3.71 mmol/g (273 K). The reason should be that the doping of carbon in the framework of BN contributed to the formation of abundant micropores, which enhanced the physical adsorption by offering more adsorption sites. At the same time, more negative charges on BN were induced by structural defects, which favored the chemical adsorption of CO2 by invoking charge-induced chemisorption interaction. This study clarified the role of pore structure and electronic structure defects in CO2 adsorption capacity of carbon-doped BN, which would open up more spacious avenues for the development of promising BN-based absorbents, or even catalysts.

A Solvent-Polarity-Induced Interface Self-Assembly Strategy towards Mesoporous Triazine-Based Carbon Materials.

Triazine-based materials with porous structure have recently received numerous attentions as a fascinating new class because of their superior potential for various applications. However, it is still a formidable challenge to obtain triazine-based materials with precise adjustable meso-scaled pore sizes and controllable pore structures by reported synthesis approaches. Herein, we develop a solvent polarity induced interface self-assembly strategy to construct mesoporous triazine-based carbon materials. In this method, we employ a mixed solvent system within a suitable range of polarity (0.223≤Lippert-Mataga parameter (Δf) ≤0.295) to induce valid self-assembly of skeleton precursor and surfactant. The as-prepared mesoporous triazine-based carbon materials possess uniform tunable pore sizes (8.2-14.0 nm), high surface areas and ultrahigh nitrogen content (up to 18 %). Owing to these intriguing advantages, the fabricated mesoporous triazine-based carbon materials as functionalized porous solid absorbents exhibit predominant CO2 adsorption performance and exceptional selectivity for the capture of CO2 over N2 .

A Solvent‐Polarity‐Induced Interface Self‐Assembly Strategy towards Mesoporous Triazine‐Based Carbon Materials

AbstractTriazine‐based materials with porous structure have recently received numerous attentions as a fascinating new class because of their superior potential for various applications. However, it is still a formidable challenge to obtain triazine‐based materials with precise adjustable meso‐scaled pore sizes and controllable pore structures by reported synthesis approaches. Herein, we develop a solvent polarity induced interface self‐assembly strategy to construct mesoporous triazine‐based carbon materials. In this method, we employ a mixed solvent system within a suitable range of polarity (0.223≤Lippert–Mataga parameter (Δf) ≤0.295) to induce valid self‐assembly of skeleton precursor and surfactant. The as‐prepared mesoporous triazine‐based carbon materials possess uniform tunable pore sizes (8.2–14.0 nm), high surface areas and ultrahigh nitrogen content (up to 18 %). Owing to these intriguing advantages, the fabricated mesoporous triazine‐based carbon materials as functionalized porous solid absorbents exhibit predominant CO2 adsorption performance and exceptional selectivity for the capture of CO2 over N2.

Productivity enhancement of single-slope solar still with novel bottom finned absorber basin inserted in phase change material (PCM): techno-economic and enviro-economic analysis.

Solar still is one of the economic and eminent ways of desalinating the available sea/brackish water into potable water. However, the distillate output from the solar still is moderate and various researches are being conducted to improve the productivity of solar still. In this research, a novel bottom finned (solid and hollow) absorber basin is designed and developed to enhance the heat transfer between absorber and phase change material (PCM) which further improves the freshwater productivity from the solar still. The results of the investigation are compared with the conventional solar still. The three single-slope solar stills considered developed for evaluating the effect of modification on the freshwater productivity are (i) conventional solar still (CSS), (ii) solar still with hollow finned absorber inserted in energy storage (SSHFES), and (c) solar still with solid finned absorber inserted in energy storage (SSSFES). The investigation results reported that the SSHFES has greater productivity when compared with the SSSFES and CSS. The freshwater productivity from the SSHFES is 4085 mL/m2 day, whereas the freshwater productivity from SSSFES and CSS is 3485 mL/m2 day and 2885 mL/m2 day, respectively. The efficiency of SSHFES and SSSFES is increased by 41.67% and 20.81% relative to the CSS. It is observed from economic analysis that the cost per liter (CPL) freshwater produced by SSHFES, SSSFES and CSS is about ₹ 2.3 ($ 0.032), ₹ 2.5 ($ 0.034), and ₹2.6 ($ 0.036), respectively. The payback periods of SSHFES, SSSFES, and CSS is 6.3 months, 6.8 months, and 7.1 months, respectively. Also, the enviroeconomic analysis conferred that the carbon credit gained from the SSHFES is $189.28 whereas SSSFES and CSS gained only $158.2 and $132.02. Based on the current study, it is observed that the solar still with hollow finned absorber inserted in energy storage (SSHFES) is effective when compared to others and it is viable for potable water production at cheaper costs.