Effective Separation Research Articles

One-step simultaneous and efficient extraction of multiple active compounds from Lycium barbarum by aqueous three-phase system: Focusing on polysaccharides

In the past few years, the aqueous three-phase system (A3PS) has attracted a lot of attention due to its effectiveness in the efficient separation. Polysaccharides, carotenoids and polyphenols were separated simultaneously from Lycium barbarum by an aqueous three-phase system (A3PS) formed by acetonitrile/betaine/K2HPO4 as a novel extraction technique. The system is characterized by small amount of machine reagents, few consumables and simple extraction steps. The effects of acetonitrile, betaine and K2HPO4 concentrations on the extraction efficiency were investigated by Response Surface Methodology. The optimum composition of A3PS were 26.2 % (w/w) acetonitrile, 10.2 % (w/w) betaine and 27.6 % (w/w) K2HPO4. Under this condition, the extraction efficiencies of carotenoids, polyphenols, and Lycium barbarum polysaccharides (LBP) were 42.12±0.10 %, 88.61±0.95 % and 84.63±0.46 %, respectively. The obtained LBP was characterized by several technologies. The LBP was proved to consist of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose and fucose in a proportion of 4.14:0.80:4.00:4.43:22.20:39.9:12.44:3.22:8.46:0.41. The molecular weight of LBP was 12554 Da. In addition, LBP exhibited excellent antioxidant activity. In general, as a rapid developing method of extraction and separation, A3PS had potential application in the simultaneous separation of multiple substances.

Enrichment of lithium ions for battery application by electrolysis through a nanoporous membrane

In recent years, lithium (Li) has become a valuable commodity widely used in rechargeable batteries. The present study aims to extract battery-grade lithium-ion, as lithium hydroxide (LiOH), from lithium chloride (LiCl) solution by the membrane electrolysis process. Experiments are performed using a commercial cation exchange membrane and an indigenous High flux-Nanofiltration 300 alkali resistant (HF-NF 300 AR) nanoporous membrane. The dual-chamber electrolytic cell incorporates a selective membrane to separate the feed and concentrate chambers containing LiCl solution and deionized water. These two chambers are connected with titanium electrodes through the external circuit. The in-situ design of the compact two-chambered acrylic electrolytic cell helps to separate metal ions from ionizable salts of sodium, lithium, magnesium, potassium, etc. The experiment is conducted on a laboratory scale by varying the LiCl concentration at voltages of 24 V and 36 V. The feed and concentrate solutions are analyzed for pH, conductivity, and total dissolved solids. Inductively coupled plasma-optical emission spectrometry evaluates the presence of metal ions in the solution. The study shows effective metal ion recovery and separation to achieve battery-grade Li.

ASSESSMENT OF THE PROBABILITY OF OCCURRENCE OF EMERGENCY SITUATIONS DURING OPERATION OF THE PYROLYSIS PLANT

The article discusses the issues of reliability and safety of operation of a pyrolysis plant for the disposal of used tires, which, in the context of an increasing volume of waste and the need for their effective disposal, is an urgent topic. The problem statement is related to the identification of factors affecting the reliability of the installation and the development of methods to prevent emergencies.The purpose of the study is to analyz the reliability of the pyrolysis plant and develop recommendations for its improvement. To achieve this goal, the causes and probabilities of failures of system elements are investigated, an analysis using the failure tree method is carried out. This method made it possible to identify the weaknesses of the system and assess the probability of their failures, which is critical to prevent emergencies.An assessment of the reliability of the installation showed that the greatest contribution to the probability of accidents is made by a malfunction of the gas separation system. This element is the most vulnerable due to its complexity and importance in the pyrolysis process, as it is responsible for the safe and effective separation of pyrolysis products. Any malfunction of the gas separation system can lead to the accumulation of dangerous gases, increasing the risk of explosions and fires. The identified emergencies require special attention to the development of effective measures to minimize them.The article proposes methods to improve the reliability of the system, the main of which is the redundancy of the most vulnerable elements. This will significantly reduce the probability of failures and increase the overall reliability of the installation. In addition, it is recommended to carry out regular inspections and maintenance of all elements of the system. These measures will help to identify and eliminate potential malfunctions in a timely manner, which will significantly reduce the likelihood of failures that can lead to emergencies.Thus, ensuring the reliability and safety of a pyrolysis plant for the disposal of used tires requires an integrated approach. Enabling redundancy of vulnerable elements and regular maintenance will minimize the likelihood of failures that can lead to emergencies and guarantee stable and safe operation of the system. These measures will not only increase the efficiency of disposal, but also ensure reliable and long-term operation of the installation.This article focuses on the importance of identifying vulnerable elements of the system and conducting regular maintenance to improve the reliability and safety of operation of the pyrolysis plant.

The Throttle Effect in Metal-Organic Frameworks for Distinguishing Water Isotopes.

Metal-organic frameworks (MOFs) have been widely used for separation, but amplifying subtle differences between similar molecules to achieve effective separation remains a great challenge. In this study, we utilize the fluorescent molecule uranine (Ura) to modulate the pores of zeolitic-imidazolate framework 8 (ZIF8), creating an unusual throttle effect. By monitoring fluorescence intensity changes in Ura, the transport diffusion process could be quantified to reveal the diffusion constant of solvents. When we pushed the Ura occupancy to its limit (from 59% to 76% and 98%), the diffusion rate decreases by 2 orders of magnitude. Most importantly, there is a significant dissymmetry between the two-way exchange rates of solvents, and the rates of H2O and D2O became distinguishable. Such unusual throttle effects disappear at low Ura occupancy of 59% and 76%. We believe that the throttle effect with small-molecule loading could provide a universal design principle for MOF-based applications, especially for isotope separation.

Excellent Wavelength Selectivity of p-AlGaN/n-Ga2O3 Solar-Blind UVC PD.

Due to the advantages of ultrawide bandgap, chemical stability, self-powered, and low cost, gallium oxide (Ga2O3) based photodetectors (PDs) are considered as one of the most promising solar-blind ultraviolet PDs, having garnered significant attention in fields such as missile warning and flame arc detection. High selective ratios and excellent responsivity are important to reduce the false alarm rate in solar-blind detection. However, due to the lack of p-type Ga2O3, existing Ga2O3-based PN PDs utilized heterostructures with narrower bandgap p-type semiconductors (e.g., p-GaN, p-SiC, etc.), inducing poor selective ratios with visible light and ultraviolet-A/B (UVA/B). Therefore, a high Al content AlGaN was used in this study to form a p-AlGaN/n-Ga2O3 solar-blind ultraviolet-C (UVC) PD. Since the bandgap of p-AlGaN aligned with the UVC region, the device exhibited exceptionally high selective ratios with R247nm/R360nm = 3.71 × 105 and R247nm/R300nm = 1.47 × 105 at 0 V, which surpassed the reported Ga2O3-based PN PDs. The formation of the type-II heterojunction facilitated the effective separation and transport of photogenerated carriers, resulting in high responsivity (0.36 A/W) under zero bias. Overall, the high selective ratios and high responsivity of the p-AlGaN/n-Ga2O3 PD in this paper provided a reliable pathway for self-powered solar-blind PDs with a low false alarm rate.

Building Asymmetric Zn−N3 Bridge between 2D Photocatalyst and Co‐catalyst for Directed Charge Transfer toward Efficient H2O2 Synthesis

AbstractTwo‐dimensional (2D) polymeric semiconductors are a class of promising photocatalysts; however, it remains challenging to facilitate their interlayer charge transfer for suppressed in‐plane charge recombination and thus improved quantum efficiency. Although some strategies, such as π–π stacking and van der Waals interaction, have been developed so far, directed interlayer charge transfer still cannot be achieved. Herein, we report a strategy of forming asymmetric Zn−N3 units that can bridge nitrogen (N)‐doped carbon layers with polymeric carbon nitride nanosheets (C3N4−Zn−N(C)) to address this challenge. The symmetry‐breaking Zn−N3 moiety, which has an asymmetric local charge distribution, enables directed interfacial charge transfer between the C3N4 photocatalyst and the N‐doped carbon co‐catalyst. As evidenced by femtosecond transient absorption spectroscopy, charge separation can be significantly enhanced by the interfacial asymmetric Zn−N3 bonding bridges. As a result, the designed C3N4−Zn−N(C) catalyst exhibits dramatically enhanced H2O2 photosynthesis activity, outperforming most of the reported C3N4‐based catalysts. This work highlights the importance of tailoring interfacial chemical bonding channels in polymeric photocatalysts at the molecular level to achieve effective spatial charge separation.

Indium Oxide Layer Dual Functional Modified Bismuth Vanadate Photoanode Promotes Photoelectrochemical Oxidation of Water to Hydrogen Peroxide.

The photoelectrochemical (PEC) dual-electron pathway for water oxidation to produce hydrogen peroxide (H2O2) shows promising prospects. However, the dominance of the four-electron pathway leading to O2 evolution competes with this reaction, severely limiting the efficiency of H2O2 production. Here, we report a In2O3 passivator-coated BiVO4 (BVO) photoanode, which effectively enhances the selectivity and yield of H2O2 production via PEC water oxidation. Based on XPS spectra and DFT calculations, a heterojunction is formed between In2O3 and BVO, promoting the effective separation of interface and surface charges. More importantly, Mott-Schottky analysis and open-circuit potential measurements demonstrate that the In2O3 passivation layer on the BVO photoanode shifts the hole quasi-Fermi level towards the anodic direction, enhancing the oxidation level of holes. Additionally, the widening of the depletion layer and the flattening of the band bending on the In2O3-coated BVO photoanode favor the generation of H2O2 while suppressing the competitive O2 evolution reaction. In addition, the coating of In2O3 can also inhibit the decomposition of H2O2 and improve the stability of the photoanode. This work provides new perspectives on regulating PEC two/four-electron transfer for selective H2O2 production via water oxidation.

In situ isotropic 3D imaging of vasculature perfusion specimens using x-ray microscopic dual-energy CT.

Ex vivo x-ray angiography provides high-resolution, three-dimensional information on vascular phenotypes down to the level of capillaries. Sample preparation for ex vivo angiography starts with the removal of blood from the vascular system, followed by perfusion with an x-ray dense contrast agent mixed with a carrier such as gelatine or a polymer. Subsequently, the vascular micro-architecture of harvested organs is imaged in the intact fixed organ. In the present study, we present novel microscopic dual-energy CT (microDECT) imaging protocols that allow to visualise and analyse microvasculature in situ with reference to the morphology of hard and soft tissue. We show that the spectral contrast of µAngiofil and Micropaque barium sulphate in perfused specimens allows for the effective separation of vasculature from mineralised skeletal tissues. Furthermore, we demonstrate the counterstaining of perfused specimens using established x-ray dense contrast agents to depict blood vessels together with the morphology of soft tissue. Phosphotungstic acid (PTA) is used as a counterstain that shows excellent spectral contrast in both µAngiofil and Micropaque barium sulphate-perfused specimens. A novel Sorensen-buffered PTA protocol is introduced as a counterstain for µAngiofil specimens, as the polyurethane polymer is susceptible to artefacts when using conventional staining solutions. Finally, we demonstrate that counterstained samples can be automatically processed into three separate image channels (skeletal tissue, vasculature and stained soft tissue), which offers multiple new options for data analysis. The presented microDECT workflows are suited as tools to screen and quantify microvasculature and can be implemented in various correlative imaging pipelines to target regions of interest for downstream light microscopic investigation.

Synchronous photocatalytic benzimidazole formation and olefin reduction by magnetic separable visible-light-driven Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 Nanocomposite

A visible light-responsive magnetically separable photocatalyst Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is fabricated using vanillin as a natural junction under ultrasonic agitation. Structural, morphological, optical, thermal, and magnetic assessments of the as-prepared catalyst are carried out. The photocatalyst successfully drives the simultaneous benzimidazole formation, and olefin hydrogenation with high atom economy under blue LED light and mild conditions. The photocatalytic activity of Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is significantly affected by the γ-Fe2O3:TiO2 weight ratio. PL spectra revealed the effective separation of carriers in the fabricated catalyst promoting its photocatalytic activity. The action spectra using the apparent quantum efficiency (AQE) exhibited the maximum AQEs at 520 and 750 nm in which the highest performance for styrene hydrogenation is observed. The title magnetically separable heterogeneous photocatalyst provides high yields of products under perfectly safe visible light, produces low/zero waste, and avoids using an external high-pressure hydrogen gas source, harmful solvents, undesirable additives, and reducing agents rendering green conditions for chemical reactions.

Separation of Lung Cancer Cells From Mixed Cell Samples Using Aptamer-Modified Magnetic Beads and Permalloy Micromagnets.

This study involved the design and fabrication of a microfluidic chip integrated with permalloy micromagnets. The device was used with aptamer-modified magnetic beads (MBs) of various sizes to successfully separate lung cancer cells from a mixture of other cells. The overall separation efficiency was evaluated based on the ratios of cells in the different outlets and inlets of the chip. The results showed efficiencies ranging from 43.4% to 50.2% for MB sizes between 1.36 and 4.50 µm. Interestingly, efficiency slightly decreased as the size of the MBs increased, contrary to predictions. Further examination revealed that larger MBs exerted gravitational force on the cell-bound MBs at low flow rates, causing the targets to settle before reaching the main microchannel region. This was attributed to fluidic resistance caused by a size mismatch between the inlet tube and the microfluidic conduit. An increase in cell accumulation at the inlet was observed with larger MB sizes due to gravity. Therefore, the definition of effective separation efficiency was revised to exclude the effect of cell accumulation at the inlet. Effective separation efficiencies were found to be 71.6%, 76.4%, and 79.4% for MB sizes of 1.36, 3.00, and 4.50µm, respectively. The study concluded that larger MBs interacted more with the magnetic force, resulting in better separation. However, cells with smaller MBs were more likely to evade the magnetic force. The investigation provides valuable insights into isolating lung cancer cells using this method, with the potential for clinical application in cancer diagnosis and treatment.

Hydrothermally synthesized hierarchical Pom-Pom-like gadolinium modified tungsten oxide reinforced with rGO for annihilation of acetylsalicylic acid and crystal violet

Herein, novel hierarchical Gd@WO3 pom-pom-like microstructures have been prepared through the hydrothermal method and combined with RGO sheets (denoted as RGO/Gd@WO3). The synthesized materials, along with their analogs, were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), Mott-Schottky, current-voltage (I-V), electrochemical impedance spectroscopy (EIS), and optical analyses. The unique morphology of pom-pom-like microstructures allowed better interaction with pollutant molecules. Rare earth element (Gd3+) ions act as trapping species for photo-generated electrons and prolong the life span of reactive oxygen species (ROS). The high conductivity and flexible nature of RGO sheets provided fast transport of active species and provided stability to the photocatalytic material. To test the photocatalytic efficiency of RGO/Gd@WO3, crystal violet (CV) and acetylsalicylic acid (ASA) were used as model pollutants. Under a mimetic light source, RGO/Gd@WO3 exhibited maximum photodegradation of 98.8 % and 84 % for CV and ASA within 120 min of irradiation, respectively. Photocurrent, Mott-Schottky, and EIS experiments proved the production, effective separation, and transmission of photo-active species in the presence of RGO/Gd@WO3 as compared to Gd@WO3 and WO3. Given the electrochemical testing and optical analysis, the photocatalytic mechanism is anticipated for the high photocatalytic activity of RGO/Gd@WO3. The novel RGO/Gd@WO3 photocatalyst proved to be a superior photocatalytic material for the photodegradation of organic pollutants.

Research on the Hierarchical Separation of Rare Earths and Lithium from Rare Earth Molten Salt Slag

Lithium is an important non-renewable resource, and the study of the tiered separation of rare earths and lithium from rare earth molten salt slag is an important approach to solving the current global resource shortage. This article adopts a sulfuric acid leaching process and a lithium-containing solution iron lithium extraction separation process to recover lithium from rare earth molten salt slag. The method systematically investigates the impact of sulfuric acid concentration, liquid-to-solid ratio, leaching temperature, leaching time, pH, P507 concentration, phase ratio, extraction temperature, and extraction time on the lithium extraction effect and iron lithium separation effect in rare earth molten salt slag. The results show that under the conditions of a sulfuric acid concentration of 0.9 mol/L, a liquid-to-solid ratio of 8:1 mL/g, a leaching temperature of 70 °C, a leaching time of 90 min, a pH of 0.9, a P507 concentration of 50%, a phase ratio of 5:3, an extraction temperature of 30 °C, and an extraction time of 20 min, the lithium leaching rate reaches 97.8%, and the separation of iron and lithium is fully achieved. This method can efficiently recover the valuable element lithium from rare earth molten salt slag, which is of great significance for the subsequent preparation of lithium products and the realization of a closed-loop production of rare earth alloys by molten salt electrolysis.

Photocatalytic performance of Ni-Al LDH @Ag2XO4 (X = Cr, Mo, and W) nanocomposites under visible light

The contamination of water sources from dye discharge poses a significant environmental challenge. This study addresses this issue by synthesizing binary composites of Ni-Al LDH@Ag2XO4 (with X=Cr, Mo, and W). The main goal is to increase the separation of charge carriers to boost the efficiency of photocatalysis. The prepared samples were analyzed using FT-IR, FE-SEM, EDS, FE-TEM, XRD, UV–Vis DRS, and XPS techniques. Observations revealed a notable increase in MB degradation through photocatalysis under a 150 W mercury lamp in presence of Ni-Al LDH@Ag2CrO4 compared to individual samples, Ni-Al LDH and Ag2CrO4. At pH= 11, 0.5 g of Ni-Al LDH@Ag2CrO4 shows the highest activity (100 %) for the photodegradation of MB. The absorption edge of Ni-Al LDH@Ag2CrO4 (1.69 eV) has increased compared to that of Ni-Al LDH (2.53 eV), which increases the light absorption capacity. Moreover, the synergistic effect of Ni-Al LDH and Ag2CrO4 increases photocatalytic activity by reducing electron-hole recombination. The proposed Z-Scheme mechanism confirms effective charge separation and increased photocatalytic efficiency.

Optimizing Waste Separation in Traditional Minority Communities: A Game Theory Approach for Sustainable Municipal Waste Management

Successful solid-waste management relies heavily on citizen involvement and cooperation, particularly through effective source separation. By ensuring that waste is sorted correctly at source, costs are reduced, the quality of recycled products is improved, and waste handling becomes more efficient—resulting in significant cost savings for municipal authorities (MAs) and mitigating causes of air pollution, water pollution, and soil contamination.This study explores enhancing waste separation in local authorities populated by traditional minority groups through stakeholder cooperation. The aim is to improve economic, social, and environmental utilities while identifying the mechanism that best maximizes the well-being of all players involved.Employing mixed methods and game-theory tools, we conduct twenty-one in-depth interviews with local minority leaders to define the parameters of the service function. The utility functions of all players serve as a basis for game-theory modeling that allow us to identify Nash equilibria, compare their efficiency, and formulate the mechanism optimally.The results of the study show that when an influential local player fosters cooperation and trust among residents, effective waste separation is achieved, enhancing the well-being of all involved.

Deep eutectic supramolecular polymers based HPLC stationary phase: Green synthesis strategy and promising application prospects

BackgroundDeep eutectic solvents (DESs) have been widely and significantly applied in various fields due to their outstanding features such as low cost, easy preparation and good biodegradability. As novel derivatives of DESs, deep eutectic supramolecular polymers (DESPs) combine the macroscopic state of DESs with the covalent interactions of supramolecular polymers, which also possess the properties of DESs as multifunctional materials. Therefore, DESPs are believed to be promising candidates for separation science. However, there are no studies on the application of DESPs as stationary phases for HPLC analysis. ResultsIn this work, a novel DESP based HPLC stationary phase (Poly(DES)@SiO2) was developed for the first time through a green synthesis method by using DES as the polymerization monomer as well as the reaction medium. The results manifest that this novel Poly(DES)@SiO2 column can well interact with analytes through various mechanisms, and realize selective separation of a wide range of structurally similar hydrophilic/hydrophobic substances. More importantly, the separation of hydrophobic analytes on the Poly(DES)@SiO2 column is less time-consuming with fewer organic eluent, although the column efficiency is slightly lower than that of commercial C18 column. Furthermore, the Poly(DES)@SiO2 column exhibits excellent mechanical stability and satisfactory separation repeatability for steroid hormones. Therefore, a reliable method was established for detecting steroid hormones in actual samples with the recoveries ranging from 94.56 % to 103.84 %, which can meet the detection needs of commonly seen steroid hormones in food and the environment. SignificanceIn summary, this work provides some valuable theoretical references for the synthesis of new DESP based stationary phases through a green and facile strategy, and meanwhile, verifies the feasibility of DESP for effective HPLC separations. In addition, the promising application prospect of DESP based stationary phases in the analysis of complex samples has also been demonstrated, expanding the potential application of DES in separation science.

Enhanced bifunctional visible-light-driven photocatalytic production of H2 and H2O2 enabled by Ag-ZnIn2S4/C-In2O3 S-scheme heterojunction

Multifunctional photocatalysts are recognized as efficient solutions to complex energy and environmental challenges. In this study, we report the rationally-designed bifunctional photocatalysts of Ag-ZnIn2S4/C-In2O3 (AgZISCIO) with S-scheme heterojunction and defect engineering, for highly efficient production of both hydrogen and hydrogen peroxide production. The heterojunction is established by growing ZnIn2S4 (ZIS) nanosheets on MOF-derived C-doped In2O3 (CIO) nanorods, which favors the formation of built-in electric field, thus facilitating effective photogenerated charge separation. Moreover, by introducing Ag ions into ZIS lattice via a cation exchange reaction, abundant active sites would be created for inducing defects on the heterojunction surface, thereby enhancing the kinetics of oxidation–reduction processes. Under visible-light irradiation, the resultant AgZISCIO photocatalysts exhibit remarkable hydrogen and hydrogen peroxide production rates of 3.19 mmol·g−1·h−1 and 2.42 mmol·g−1·h−1, respectively, outperforming those of most In2O3-based photocatalysts reported recently. It is witnessed that the overall enhanced photocatalytic performance could be mainly attributed to the formed S-scheme heterojunction and defect creation for improved photogenerated charge separation and redox capabilities. This work underscores the importance of dual modulation of heterojunctions and defect engineering as an effective strategy for enhancing photocatalytic performance, providing some valuable insights for developing advanced multifunctional photocatalysts.

Lysine-regulated turing structure membrane via interfacial polymerization for enhanced Li+/Mg2+ separation

The development of advanced membranes with precise ion selectivity is essential for efficient Li+/Mg2+ separation. In this study, we synthesized a novel Lys-TMC membrane via a nucleophilic addition reaction between Lysine and trimesoyl chloride (TMC), yielding in a negatively charged surface interconnected by amide bonds. We systematically investigated the effects of varying Lys:TMC ratios on the membrane’s chemical structure, surface morphology, and ion separation performance. Our results revealed that the degree of cross-linking increases initially with the Lysine content, reaching an optimum at a Lys:TMC ratio of 10:1, where the membrane exhibited prominent Turing patterns on its surface. These patterns were critical for achieving effective ion separation. In contrast, excessive Lysine led to spontaneous polymerization, resulting in irregular ‘stone-like’ structures and the loss of Turing patterns. The optimally cross-linked Lys-TMC membrane displayed superior Li+/Mg2+ separation performance, highlighting the crucial role of controlled cross-linking and Turing structure formation in enhancing ion selectivity. This work provides a mechanistic understanding of the relationship between Turing structure formation and ion sieving performance, offering a promising strategy for designing advanced separation membranes.

Heterostructure of perovskite coupled graphitic carbon nitride for enhanced photodegradation under visible light

This study aimed to prepare and characterize LaFeO3 nanoparticles loaded graphitic carbon nitride (LFO/g-C3N4) photocatalyst and investigate the degradation of organic pollutants under UV and natural sunlight exposure. It is observed that LFO nanoparticles of an average size of about 67 nm were distributed on g-C3N4 sheets through chemical bonding owing to the formation of a composite. Compared to LFO and g-C3N4, composite has a good absorption ability to harvest more UV and visible light due to its large surface area and pore size. The photocatalytic studies revealed that the g-C3N4/LFO composite exhibits higher catalytic efficiency and stability for methylene blue (MB) degradation under UV and visible light. Under UV irradiation, the degradation efficiency of LFO, g-C3N4, and g-C3N4/LFO composite in synthetic wastewater was found to be around 50, 80 and 93 % with corresponding rate constants 0.05, 0.02, and 0.1 min−1 in 30 min, respectively. Under natural sunlight, the composite degraded 97 % of MB in 180 min with a rate constant of 0.016 min1. The higher photocatalytic activity of the composite was attributed to the interfacial charge transfer between LaFeO3 and g-C3N4, which are responsible for effective charge separation in the composite. Further, it has been investigated that singlet oxygen species (1O2) and hydroxyl radicals (•OH) are the main reactive species that contributed considerably to the complete degradation of MB. The nanocomposite was also demonstrated to be a stable catalyst and can be reused without any further modification.

Effective flotation separation of fluorite and barite with the environmentally friendly surfactant caprylhydroxamic acid

Effective flotation separation of fluorite and barite with the environmentally friendly surfactant caprylhydroxamic acid

Self-driven Te0.65Se0.35/GaAs SWIR photodiode with spectral response to 1.55 μm for broadband imaging and optical communication

Te-based photodetectors with the merits of low cost and CMOS-compatible fabrication process have been considered promising for broadband imaging applications. Nevertheless, the spectral response of reported devices under self-powered mode is generally limited to near-infrared wavelength below 1100 nm (corresponding to the bandgap of Si). This could be ascribed to the high room-temperature carrier density in Te and the ease of forming Type-I heterojunctions between Te and other semiconductors, which impede the effective generation and separation of photocarriers. This study reports the bandgap engineering of Te through Te-Se alloying and the fabrication of Te0.65Se0.35/Al2O3/GaAs photodiode with an extended response spectrum through ultraviolet to the short-wave infrared (SWIR) band of 1550 nm at zero bias. The effects of interface passivation on the photosensing properties were also investigated. The optimized heterojunction exhibits a pronounced photovoltaic response to 1342 nm (1550 nm) infrared light with an open-circuit voltage of ∼0.12 V (0.07 V). Particularly, the dark current density reaches a record low level of 0.1 nA/cm2 at 0 V bias, leading to a high on-off current ratio of 4.5×104 and detectivity of 1.1×107 Jones at room temperature for 1342 nm light. Self-powered UV-Vis-SWIR broadband imaging and optical communication are realized by leveraging the favorable device performance. Our work provides a frame of reference for exploring more Te1-xSex-based photodetectors. Meanwhile, it may be combined with well-developed semiconductor processing technologies for optoelectronics integration.