Excellent Separation Efficiency Research Articles

Swan feather-spired fluorine-free superhydrophobic self-cleaning cotton cloth with strong oil-water separation function

With the increasing demand of oil-water separation, superhydrophobic materials have garnered tremendous research attention due to their excellent oil-water separation efficiency. However, the biological toxicity and poor durability of fluorine-containing compounds in superhydrophobic materials severely restrict their application. In this work, inspired by the superhydrophobic/lipophilic swan feathers, we proposed a two-stage thiol-ene click reaction strategy to fabricate a fluorine-free superhydrophobic and super-lipophilic oil/water separation membrane (Cotton-S-PB-SiO2). Firstly, based on this thiol-ene click reaction, the rubber molecular chain 1,2-polybutadiene (1,2-PB) with low surface energy was coated with cotton fiber through chemical bonds. Subsequently, the coated cotton fiber was employed to establish chemical bonds with silica. The Cotton-S-PB-SiO2 possessed low surface energy and abundant micro-nano structures. Meanwhile, the Cotton-S-PB-SiO2 showed extremely high wettability selectivity to water and oil phases. The flux reached 44,554 L m−2 h−1, and the separation efficiency for immiscible oil/water mixtures was above 99.9 %. More remarkably, the Cotton-S-PB-SiO2 demonstrated excellent anti-fouling and operation stability even under some harsh environments such as strong acid, alkali, salt, etc. The prepared self-cleaning cotton cloth provides insights toward mild, low-cost and high-efficiency oil-water separation.

Flexible Z-scheme heterojunction membrane reactors for visible-light-driven antibiotic degradation and oil-water separation

This study fabricated PENS/TA/ZIF-67@Ag2S (PZA), a double self-cleaning network antifouling polymer membrane reactor, by the non-solvent-induced phase separation (NIPS) method. Due to the synergistic effect of the double self-cleaning structure, it showed an excellent separation efficiency of 99.65% and a high flux of 1198.011 L·m−2·h−1 in the separation of oil-in-water emulsion experiments. After eight cycles, Oil-water separation efficiency remains >99% recyclable. The Z-type heterogeneous conjunctival reactor we constructed has a high-efficiency degradation rate of 99.94% and a mineralization rate of 80.315% for sulfamethoxazole (SMX) within 120 min. From the results of mechanical properties, TGA and DSC, it can be seen that PZA has good strength, toughness and high temperature resistance. According to the experimental analysis of active substances, the active ingredients produced by PZA are •OH., h+, •O2–. Based on Density functional theory (DFT) calculations and intermediate analysis, sulfamethoxazole's active sites and degradation pathways (SMX) were explored. According to the Quantitative Structure-Activity Relationship (QSAR) of the Toxicity Estimation Software Tool (TEST), the toxicity of the intermediates produced during the degradation of SMX was predicted. This study provides a feasible strategy for fabricating Z-scheme metal-organic framework (MOF)-based polymer membrane reactors for efficient green antibiotic wastewater treatment and oil-water self-cleaning.

Fibrous ceramic membrane constructed by mullite whiskers for the treatment of oil‐in‐water emulsions

AbstractCeramic membranes with high porosity and excellent separation efficiency are necessary for the efficient treatment of large‐scale wastewaters. However, the conventional ceramic membranes are usually prepared by particles‐packing, which inhibits the advances of separation efficiency because of the low porosity and connectivity. Here, a fibrous ceramic membrane with mullite whiskers‐interlocked structure was prepared by gas‐solid reaction. The effects of aluminum fluoride (AlF3) on the formation and growth of mullite whiskers, and then the permeability and selectivity of the ceramic membranes were investigated. With the increase of AlF3 contents, the mullite phase evolved from needle‐like, rod‐like to flake‐like structure, thus the catalyst accelerated the growth of mullite whiskers in the diameter direction. For the ceramic membrane sintered at 1400°C, the porosity increased from 58% to 76% while the average pore sizes increased from 0.65 to 3.93 μm because of the whisker‐constructed structures. For the ceramic membrane sintered at 1450°C, the emulsion flux increased stably from 295 L/(m2·h) to 992 L/(m2·h) with the increase of trans‐membrane pressure, and the oil rejection exceeded 98%. Thus, this study provides a feasible strategy for the preparation of ceramic membranes with high porosity and excellent separation performances.

Intensification design of green crystallization separation: Process optimization and technology coupling

This work designs different process intensification trajectories in the layer melt crystallization (LMC) to improve the separation efficiency. Parameters of distribution coefficient, interfacial solute distribution factor, and mass transfer coefficient are proposed to figure out the intrinsic correlations of technical variables and target parameters. The first proposal strategy is the optimization of the operating curve, divided into cooling process regulation and temperature cycling strategy. Both techniques can eliminate the fine crystals, thus favoring the crystal growth and reducing the impurities' adsorption. Next is the incorporation of the stirring intensification technique into the LMC. The problem of burst nucleation is restricted significantly through the suitable design of the stirring parameters. At last, a coupling technique that combines suspension and LMC is designed. The crystal seeds generated from the suspension melt can flow into the tubular crystallizer and act as the sites for crystal growth. This coupling technique exhibits excellent separation efficiency and huge potential in industrial production. The proposals for the further development of the LMC technique are given.

A Photosensitizing Metal–Organic Framework as a Tandem Reaction Catalyst for Primary Alcohols from Terminal Alkenes and Alkynes

AbstractOwing to the wide and growing demand for primary alcohols, the development of efficient catalysts with high regioselectivity remains a worthwhile pursuit. However, according to Markovnikov's rule, it is a challenge to obtain primary alcohols with high yields and regioselectivity from terminal alkenes or alkynes. Herein, we report the synthesis of a photosensitizing two‐dimensional (2D) metal–organic framework (MOF) from cyclic trinuclear copper(I) units (Cu‐CTUs) and a boron dipyrro‐methene (Bodipy) ligand. The MOF features broadband light absorption, excellent photoinduced charge separation efficiency, and photochemical properties. By integrating the copper‐catalyzed hydroboration and photocatalyzed aerobic oxidation, it can catalyze terminal alkenes and alkynes to produce primary alcohols via a one‐pot tandem reaction with excellent regioselectivity, good overall yields in two‐step reactions (up to 85 %), broad substrate compatibility (32 examples) and good reusability under mild conditions.

A Photosensitizing Metal-Organic Framework as a Tandem Reaction Catalyst for Primary Alcohols from Terminal Alkene and Alkyne.

Due to the wide and growing demand for primary alcohols, the development of efficient catalysts with high regioselectivity remains a worthwhile pursuit. However, according to the Markovnikov's rule, it is challenge to obtain primary alcohols with high yields and regioselectivity from terminal alkenes or alkynes. Herein, we reported the synthesis of a photosensitizing two-dimensional (2D) metal-organic framework (MOF) from cyclic trinuclear copper(I) units (Cu-CTUs) and boron dipyrro-methene (Bodipy) ligand. The MOF features broadband light absorption, excellent photoinduced charge separation efficiency, and photochemical properties. By integrating the copper-catalyzed hydroboration and photocatalyzed aerobic oxidation, it can catalyze terminal alkenes and alkynes to produce primary alcohols via one-pot tandem reaction with excellent regioselectivity, good overall yields in two-step reactions (up to 85%), broad substrate compatibility (32 examples) and good reusability under mild conditions.

New insight into ZnO@ZIFs composite: an efficient photocatalyst with boosted light response ability and stability for CO2 reduction.

One of the main causes of climate change and energy exhaustion is the excessive use of fossil fuels. Photocatalytic carbon dioxide (CO2) reduction technology uses inexhaustible sunlight to directly convert CO2 into value-added chemicals or fuels not only solving the problem of greenhouse effect but also alleviating the shortage of fossil energy. In this work, a well-integrated photocatalyst is synthesized through growing zeolitic imidazolate frameworks (ZIFs) with different metal nodes on ZnO nanofiber (NFs) for CO2 reduction. One-dimensional (1D) ZnO NFs have better CO2 conversion efficiency due to the high surface-to-volume ratio and low light reflectivity. 1D nanomaterials with superior aspect ratios can be assembled into free-standing flexible membranes. In addition, it has been found that ZIFs nanomaterials with bimetallic nodes not only have better CO2 reduction capabilities but also exhibit superior thermal and water stability. The photocatalytic CO2 conversion efficiency and selectivity of ZnO@ZCZIF are shown to be significantly enhanced which can be attribute to the strong CO2 adsorption/activation, efficient light capture, excellent electron-hole pair separation efficiency, and specific metal Lewis sites. This work provides insights into the rational construction of well-integrated composite materials to improve the photocatalytic carbon dioxide reduction performance.

Functionalized waterworks sludge particles as column packing materials for simultaneous Cr (Ⅵ) removal and oil separation

Highly efficient and low-cost treatment of waterworks sludge and oil-containing Cr (Ⅵ) wastewater in one way is a challenge in the field of water treatment. Herein, a waste-control-waste strategy was proposed to fabricate a functionalized waterworks sludge-based Zn–Al layer double oxides material (Zn–Al LDOs/WS) for simultaneously separating Cr (Ⅵ) and oil. During the column separation process, due to the superhydrophilic/underwater superoleophobicity of Zn–Al LDOs/WS and the memory effect of LDHs, Cr (Ⅵ) will be stabled in the filter layer by electrostatic attraction and surface complexation between the Zn–Al LDHs/WS and Cr (Ⅵ), and the small oil droplets will coalesce into big oil droplets that be blocked in the separation column, thus achieving simultaneous separation. The Zn–Al LDOs/WS with hierarchical porous structure exhibit excellent simultaneous separation efficiency for Cr (Ⅵ) (99.69%) and oil (99.24%), and high separation flux (1063 L m−2 h−1). In addition, the separation efficiency and flux can be flexibly controlled by adjusting the filter layer thickness. The Zn–Al LDOs/WS also display strong acid and alkali resistance (pH 1–11), wide applicability range of initial Cr (Ⅵ) concentration (5–200 mg/L) and outstanding anti-interfering ion ability (Cl−, HCO3−, SO42−, NO3−, H2PO4−, CO32− and F−) in Cr (Ⅵ) and oil separation. Therefore, this work can not only improve treatment efficiency and save costs through simultaneous separation, effectively treat solid waste and complex wastewater, but also provide a theoretical basis for the design and application of functional materials derived from waste sludge.

Effectively recovering catechin compounds in the removal of caffeine from tea polyphenol extract by using hydrophobically modified collagen fiber

Previous research had proved that collagen fiber can be used as separation material for removing caffeine from tea polyphenol extract effectively. But the recovery rate of catechin compounds from collagen fiber column was quite low by using water and ethanol as eluent because of excessively strong hydrogen bond interaction between collagen fiber and polyphenols. To solve the problem, collagen fiber was hydrophobically modified in this work by using silane coupling agents with alkyl chains (butyl, octyl, dodecyl and octadecyl). FT-IR, DSC, SEM and EDS Mapping proved the successful grafting of alkyl chains on collagen fiber, leading to the significantly enhanced hydrophobicity of collagen fiber. Static adsorption showed that the adsorption capacity of EGCG decreased when the grafted alkyl chain length increased mainly relying on the weakened hydrogen bond interaction. Dynamic adsorption and elution behavior also indicated less retention capacity of EGCG on collagen fiber with higher hydrophobicity. In column separation of simulated tea polyphenol extract containing caffeine and catechin compounds, the collagen fiber grafted with octadecyls (CF(C18)) presented excellent separation efficiency for caffeine and catechin compounds, and simultaneously the catechin compounds were highly recovered. The recovery rates of EGC and EGCG were 2–7 times higher than those separated by pristine collagen fiber column and glutaradehyde crosslinked collagen fiber column developed in our previous work. In the reusing round of CF(C18) column, the chromatogram was almost the same as the first round, showing excellent reusability. In fact, the separation performance of CF(C18) to caffeine and catechin compounds was comprehensively superior to Sephadex LH-20, presenting great practical application potential in effectively removing caffeine from tea polyphenol extract and recovering catechin compounds.

Macrocycle Self-Assembly Hydrogel for High-Efficient Oil-Water Separation.

Supramolecular hydrogels involved macrocycles have been explored widely in recent years, but it remains challenging to develop hydrogel based on solitary macrocycle with super gelation capability. Here, the construction of lantern[33 ]arene-based hydrogel with low critical gelation concentration (0.05 wt%), which can be used for efficient oil-water separation, is reported. The lantern[33 ]arenes self-assemble into hydrogen-bonded organic nanoribbons, which intertwine into entangled fibers to form hydrogel. This hydrogel which exhibits reversible pH-responsiveness characteristics can be coated on stainless-steel mesh by in situ sol-gel transformation. The resultant mesh exhibits excellent oil-water separation efficiency (>99%) and flux (>6 × 104 L m-2 h-1 ). This lantern[33 ]arene-based hydrogel not only sheds additional light on the gelation mechanisms for supramolecular hydrogels, but also extends the application of macrocycle-based hydrogels as functional interfacial materials.

Durable Nanofiber-Based Membrane with Efficient and Consistent Performance for Oil/Saltwater Separation

There is a large amount of oil-contaminated wastewater caused by oil/gas production and marine oil spills. It is still a major challenge for the development of oil/water separating membranes that have excellent separation efficiency, can withstand saline environments, and have long-term durability. We present a new membrane made of ultralong titanate nanofibers (TNF) (with diameter of 200 nm and length of 60 µm) and carbon nanofibers (CNF) (with a diameter of 150 nm and length of 50 µm) for efficient and consistent oil/saltwater separation. The intertwined structure of titanate and carbon nanofibers is critical to ensuring a high mechanical strength and durability for the new membrane. The carbon nanofiber works as a scaffold in this membrane to maintain mechanical integrity during multiple cycles of reuses, which is an important merit for its practical applications. The ultralong titanate nanofibers work as functional component to provide high hydrophilicity of the membrane. The new membrane has an oil/water separation efficiency of more than 99%, an oil content in treated effluent that is lower than US environmental discharge standards (42 ppm), and a high water flux of 1520 LMH/bar, due to its excellent superhydrophilicity and inter-connected pore structure. The new membrane also exhibits outstanding durability in a variety of salinity environments, as well as good resistance to oil fouling. This new type of membrane has a high potential for industrial application in treating oily wastewater due to its excellent environmental durability, oil-fouling resistance, high separation efficiency, and easy scalability.

Porous ZnS/MXene Ti3C2 nanocomposite with a terrific photocatalytic ability for tetracycline hydrochloride degradation

Porous ZnS/MXene Ti3C2 nanocomposite was synthesized by one-step hydrothermal method. MXene Ti3C2 with a unique layered structure was used as cocatalyst. ZnS/MXene Ti3C2 nanocomposite was utilized for photocatalytic degradation of tetracycline hydrochloride (TCH). The photodegradation efficiency of TCH were 96% during 60 min under simulated sunlight irradiation. The opened 2D space of MXene Ti3C2 was suitable for ZnS nanoparticles dispersion, which obtained a mesoporous nanocomposite with plenty of heterostructure interfaces. At the same time, the good electron transfer efficiency of MXene Ti3C2 could also provide the high-speed channel through the numerous intimate heterostructure interfaces. Meanwhile, ZnS/MXene Ti3C2 nanocomposite could still maintain a good stability after three cycles. It was significant that ZnS/MXene Ti3C2 nanocomposite achieved an excellent separation efficiency of photogenerated carriers via constructing heterojunction. It proved that porous ZnS/MXene Ti3C2 nanocomposite as a mesoporous superior photocatalyst was an effective and potential photocatalyst for antibiotic degradation.

Superoleophobic Polyketone Nanofiber Membranes for Efficient Separation of Oil/water Emulsions

AbstractElectrospun nanofiber membranes derived from polyketone (PK) are precisely fabricated to exhibit an excellent separation efficiency for oil/water emulsions. The fiber diameter and pore size of the membrane are controlled by introducing NaOH to the precursor solution prior to electrospinning. The surface properties of the nanofibers are then controlled by the removal of NaOH with water and reduction of functional groups with sodium borohydride (NaBH4) to exhibit an air‐water superhydrophilicity and underwater superoleophobicity. This surface conversion process is easily monitored by the water contact angle and the underwater oil contact angle. Oil/water emulsions, including toluene, soybean oil, and hexadecane are filtered through the membranes to examine their separation efficiency and flux using total organic carbon and UV‐Vis measurements. The optimized membrane exhibits the minimum 97 % separation efficiency for all three oil/water emulsions and recyclability without notably losing its flux under gravity‐driven filtration conditions.

Microwave-assisted construction of Bi2MoO6/g-C3N4 heterostructure for boosting photocatalytic CO2 conversion

Photocatalytic CO2 reduction can simultaneously alleviate the energy crisis and solve environmental issues. Nevertheless, it is still challenging for designing photocatalysts with efficient carrier mobility in rational. Herein, the Bi2MoO6/g-C3N4 (BMO/CN) heterostructure was constructed through a microwave-assisted which could enhance the construction of two-dimensional and two-dimensional (2D/2D) structures. The 2D/2D BMO/CN heterojunction possessed excellent charge separation efficiency which exhibited superior performance on photocatalytic CO2 reduction. It was shown by the characterization that the (131) surface of Bi2MoO6 was constructed with the (100) surface of g-C3N4. The work functions of Bi2MoO6 and g-C3N4 were determined to be 4.57 and 4.22 eV, respectively, which suggested the type-II heterojunction was formed. The formation of CO and CH3OH over the optimized BMO/CN-30% catalyst reached 2.44 and 3.61 µmol⋅g−1⋅h−1, respectively. The immediate products of HCO3- were observed within in-situ FT-IR to further certify the evolution of CH3OH. This work highlighted a microwave-assisted strategy to build a heterojunction structure for enhancing photoreduction CO2.

Environment-Friendly superhydrophobic sponge for highly efficient Oil/Water separation and microplastic removal

The pollution of water resources by oils and microplastics is a significant global issue affecting the environment and human health. However, developing a sustainable multifunctional adsorption material to remove multiple pollutants has always been a challenge. Herein, an eco-friendly superhydrophobic polyurethane sponge was developed using polydimethylsiloxane (PDMS) and dehydroabietic acid grafted Al2O3 nanoparticles by dip-coating technique. The green dehydroabietic acid has strong hydrophobicity, which can make the coated sponge have excellent separation of oil/water mixtures or emulsions and has a high oil absorption capacity (20–55 g/g) for various kinds of oils. Continuous oil/water separation was also achieved by gravity-driven or with the assistance of peristaltic pump. After 10 separation cycles, the coated sponge still exhibits excellent separation efficiency (greater than 97%) due to its outstanding mechanical durability and compressive performance. Moreover, various kinds of microplastics could be efficient captured from the aqueous solution at a higher rate using the coated sponge, which is mainly due to the capillary force of the coated sponge and the non-covalent force and conjugates between PDMS and microplastics. This work provides a new strategy to fabricate a sustainable multifunctional sponge for oily wastewater and microplastics and shows the great potential for large-scale practical application.

Promoting photocatalytic performance of TiO2 nanomaterials by structural and electronic modulation

Titanium dioxide (TiO2) possessing excellent visible light response and high separation efficiency of charges without sacrificing its redox ability predicts significant opportunities for an efficient solar energy conversion system. Herein, novel TiO2 nanomaterials with upward-shifted conduction bands and tunable crystal phases were prepared by a lysine doping method. Lysine-doped TiO2 (LDT) showed enhanced reduction potential, efficient charge separation, and improved visible-light absorption. As photocatalysts, LDTs exhibited boosting photocatalytic ability both in light-to-chemical conversion and in refractory pollutant degradation. They can convert visible light to chemical energy and store in nicotinamide adenine dinucleotide (NADH) independent of any electron mediator with a yield of ca. 90%, far beyond that of the undoped TiO2 (13%). As for the refractory pollutant removal, compared to the negligible effect over the undoped TiO2 and commercial titania P25, lysine doping in TiO2 performs as a reaction switch to enable the photodegradation of 4-chlorophenol (4-CP) to proceed. More than 80% of 4-CP was removed with a kinetic constant of 0.8801 h−1. This work presents a distinctive strategy to precisely control the structure of TiO2 nanomaterials and provides a fresh insight into the structural and electronic modulation to promote their photocatalytic performance.

Smart and durable pH-responsive superhydrophobic fabrics with switchable surface wettability for high-efficiency and complex oil/water separation

The oily wastewater has posed a great threat to the environment and human health, and the oil-water mixture is complex and diverse. Therefore, it is crucial to develop a smart and efficient oil/water separation material. In this paper, random polymers containing carboxyl groups were synthesized for surface-modifying hydrophilic SiO2 nanoparticles. Polydimethylsiloxane (PDMS) was then used as the adhesive to fix the modified SiO2 nanoparticles firmly on the fabric surface endowing the fabric with a robust hydrophobic effect. The modified SiO2 nanoparticles not only made the fabric obtain a rough structure but also caused the fabric to have the effect of switchable wettability under the stimulation of pH. In addition, the prepared fabric maintained good mechanical durability and chemical stability after the mechanical abrasion, ultraviolet irradiation, and organic solvent treatment. Interestingly, under the stimulation of pH, the smart fabric could controllably separate different oil/water mixtures (including heavy oil/water and light oil/water) with excellent separation efficiency and high flux even after 20 cycles of separation process. Meanwhile, the pH-responsive fabric material successfully separated light oil/water/heavy oil three-phase oil/water mixture and different kinds of emulsions. Therefore, the prepared pH-responsive superwetting fabric has a broad application prospect in the field of dealing with complex oil/water mixing systems.

Interfacial charge separation of nickel tungstate anchored on g-C3N4 heterojunction stimulates visible-light driven direct Z-scheme photoelectrochemical hydrogen evolution

Active photocathodes are required for the photo(electro)chemical hydrogen evolution reaction (PEC-HER) in a highly efficient solar-to-hydrogen fuel conversion process aided by solar assisted water splitting. Here, we used a simple one-pot solvothermal method to prepare NiWO4/g-C3N4 nanocomposites for PEC-HER using low-cost, metal-free photocatalysts such as graphitic carbon nitride (g-C3N4) and nickel tungstate (NiWO4). Subsequently, the physicochemical and optoelectronic nature of the as-synthesized materials were studied by spectroscopic methods. As part of a direct Z-scheme heterogeneous mechanism, the photoactive module, g-C3N4 was blended with NiWO4 in varying ratios to enhance the efficiency of charge separation in PEC-HER. As expected, the established NiWO4/g-C3N4 nanocomposite demonstrates an enhanced photo(electro)catalytic activities compared to the single components. It is firmly due to the presence of intimate interfacial interaction between g-C3N4 and NiWO4, which further supports the existence of electrons in the conduction band of g-C3N4 and holes in the valence band of NiWO4. The prepared NiWO4/g-C3N4 nanocomposite with 15 wt% of g-C3N4 showed an enhanced photocurrent density of 167.81 mA cm−2, which is higher than that of other prepared photo(electro)catalysts and confirms its excellent charge separation efficiency as well as very low electron-hole recombination rate. Besides, the photoelectrochemical activities of the prepared materials were analysed through a PEC-HER, revealing that the developed NiWO4/g-C3N4 nanocomposite as photocathode requires a low overpotential of 0.048 V to reach the current density of 10 mA cm−2 and a Tafel slope of 43 mV dec−1, indicating the superiority of the photo(electro)catalyst. In addition, the NiWO4/g-C3N4 photocathode exhibits excellent performance for PEC-HER with higher stability.

In-situ growth of robust and superhydrophilic nano-skin on electrospun Janus nanofibrous membrane for oil/water emulsions separation

It is difficult for composite fibrous membranes to achieve up to 99.5% separation efficiency for oil/water emulsions under cycling separation. Herein, a simple method is developed to in-situ grow surperhydrophilic nanocoating on a single electrospun polyvinylidene fluoride (PVDF) fiber surface for fabricating asymmetric wettable Janus PVDF fibrous membranes. Particularly, polysaccharide fluids with zwitterionic polymer chains are generated from the nanofiber subsurface in an inside-out way during the electrospinning process, forming the robust superhydrophilic nanocoating (<5°) under a synergistic effect of both the electric field force and self-migration feature of N-carboxymethyl chitosan fluids (CMCfs). Benefiting from opposite wettability of the PVDF Janus membrane, the results show that the as-prepared Janus membranes with asymmetrical wettability exhibit excellent separation efficiency (S/E) (>99.5 %), a high flux (up to 4325 L m−2 h−1 bar−1), antibacterial activity (>99%) and antifoul properties. Moreover, the obtained Janus membranes own surprising flux cycling stability and retained 99.5% separation efficiency after 12 cycles without any treatment, indicating that the multi-arm polysaccharide fluids acted as the water channel in such membrane and accelerated the flow of water molecules. The Janus PVDF composite membranes have potential applications for oily wastewater treatment and water purification in the future.

Visible-light-induced activation of peroxymonosulfate by N-CuMe2Pc nanorods decorated on siloxene sheets for degradation of Rhodamine B

Exploring highly efficient photocatalysts is critical for integration of photocatalysis and peroxymonosulfate (PMS) activation. Herein, N-CuMe2Pc/Siloxene nanocomposites were fabricated by immobilizing the N-CuMe2Pc nanorods onto the surface of ultrathin Siloxene nanosheets to activate PMS for efficient photodegradation of (Rhodamine B) RhB. The prepared nanocomposites possess excellent photoabsorption capability and separation efficiency of photogenerated carriers. As expected, the nanocomposites exhibit superior catalytic activity and stability in PMS activation toward RhB photodegradation with highest removal efficiency of 95.3%, which is higher than that of Siloxene and N-CuMe2Pc. The active species in photocatalytic process and degradation pathways were determined through radical quenching studies. The reaction mechanism was systematically illustrated based on the intermediates detection and band structures. This study provides an experimental basis for further understanding of the photocatalytic oxidation behavior of metal phthalocyanine modified two-dimensional semiconductor materials, and is helpful to promote the research and application of photocatalytic degradation of refractory organic pollutants.