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In this work, we proposed a new hybrid of Pd nanoparticles dispersed on CeO2 nanotubes (Pd NPs/CeO2 NTs) with synergistically enhanced peroxidase-like activity for the visual detection of sulfhydryl compounds. In comparison with individual Pd NPs and CeO2 NTs, the Pd NPs/CeO2 NTs hybrid exhibited a synergy effect to trigger the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to its blue product TMBox mediated by H2O2. It was further demonstrated that the improved activity observed in Pd NPs/CeO2 NTs originated from the strong interplays between Pd NPs and CeO2 NTs, which could significantly increase the Ce3+/Ce4+ ratio. Besides, sulfhydryl compounds were found to have the capacity to suppress the color reaction of TMB + H2O2 catalyzed by the Pd NPs/CeO2 NTs nanozyme at a low level. Based on this principle, mercaptoacetic acid in the concentration range of 66–400 nM could be linearly determined. Similarly, sulfhydryl-containing amino acid (cysteine) and its derivative (glutathione) in the linear scope of 6–40 nM were also detected, providing a detection limit down to 2.9 and 11.3 nM, respectively.

In analytical science, it is always of great scientific and practical significances to explore convenient, rapid, and reliable methods/devices to trace the H2O2 level in various matrices. Herein, we fabricated a ready-to-use paper-based chemosensor by using mesoporous carbon-dispersed Pd nanoparticles (Pd NPs/meso-C) as a promising peroxidase mimic for the visual determination of H2O2. Thanks to the large exposed surface of the meso-C support and the highly dispersed active Pd NPs, the synthesized Pd NPs/meso-C exhibited favorable catalytic performance to trigger the chromogenic reaction of colorless TMB to blue TMBox mediated by H2O2, providing a Kcat of 326.67 s−1 for H2O2 and 0.55 s−1 for TMB, larger than the bare Pd NPs and even comparable to the activity of natural horse radish peroxidase. As demonstrated, this principle could be employed to colorimetrically detect H2O2 in the linear scope of 5–300 μM. By simply immobilizing the Pd NPs/meso-C mimic and the TMB substrate onto a common filter paper, ready-to-use paper-based sensors were further prepared. By combining these test strips with a smartphone and an easy-to-access color-scanning APP together, the integrated platform could be used for the quantitative analysis of H2O2 with advantages of simple operation, fast response, low cost, and good selectivity and repeatability. Furthermore, reliable sensing of the target in milk matrices suggested great promise of the integrated platform in practical applications.

Molecularly imprinted fluorescence sensors have shown great promise in environmental or biological monitoring and due to its high stability, selectivity and sensitivity. In this study, a fluorescence surface-imprinted sensor (SiO2-AF@MIPs) towards tetracycline (TC) was successfully prepared to address the shortcomings in current molecularly imprinted fluorescent sensor, such as slow response, limited detection and deteriorated performance in real complex samples. Benefited from the thin surface-imprinting layer, the SiO2-AF@MIPs sensors showed higher sensitivity (LOD low to 4.26 nM), rapid detection rate, reusable performance and excellent selectivity over several target competitors. Furthermore, the fluorescence sensor could efficiently detect TC in real biological samples, including tetracycline hydrochloride injection, human serum and swine urine. These results clearly demonstrated the potential value of this smart sensor nanomaterial in environmental monitoring and biological diagnosis.

A simple yet efficient strategy is urgently desired to prepare smart metal-organic framework nanocomposite for highly selective capture and separation of natural flavone from complex extraction samples. In this study, novel hydrophilic magnetic borate-functionalized metal-organic framework nanocomposites (Fe3O4@PDA@BA-MOFs) were designed and synthesized for selective enrichment of cis-diol containing luteolin (LTL). The well-known solvothermal reaction was adopted to prepare the magnetic core Fe3O4, followed by self-polymerization of dopamine, to create the polydopamine (PDA) onto Fe3O4. Thanks to the hydroxyl and amino groups of PDA, Zn2 + was easily adhered to the surface, taking advantage of magnetic response to fabricate the Fe3O4@PDA@BA-MOFs by layer-by-layer assembly strategy with borate ligand (5-boronobenzene-1,3-dicarboxylic acid). The ultrahigh surface area, uniform morphology, high saturation magnetization, excellent hydrophilicity and strong magnetic responsiveness of the as-prerared smart porous adsorbent (i.e. Fe3O4@PDA@BA-MOFs) were highly confirmed by the characterizations. Based on the batch mode experiments, Fe3O4@PDA@BA-MOFs showed high selectivity, obvious binding kinetics, large adsorption capacity, and excellent reusability (above 91.23% at least six repeated adsorption-desorption cycles). Moreover, pH-responsive capture and release mechanism based on the boronic acid affinity was proved, and Fe3O4@PDA@BA-MOFs would be good candidates for the enrichment and purification of the LTL.

Fabrication of chitosan-based composites without tedious procedures and significant biological hazard arising from using glutaraldehyde in the Schiff base reaction is highly needed. An environmentally friendly chitosan tablet is fabricated using Fe3+-mediated chitosan complexes via metallo-supramolecular chemistry. The structural properties of the material were investigated by SEM, FTIR, Raman and XRD, and the results indicated that Fe3+ could chelate with chitosan via a “hide-and-seek” strategy to form well crosslinked polymer network. Moreover, the swelling behavior of the chitosan tablet showed that maximum swell ability achieved at pH 7.4. In addition, the chitosan tablet displayed pH-stimulated release properties, and its construct (i.e. chitosan-Fe3+ complexes) was released efficiently at pH 1.0. Furthermore, the cytotoxicity experiments confirmed that chitosan tablet was compatible with human cell. Based on these results, we demonstrate here that the obtained chitosan tablet would be an oral iron supplementation potentially for treatment of iron deficiency anemia (IDA).

Nanomaterials with enzyme-like characteristics (nanozymes) are an emerging alternative of traditional bioenzymes that holds great promise in a variety of fields. The activity and efficiency of most current nanozymes, however, are lower than those of natural enzymes, which will inevitably hinder their wider applications. Thus, the development of new nanozymes with favorable catalytic properties is urgently desired. In this work, we reported a coral-structured bimetallic PdCu nanozyme that exhibited enhanced peroxidase activity and efficiency. The coral-like nanozyme fabricated by a microwave-assisted wet-chemical method was composed of assembled PdCu branches. In a comparison with pure Pd, the bimetallic PdCu had an enhanced ability to catalyze the reaction of colorless tetramethylbenzidine (TMB) to its blue oxide (TMBox) in the presence of hydrogen peroxide (H2O2). X-ray photoelectron spectroscopy and theoretical calculation indicated that the insertion of Cu atoms into the Pd lattice would increase the P...

TiO2 nanoparticles (NPs) could adversely impact aquatic ecosystems. However, the aggregation of these NPs could attenuate this effect. In this work, the biological effects of TiO2 NPs on a marine microalgae Isochrysis galbana were investigated. The aggregation kinetics of TiO2 NPs under different conditions was also investigated to determine and understand these effects. Results showed that, though TiO2 NPs had no obvious impact on the size and reproducibility of algal cells under testing conditions, they caused a negative effect on algal chlorophyll, which led to a reduction in photosynthesis. Furthermore, fast aggregation of TiO2 NPs occurred under all conditions, especially at the pH close to the pHzpc. Increasing ionic strength and NP concentration also enhanced the aggregation rate. The aggregation and the following sedimentation of TiO2 NPs reduced their adverse effects on I. galbana.

In this work, we demonstrated a nano-decorated porous impedance electrode sensor for efficient capture, rapid killing and ultrasensitive detection of bacteria. The multi-functional sensor was prepared by a facile sonochemical method via in situ deposition of antibacterial prickly Zn-CuO nanoparticles and graphene oxide (GO) nanosheets on a Ni porous electrode. Due to the surface burr-like nanostructures, the nano-decorated impedance sensor exhibited very good bacterial-capture efficiency (70 - 80% in 20min) even at a low concentration of 50 CFU mL-1, rapid antibacterial rate (100% killing in 30min) and high detection sensitivity (as low as 10 CFU mL-1). More importantly, the nano-decorated sensor has proven to be highly effective in quantitative detection of bacteria in a biological sample, for example, a rat blood sample spiked with E. coli. Despite the complexity of blood, the sensor still exhibited excellent detection precision within 30min at bacteria concentrations ranging from 10 - 105 CFU mL-1. The simplicity, rapidity, sensitivity, practicability and multifunctionality of this impedance sensor would greatly facilitate applications in portable medical devices for on-the-spot diagnosis and even the possibility for simultaneous therapy of diseases caused by bacterial infections.

Prussian blue (PB) is widely used as an artificial peroxidase for electrochemical biosensors, yet it is rarely utilized in photometric detection because of its intrinsic color interference. Herein, we proposed a new strategy, growing PB on common carbon cloth (CC), to obtain a monolithic peroxidase mimic with no background interference for colorimetric detection. Through a one-pot two-step electrodeposition procedure, a robust PB film composed of compactly assembled cubes was coated on CC surface. Since the active PB is immobilized on a bulk substrate (not like previous nanozymes that were dispersed in solution), the color interference from PB itself is efficiently avoided. In addition, the obtained monolithic nanozyme can be put into and taken out from reaction systems expediently and promptly with just a tiny pair of tweezers, which makes it possible for on-demand detection. As demonstrated, the PB-based nanozyme exhibited excellent peroxidase-like activity and could trigger the color reaction of 3,3′5,5′-tetramethylbenzidine in the presence of H 2 O 2 , leading to a detection limit of as low as 1.7 μM for H 2 O 2 sensing. A uric acid (UA) colorimetric assay was further established by incorporating the PB/CC peroxidase mimic with natural uricase, providing a linear absorbance response in the analyte concentration scope of 10–700 μM. Reliable analysis of UA in human serum and urine verified the practicability of the fabricated assay.

In this work, a facile synthesis of ceria and sulfated zirconia (SZ) incorporated SBA-15 catalyst was conducted. The supported SZ reveals promising Bronsted/Lewis acid and relatively low base strength, and the base strength of the catalyst is significantly enhanced by introducing highly dispersed ceria into the network of SZ incorporated SBA-15. Systematic study of catalyst activities were carried out in iPrOH/DMSO solvent conversion of glucose to 5-hydroxymethylfurfural (HMF). It is found that the isomerization process of glucose to fructose was promoted by coexisting base and Lewis acid sites, and the dehydration reaction of reactively formed fructose to HMF was directed by Bronsted acid sites. Up to 66.5% HMF yield and 70.8% selectivity can be obtained in a 90 vol % iPrOH-mediated DMSO solvent. Through the reaction system developed in this paper, use of a large amount of environmentally hazardous solvent can be avoided, and a new method of large-scale economically viable processes for biomass conservat...

Smart absorbents with high affinity to specific toxicant, especially with multi-affinity to both metal ions and organic pollutants, are very appealing for the treatment of heavy metal and organic co-contaminated water. A versatile strategy based on Pickering high internal phase emulsions (HIPEs) and controllable pore-filled technique was reported to fabricate molecule and ion dual-imprinted polymer adsorbent (M/I-DIPA). 2-Bromoisobutyryl bromide (BIBB)-modified silica nanoparticles (MSPs) were firstly employed to form Pickering HIPEs template, and then it was used to prepare λ-cyhalothrin (LC)-imprinted polymer foam (MIPA). Secondly, surface-initiated atom transfer radical polymerization (SI-ATRP) was adopted to controllably produce Cu(II)-imprinted adsorbent onto the MSPs which firmly “locked” in the MIPA shell. As-prepared M/I-DIPA effectively avoids the burying of recognition sites in a secondary imprinting process, and possesses highly permeable macroporous morphology. In batch mode experiments, M/I-DIPA exhibits fast binding kinetics (i.e. 60 min), and the maximum monolayer adsorption amount from Langmuir model for LC and Cu(II) are 120.8 µmol g −1 and 101.7 µmol g −1 at 35 °C, respectively, indicating this strategy makes the defined imprinted cavities well protected in twice imprinting steps. Moreover, LC and Cu(II) have both higher imprinting factor α (about two times) than the other structural analogues, and the excellent selectivity coefficient β in multi solute system also demonstrates the preferential affinity to templates (i.e. LC and Cu(II)) due to a good imprinting effect. The loss in adsorption amounts of M/I-DIPA for LC and Cu(II) at 120 min after four regeneration cycles are 7.295% and 13.05%, respectively, illustrating good retention of the activity of M/I-DIPA.

With the increasing market demands of lithium (Li) and rubidium (Rb) around the world, the shortage of Li and Rb seriously restrict the further development of relevant industries. In this work, we report a superior lithium/rubidium imprinted hierarchical porous silica (Li/Rb-IHPS) for the simultaneous selective extraction of lithium and rubidium from aqueous solution. Li/Rb-IHPS was prepared by ion imprinting technology (IIT) by using 12-crown-4 (12-C-4) and N-[(3-Trimethoxysilyl) propyl] ethylendiamine triacetic acid trisodium salt (TMS-EDTA) as functional monomers. The structure, thermal property and surface functional groups of as-prepared Li/Rb-IHPS material were characterized by Fourier infrared spectroscopy (FT-IR), elemental analysis, thermogravimetric analyzer (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nitrogen adsorption-desorption. The results indicate that the as-prepared material has a hierarchical mesoporous structure (peak pore at ca. 3–4 nm and 12–15 nm) with high specific surface area (BET) (242.47 m2 g−1). The adsorption experiments show that Li/Rb-IHPS has a high adsorption capacity for Li+ (166 μg g−1) and Rb+ (141 μg g−1). The adsorption process can be described by pseudo-second-order kinetic model, suggesting that the adsorption for Li+ and Rb+ is controlled by chemical adsorption. And the Langmuir isotherm model can well fit the experimental data, illustrating that the adsorption process are all monolayer adsorption reactions. Additionally, the adsorption selectivity and reusability measurements were also investigated. Compared with some ions such as Na+, K+, Mg2+ and Cs+, Li/Rb-IHPS material shows excellent adsorption selectivity for Li+ and Rb+. After five cycles, the Li/Rb-IHPS material remains high adsorption capacity for Li+ (94%) and Rb+ (93%). The obtained results indicate that Li/Rb-IHPS can be used to extract the lithium and rubidium from oceans and lakes selectively, rapidly, and environmentally.

A facile strategy to fabricate crown ether (2-methylol-12-crown-4, 2M12C4) immobilized porous polymers (PGMA-CE) was reported toward lithium(I) (Li+) recovery. Macroporous polymer foam (polymeric glycidyl methacrylate, PGMA) with abundant epoxy groups was firstly prepared as a support using a high internal phase emulsion (HIPE) template. And then 2M12C4 was covalently attached onto the surface of PGMA to endow the PGMA-CE with good stability and high selectivity. PGMA-CE was characterized by SEM, FT-IR, XPS, and 13C NMR spectroscopy, and its porous structure and the successful introduction of 2M12C4 were confirmed. In batch mode experiments under optimum conditions, PGMA-CE exhibited fast adsorption kinetics (the equilibrium time was 3.0 h), and the kinetics data were well described using a pseudo-second-order model. A Langmuir-type monolayer adsorption was investigated, and the calculated maximum equilibrium adsorption capacity was 3.15 mg g−1. In addition, PGMA-CE displayed excellent selectivity for Li+ in the presence of multiple interfering ions (Na+, K+, Mg+, and Ca2+), and the selective separation factors (α) were above 4.75. Regeneration analysis showed that the adsorption capacity of PGMA-CE toward Li+ after five cycles was 91.8% of the first cycle.

A metal-organic framework (CuBDC) that possesses cascade cysteine oxidase- and peroxidase-mimicking activities and stimulus-responsive fluorescence was designed by coordinating cupric ions with terephthalic acid. The three-in-one CuBDC provided a new and extremely convenient turn-on fluorescence platform for selective and reliable detection of cysteine.

Highly efficient adsorption of radioactive uranium from seawater is a grand challenge of mounting severity as the energy demand increases. To address this, a salicylaldoxime functionalized raspberry-like microbeads sorbent is created to achieve highly efficient uranium adsorption via the CO2-in-Water Pickering emulsion-assisted polymerization-induced self-assembly method. The prepared raspberry-like microbeads sorbent with a high density of accessible functional groups exhibits the maximum uranium adsorption capacity of 41.02 mg g−1 within 30 min, the time required to reach adsorption equilibrium is shorter than most of the reported amine-oxime functionalized microsphere adsorbents. In addition, under the coexistence of high-concentration metals such as Na+, Mg2+, K+, Ca2+, etc., the raspberry-like microbeads sorbent still showed the best affinity for uranium, which is mainly benefit from the specific binding between amine oxime group and uranium. Our work not only provides a general strategy for the rapid and selective adsorption of uranium from seawater, but also provides a new perspective for the controlled assembly of NSs and the preparation of nano-hybrid materials combining the advantages of micro/nano structures.

Efficient separation of adjacent rare earths is an interesting and challenging job for membrane separation scientists. In this article, a novel polymer inclusion membrane (PIM) incorporating the hydrophilic additive random copolymer poly (vinyl alcohol-co-ethylene) (EVOH) was synthesized. Due to the polarity of P = O and P-OH groups in Cyanex272 and hydrophilicity of –OH groups in EVOH, the membranes exhibited much smaller water contact angles than pure PVDF membranes. And FT-IR results indicated that the addition of EVOH made no difference on the coordination between P = O, P-OH in Cyanex272 and Lu3+. SEM and AFM results indicated that the addition of appropriate amount of EVOH could generate more and larger surface pores and internal channels. Optimum membrane compositions and permeation conditions were fixed via static adsorption and dynamics permeation experiments. Separation factor was calculated as high as 3.78, which was much higher than previous studies no matter in solvent extraction or membrane separation. It is worth noting that it’s the first time an obvious carrier’s leakage was observed via characterizations which implied Cyanex272 may be not a perfect carrier in terms of PIM’s stability. All these results proved that this novel PIM with EVOH serving as hydrophilic additive could be further testified in heavy rare earths separation and purification process.

Affording the ultrahigh structural properties and rich surface groups in traditional activated carbon (AC) together to enable the efficient control of polar volatile organic chemicals (VOCs) is significant but challenged. Herein, we report the skilled construction of super activated carbon (AC) adsorbent (SBET = 4402 m2 g−1) via N-doping tactic to trigger the deep surface digging effect for banana peel-derived AC (SBET = 3897 m2 g−1) and remarkably reinforced the multilayer adsorption behavior by the post-implanted surface N species. Impressively, the resultant optimized adsorbent UC-5 shows nearly 1.83 folds enhancement of polar VOCs(volatile organic chemicals) that acetone adsorption capacity (44.89 mmol g−1) under 30 kPa of acetone partial pressure compared to the original AC (24.57 mmol g−1), which is known as the record acetone adsorption capacity. Besides, the boosting adsorption effect was well inherited and enlarged under a higher saturated vapor pressure of acetone in the static adsorption process, which was further evidenced by dynamic adsorption breakthrough experiments. The intensive studies revealed that the surface digging of the used urea dopant not only contributed to the enriching of surface N and improved the structural properties and thermal stability (575 °C) but also reserved more oxygen content of original AC compared to the resulted counterparts using melamine, which were together responsible for the drastic increase of acetone adsorption. This work provides the new possibility for the adsorption of polar VOCs gas via exploiting the outstanding structural properties and surface N interaction.

In this work, we present a new multi-functional imprinted composite membrane to be used for selective tetracycline (TC) and oil-in-water emulsion separation. In order to improve the hydrophilicity of the PVDF base membrane, delayed phase inversion method was utilized to introduce the hydrophilic UiO-66-NH2, while polydopamine (pDA) coating provides a secondary reaction platform. The imprinted composite membranes were prepared by a simple sol-gel process where TC was used as the template and 3-aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) were the functional monomer and crosslinker, respectively. The PUIM has superhydrophilicity/underwater superoleophobicity with water contact angle (WCA) of 0° and underwater oil contact angle (UOCA) of 162°. The prepared membrane can not only selectively separate TC from surfactant-stabilized emulsion with separation efficiency of 89.1%, but also separate various oil-in-water emulsions with separation efficiency of above 99%. Moreover, the imprinted composite membranes (PUIM) showed excellent antifouling performance, indicating that it could maintain stable separation performance after repeatedly used in separation process. Combining all these results, the multi-functional imprinted composite membranes demonstrate high potential to be employed in wastewater treatment processes, containing organic and oil.

Periodic Mesoporous Organosilica (nano)materials (bulk PMO and PMO NPs), one of the most advanced organic–inorganic hybrid silica materials, are increasingly studied in recent years. Compared with other hybrid silica materials, PMOs have some unique advantages, such as robust porous channels, organic–inorganic framework, tunable pore size arrangement, biocompatibility, high organic contents and easy functionalization. They have attracted growing interest of study in some newly emerged fields including biology, biomedicine and catalysis. On the other hand, heavy metals in wastewaters severely pollute the environment and thus do harm to the aquatic ecosystems as well as human health, which is considered an urgent issue to be solved in modern society. It is very meaningful to use PMO materials to realize the effective detection of heavy metal ions and to solve their recovery. Herein, this review focuses on the synthetic strategies of PMO adsorbents as well as their performance and mechanism of adsorption for the heavy metals.

Simultaneous construction of porous and hollow adsorbent, especially from gas-in-water Pickering emulsion (PE) reactor, is vital for improving mass transfer kinetics and uptake amount. Inspired by the formation process of stalagmites in karst cave, amino and amidoxime bifunctionalized lotus root-type microsphere with porous surface (NH2@AO-PLRMS) is prepared by the silica nanoparticles (SPs)-stabilized CO2-in-water Pickering emulsion reactor and subsequent two-step grafting polymerization. The important roles of SPs acting as Pickering emulsifier, surface pore-forming agent, and adjusting internal lotus root structure are confirmed. Lotus root-type pores are dependent on the interface intensity and the permeability for compressed CO2 bubbles in PE droplets. Benefitting from the lotus root-type structure and abundant affinity sites, the maximum uranium adsorption capacity of NH2@AO-PLRMS is 1214.5 mg·g−1 at 298 k, and an ultrafast uptake process can be achieved in the first 30 min. Both thermodynamic and kinetic studies indicate a spontaneous, entropy increased, and exothermic chemisorption process, and the synergies of amidoxime and amino groups can enhance the adsorption selectivity. Remarkably, NH2@AO-PLRMS displays a high uranium adsorption capacity and desorption efficiency after seven cycles. These findings provide a way to obtain adsorbents with enhanced uranium extraction performance from gas-in-water PE reactor.

The past decade has seen a period for the rapid development of nanozymes. As a class of nanoscale materials with some enzyme-like properties, nanozymes not only possess catalytic activity comparable to that of natural enzymes with the help of advanced technologies, but also have unique superiorities including excellent robustness in harsh environments, large-scale production, low cost, and ease of performance modulation. These advantages make them a promising generation of artificial enzymes for various applications. Especially in the analytical field, the nature of nanozyme catalysis offers amplified signals for high-sensitivity detection. However, most of currently developed nanozymes lack essential catalytic specificity, which becomes one of their biggest challenges in sensing. How to realize selective detection turns to be a vital problem in the nanozyme analytical community. In this review, we first summarize strategies available to make nanozymes work for the analytical application with good specificity. Then, typical examples utilizing these strategies to achieve selective detection are introduced, followed by the discussion of their merits as well as challenges. In the end, trends of nanozymes in this promising area are presented, to provide some guides for designing nanozyme sensing methods and devices for practical applications.

Mixed-matrix membranes with metal-organic frameworks (MOFs)-based dual-imprinted structure (MMM-MDIs) were prepared by choosing tetracycline (TC) as the template molecule. Polydopamine (PDA)-based TC-imprinted UiO-66 particles (PDA-TC-UiO-66) were constructed by developing a self-polymerization imprinting technique of dopamine, in which the dopamine molecule could be regarded as functional monomer and cross-linking agent in the same time. After the phase conversion membrane production, the sol-gel-based TC-imprinted structure could be then synthesized on the membrane surface. Importantly, due to the preparation of the dual-TC-imprinted structure in MMM-MDIs, high adsorption capacity (48.62 mg/g) and fast adsorption equilibrium rate (within 60 min) had been successfully achieved. Meanwhile, excellent permselectivity rates (β) of MMM-MDIs toward TC were also obtained as 6.33, 5.93 and 6.73, which demonstrated the successful synthesis of high-affinity and high-density TC-imprinted sites. Overall, based the practical selective separation and scalability analysis, we believed that the as-prepared MMM-MDIs with high-intensitive recognizability and permeability of template molecule would provide a possibility for breaking the permeability-selectivity trade-off of molecularly imprinted membrane materials.

Monodispersed magnetic sorbents (MMSs) display great potential for adsorptive removal of pollutants, but the conventional methods cannot meet requirements of scalable, time-saving, and energy-efficient fabrication. In this work, space-confined synthesis of nitrilotriacetic acid immobilized magnetic sorbents (NAIMSs-E) in aqueous continuous phase of high internal phase emulsions (HIPEs) was conducted, and as-prepared high quality sorbents (sensitive response to magnetic field, abundant affinity groups, uniform shell size, and stable structure) were applied for removing bivalent cadmium (Cd2+) from aqueous solutions. 2-(Bis-carboxymethyl-amino)-6-{3-[2-(3,4-dihydroxy-phenyl)-ethylcarbamoyl]-propionylamino}-hexanoic acid was firstly synthesized as a robust anchor and a functional modifier onto magnetic Fe3O4. The effects of synthesis conditions to the morphology and structure were studied, and the forming mechanism based on emulsion nano-reactor was demonstrated. NAIMSs-E are expected to possess fast equilibrium rate, and approximately 90% of the maximum adsorption capacity is achieved within 60 min. The maximum uptake amounts are 49.98 mg g−1, 80.58 mg g−1, 176.4 mg g−1 at 288 K, 298 K, and 308 K, respectively, and the monolayer chemisorption based on sharing and transferring of electrons is the main rate-limiting step. Moreover, NAIMSs-E have excellent regeneration and specific affinity towards Cd2+, even for actual water samples. In addition, the spontaneous, endothermic, and entropy increased adsorption process is also confirmed. Therefore, this work not only presents a new clue to fabricate MMSs via simple emulsion nano-reactor, but also provides a novel platform for Cd2+ removal.

In this work, a surface molecular imprinted polymers (MIPs)-based boronate affinity adsorbent was prepared on dendritic fibrous silica particle (DFSP) for rapid recognition and selective separation of shikimic acid for the first time. Double recognition of both imprinted cavity and boronate affinity endowing the MIPs material high adsorption capacity and superior selectivity, which could reach 43.708 mg g−1 at 308 K and pH 8, relatively higher than other reported materials. In addition, pH response adsorption towards SA was achieved in the work. Under the optimum condition, the experimental kinetics data is confirmed to the pseudo-second order model (R2 = 0.9957), and the adsorption process of shikimic acid is well fitted with the Langmuir model (R2 > 0.99). In contrast, the adsorption quantity of MIPs based adsorbent was 3.75 times higher than that of non-imprinted samples. Moreover, the as-obtained MIPs showed comparable reusability after five cycles of continuous adsorption–desorption, which maintained 86.38% of the initial adsorption quantity. The enhanced selectivity property and good regeneration performance makes the boronate affinity MIPs a promising and practical material for rapid recognition and specific capture of shikimic acid. Therefore, the strategy posed in this work sheds new light on the role of boronate affinity MIPs in the adsorption of shikimic acid.

Up to now, extraction of shikimic acid (SA), precursor of antiviral drugs, from the surrounding plants is the most effective and sustainable method. However, it’s still a tough challenge to obtain high purity SA due to the complex components in the plant issue. In this study, based on the specific identification of boronate affinity, iron hydroxide oxide FeOOH with abundant functional groups was used as the substrate to prepare molecular imprinted polymers (FeOOH@MIPs) for selective recognition and adsorption of SA. Using 4-vinylphenylboronic acid (VPBA) as functional monomer, the imprinted polymers were prepared by the controllable directional surface imprinting method. FT-IR analysis and XPS study confirmed the characteristic structure and component of the products. From the results from the batch mode experiments, the maximum adsorption capacity of shikimic acid by FeOOH@MIPs can reach 42.919 mg g−1, which was enhanced compared with nonimprinted products. In addition, the adsorption process was well fitted with Langmuir isotherm model and pseudo-second-order model, implying the chemisorption of SA onto FeOOH@MIPs through the monolayer. The investigation on pH factor showed that the adsorption amount towards SA increased and then declined with the increase of pH value in the surrounding solution, attributing to the feature of boronate affinity effect. More importantly, it was found that the adsorbent exhibited competitive reusability performance. FeOOH@MIPs maintained 86.45% of the first cycle adsorption capacity towards SA after 5 cycles, giving a reasonable proof for the feasible application of the products in the separation of substances containing the special structure of cis-diol.

Detection of pesticide residues is important because it is related to food and environmental safety. Although lots of sensors have been developed and applied for pesticide analysis, most of them rely on the use of vulnerable bioenzymes, weakening the highlights of these sensors. Here we recommend a bioenzyme-free colorimetric assay of malathion, a typical organophosphorus pesticide, based on the analyte inducing the oxidase-mimicking activity loss of Ag3PO4/UiO-66. Compared to counterparts, the Ag3PO4/UiO-66 composite can provide enhanced oxidase-mimetic catalytic activity to trigger the 3,3′-tetramethylbenzidine chromogenic reaction with the participation of dissolved O2. When malathion exists, it rapidly adsorbs onto the composite surface via their unique interactions and significantly shields the oxidase-like activity of Ag3PO4/UiO-66, thus affecting the catalytic chromogenic reaction. With such a principle, sensing of malathion in a wide linear range (0.0083–5.333 μg/mL) was realized with a detection limit 7.5 ng/mL. Given no biological elements were involved in the proposed assay, it exhibited robust and reliable performance in determining malathion in practical samples. Furthermore, a chromogenic hydrogel-based smartphone sensing system was developed for instrument-free on-site analysis of malathion. With good analytical performance and facile operation, our assay and device will find promising applications in phosphothionate pesticide determination.

Efficient recovery lithium ions (Li+) from brine is a recognized challenge with potential strategic and economic implications. In this work, one-step double emulsion reactors, based on amphiphilic Se N supramolecular interactions between phenyl selenium bromide (PhSeBr) and polystyrene-b-polyvinylpyridine (PS-b-P4VP), was constructed to prepare porous multi-cavity beads (PMCB). After immobilizing aminoethyl benzo-12-crown-4 (B12C4-NH2) through post-interface modification strategy, the resultant sorbents (PMCB-B12C4) were adopted for selective separation and enrichment Li+ from brine. PMCB-B12C4 possessed surface pores, multiple interconnected chambers, and abundant crown ether receptors, and the dynamic and adjustable mechanism between structure and turning the volume fraction was also studied. Li+ adsorption in PMCB-B12C4 is best approximated by Langmuir and Hill isotherms showing the homogeneous adsorption on the heterogeneous surface, and the calculated maximum monolayer adsorption capacities are 61.35 mg g−1 and 59.53 mg g−1, respectively. Kinetic study reveals good agreement by pseudo-second order, and chemical adsorption mainly dominates the adsorption process. The mass transfer study depicts that both membrane and inter-particle diffusion are involved in a diffusion inhibition rate process. PMCB-B12C4 can selectively recovery Li+ from simulated samples with the selectivity coefficient (α) and relative selectivity coefficient (αr) as high as >5.0 and 6.0, respectively. PMCB-B12C4 still retains significant Li+ uptake capacity in brine owing to the specific “size matching” effect of crown ether. Moreover, PMCB-B12C4 is regenerated in mild acid and exhibits nearly consistent adsorption capacity after five reuse cycles. Thus, this work not only reports a new clue to fabricate porous sorbent beads via droplet reactor, but also provides a novel platform for Li+ extraction.

The study of aqueous foams has long been an interest of the scientific community. A developing area is the use of foams to prepare lightweight, functional solid foam materials. To design such porous materials, abundant foams should first be generated (good foamability), followed by foam destabilization processes being ceased or significantly retarded (excellent foam stability) to avoid the foam decay upon drying, which can be achieved by finely controlling interfacial behaviour of the foaming agents. The current review considers the interfacial behaviour and foaming potential of emerging nanocomposites such as: surfactant-nanoparticle composites; polymer-nanoparticle composites; and surfactant-graphene oxide (GO) composites. Compared with using only surfactants, polymers or nanoparticles, composite stabilizers are of great interest and importance since they enrich the interfacial behaviour of the bubble-stabilizing film (e.g. mechanical and structural properties), ensuring excellent foamability and long-term foam stability, and novel applications of the solid foam materials. Preparation mechanisms, properties and applications of solid foams prepared via direct foaming methods using the nanocomposite stabilizers are presented and highlighted. For the surfactant-NPs composites, the influences of the property of the foamed suspension and the bubble-stabilizing interface, on the quality of the wet and solid foams, is still elusive. As to the polymer-NPs composites, functional solid foams preparation using their stimuli-responsive performance remains an interesting topic for future research. The fundamental colloidal properties of surfactant-GO composites at the air–water interface and in stabilizing foams remain incompletely understood. Future studies are desired, combining experiments at various scales: interfacial films, Plateau borders, bulk liquid, bubbles, and foams, etc.

Exploring high-performance sensors for toxic arsenic detection is highly desired because of its great threat to the environment. Herein, we report a ratiometric fluorescent biosensor based on acid phosphatase and hemin loaded multifunctional Zn-based metal–organic framework (ACP/hemin@Zn-MOF) for high-performance arsenate (As(Ⅴ)) sensing. ACP/hemin@Zn-MOF is constructed by self-assembly, where hemin exhibits peroxidase-like activity and 2-aminoterephthalic acid ligand endows ACP/hemin@Zn-MOF with an intrinsic fluorescence (452 nm). When ACP/hemin@Zn-MOF catalyzes the oxidation of o-phenylenediamine (OPD), fluorescent 2,3-diaminophenazine (DAP) with an emission signal (564 nm) is produced and weakens ACP/hemin@Zn-MOF intrinsic fluorescence (452 nm) due to inner filter effect; after adding ascorbic acid 2-phosphate (AAP), ACP can hydrolyze AAP and produce ascorbic acid, which competitively suppresses the oxidation of OPD, resulting in the decrease of DAP signal (564 nm) and the recovery of ACP/hemin@Zn-MOF signal (452 nm); when As(V) is added, it irreversibly poisons ACP against hydrolyzing AAP, and the fluorescence signal at 564 nm recovers and the one at 452 nm is suppressed again. High-sensitivity and high-selectivity detection of As(V) (3.33–300 μg L−1) is realized, with a detection limit of 1.05 μg L−1. The biosensor was also successfully employed to detect total arsenic and As(V) in rice.

A dual temperature responsive Cd(II) imprinted polymer (DT-IIP) was newly synthesized by taking merits of surface imprinted technology and photo-initiated controlled/living RAFT polymerization. The preparation, structure, properties as well as the temperature switching controlled behaviors and mechanism of DT-IIP were investigated in detail. SEM, TEM, FT-IR, TGA, XRD and N2 adsorption-desorption were applied to characterization, demonstrating that DT-IIP possesses dual temperature sensitive shells which account for thermo-responsive behaviors. The adsorption performances of DT-IIP towards Cd(II) were assessed by adsorption condition optimizing, the isotherm model, the kinetic model along with selectivity and recognition ability analysis. Moreover, the temperature switching controlled absorption, separation and regeneration of DT-IIP was simply performed, which stems from the two LCST values possessed, so that the distinguished thermo-responsive behaviors can be effectively controlled by single temperature factor. The structure changes of temperature sensitive shells in DT-IIP when exposed above or below LCST value are responsible for the temperature adjusting controlled behaviors. The reusability of DT-IIP was also appraised after temperature controlled adsorption, separation and regeneration sections, proved to be with splendid competence. This is the first time that dual temperature responsive imprinted polymers were effectively adapted to single temperature factor switching control of adsorption, separation and regeneration, which is of great value to sorbent recycling.

Surface-imprinted nanoparticles with double recognition (DM-MIPs) are fabricated onto halloysite nanotubes (HNTs) for highly specific separation of natural flavone luteolin (LTL) under neutral condition. Specifically, a two-step strategy via consecutive surface-initiated atom transfer radical polymerization (SI-ATRP) is employed to introduce inherent recognition of molecular imprinting and reversible covalent affinity of boronic acid ligands and immobilized Zn2+ into DM-MIPs. First, Zn2+-immobilized poly(vinyl imidazole) (PVLD) shell based on the HNTs via the first SI-ATRP is prepared to capture LTL by metal chelating. Then HNTs-supported surface imprinted nanoparticles are prepared using low pKa boronic acid monomer 4-(2-acrylamidoethylcarbamoyl)-3-fluorophenylboronic acid (AMC-FPBA) via the second SI-ATRP. Taking advantage of low apparent pKa of AMC-FPBA and large high-affinity binding site density, DM-MIPs possess a promising binding with cis-diol-containing LTL under neutral condition. In static adsor...

For metal-organic frameworks (MOFs), introduction of special functional groups and integration on porous support will endow the MOF with specific molecular affinity and tunable membrane-like surface properties. Herein, we demonstrated a facile interface-induced Zn(II)-ligand-fragment co-assembly strategy to in situ fabricate boronate-based MOF membrane on hydrophobic porous carbon substrate for specific molecular recognition and separation. Due to the phenylboronic acid groups and hydrophobic porous carbon supporting layer, a catechol-containing medicinal natural flavone Luteolin was found to be efficiently and selectively recognized on the MOF composite in water-containing solution. As compared to the separated MOF particles and carbon substrate, the MOF composite exhibited similar adsorption kinetics but significant higher adsorption capacity in static separation. Dynamic separation also revealed that the MOF composite could achieve a desirable maximum adsorption capacity under mild separation condition, implying its applicability in industrial application. As a proof of this concept, a commercially available Luteolin with 85% purity could be easily extracted and concentrated to 99.90% purity by the MOF composite in highly aqueous solution, and the products possessed the similar antibacterial performance with standard substance. These results demonstrated that, a membrane-like functionalized MOF composite with enhanced surface hydrophobicity and improved molecular specificity has great potential for separation of industrial and even biological samples under water compatible conditions.

A highly fluorescent carbon dots were prepared by a facile one-pot hydrothermal method using degrease cotton (human waste) as the carbon source. The structure and morphology of prepared C-dots were characterized by fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The as-prepared C-dots exhibit excellent emission property, high stability and have a narrow size distribution of 2–4 nm in diameter. Moreover, it is attractive that C-dots can be used as an effective fluorescent probe for the detection of chromium ions with good selectivity and sensitivity in an aqueous solution. The quenching phenomenon was observed after the C-dots interacted with the metal ions; and the results showed that the optimum conditions for its interaction with chromium ions were: 4.0×10−5 g/mL of concentration of C-dots, pH=6.5 of buffer solution, and 20 min of time. Based on the optimum conditions, a new sensitive method detecting chromium ions was established. The method has been successfully applied to detect chromium ions in water and soil samples with satisfactory results.

In this work, a novel route to deconstruct cellulose into 5-hydroxymethylfurfural (HMF) by cascading enzymatic and chemical reactions is reported. For biocatalyst preparation, Fe3O4 nanoparticles encapsulated SBA-15 with appropriate pore size was synthesized and utilized as magnetic scaffolds for the immobilization of cellulase. For chemical catalyst preparation, sulfated zirconium dioxide conformed monolayers were grafted on SBA-15 template to create thermally robust mesoporous catalysts with tunable solid basic/Lewis acid and Bronsted acid sites. Catalytic performance of biocatalyst and chemical catalyst was explored in the aqueous phase conversion of IL pretreated cellulose to glucose, and in the iPrOH/water solvent conversion of glucose to HMF conversion, respectively. After the optimization of reaction conditions, a sequential conversion of pretreated cellulose to glucose and glucose to HMF was performed, and 43.6% HMF yield can be obtained. The cascaded enzymatic and chemocatalytic reaction system demonstrates an effective and economically friendly process for biomass energy conservation. A novel route for green conversion of IL pretreated cellulose to 5-hydroxymethylfurfural (HMF) by cascading an enzymatic catalysis in an aqueous system with chemocatalysis in an iPrOH/water solvent mixture is reported. © 2017 American Institute of Chemical Engineers AIChE J, 2017

An apparent disadvantage of boronate affinity is that it has to be performed in alkaline media and can lead to the oxidation of cis -diols in compounds. A new strategy named as post functionalization with B-N coordination complex was present to prepare boronic acid suspended macroporous polymeric monolith for the selective capture of cis -diol-containing luteolin (LTL) under neutral condition. In this work, a water-in-oil (W/O) Pickering (high internal phase emulsions) HIPE template stabilized by boronic acid suspended mesoporous silica nanoparticles (BA-MSNs) was applied to prepare macroporous poly(glycidyl methacrylate) monolith (PGM-Pickering-0.10), and then B-N coordination complex resulted from the reaction of 3-aminophenylboronic acid (APBA) and 1,6-hexamethylenediamine was integrated to the PGM-Pickering-0.10. As-prepared hierarchical porous PGM-Pickering-0.10-BN with “Wulff-type boronic acids” possessed special mesopore-in-macropore structure. In static adsorption, pH-dependent adsorption experiments demonstrated that PGM-Pickering-0.10-BN was able to capture LTL with expected high adsorption amount (158.5 µmol g −1 at 298 K) and fast binding kinetics (equilibrium in 2.0 h) under neutral condition, while macroporous polymers without post functionalization or functionalized only with APBA display poor adsorption performance at pH = 7.0. In addition, BA-MSNs as the stabilizers enhanced the mechanical property and specific adsorption ability of PGM-Pickering-0.10-BN simultaneously, and the integrated B-N coordination complex did play vital roles in the specific adsorption of LTL. By optimizing dynamic adsorption factors with response surface methodology (RSM), the maximum adsorption amount of 177.8 µmol g −1 was also achieved under neutral condition.

Herein we reported a facile method to prepare porous ion/molecule imprinted polymers (I-MIPs) via twice imprinting strategy for the simultaneous uptake of copper ions (Cu(II)) and λ-cyhalothrin (LC). Firstly, N -(β-aminoethyl)-γ-aminopropytrimethoxysilane (DAMO) was grafted on silica particles surface to synthesis Cu(II)-imprinted polymers to introduce iron imprinted sites. They were then utilized as stabilizers to prepare a stable W/O Pickering HIPEs template (LC as the imprinting molecule), which was then polymerized with dual imprinting sites including Cu(II) and LC. The adsorption equilibrium, kinetic results and selective recognition experiments were exhibited their prospected dual selectivity and simultaneous removal of LC and Cu(II).

Undoubtedly, electrocatalyzing the hydrogen evolution reaction (HER) is now becoming the subject of extensive studies due to its crucial role in harvesting clean energy. In general, bare screen-printed carbon electrodes (SPCEs) have negligible ability to catalyze the HER due to the lack of effective sites. Here we find that: 1) a facile anodization treatment can improve the electrocatalytic activity of home-made SPCEs with apparently reduced overpotential and increased current density for the HER; 2) the activity enhancement of SPCEs is highly dependent on anodization conditions including electrolyte, treatment time, and anodization potential; 3) the introduction of negatively charged oxygen-containing functional groups during anodization, together with the increased defect sites and hydrophilicity on electrode surface, leads to the promoted activity of anodized SPCEs synergistically. Similar phenomena are also found in other carbon-based electrodes including glassy carbon electrode and carbon nanotube-modified electrode. These findings reported in this work are expected to guide the future design of advanced electrode systems for efficient hydrogen evolution.

Different generations of porphyrin-cored dendrimers consisting of novel siloxane- poly(amido amine) dendron-like arms have been synthesized via copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of azide-modified 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin with different generations of propargyl focal point novel siloxane-poly(amido amine) typed dendron (Si-PAMAM). The used different generations of Si-PAMAM were obtained by the “arm-first” strategy based on the Michael addition reaction and Amidation reaction, orderly. The structure of porphyrin dendrimers is established by 1 H NMR, 13 C NMR, MALDI-TOF-MS and FT-IR analysis. PP-Si-PAMAM-Dm (m = 1, 2, and 3), not only gave strong fluorescence emission and the intensity increased significantly as the generation growing, but also showed a remarkable pH-responsive in fluorescence emission. These interesting properties indicate that synthesized porphyrin dendrimers may be able to act as pH-responsive probes suitable for biomedical imaging, diagnosis and treatment.

In this work, a new strategy to construct the acid-base bi-functionalized SBA-15 catalysts was reported. Bilayer zirconia conformal monolayers were first grafted and sulfated on SBA-15 to create 2SZ@SBA-15 catalyst with Bronsted/Lewis acid and base active sites. The obtained 2SZ@SBA-15 sample was further functionalized with acid (–SO 3 H), base (–NH 2 ) and both acid-base (–SO 3 H and –NH 2 ) functional groups (namely, 2SZ@SBA-15-SO 3 H, 2SZ@SBA-15-NH 2 and 2SZ@SBA-15-SO 3 H-NH 2 , respectively). The catalytic activities of the SBA-15 supported catalysts were evaluated toward the cellulose conversion to 5-hydroxymethylfurfural (HMF) in an ILs-based system, which experiences a series of sequential processes involving a decomposition step to glucose, an isomerization reaction to fructose and the fructose triple dehydration step with three molecules of water to HMF. With the goal of understanding the role of catalysts in the sequential processes for cellulose to HMF conversion, the synthesized catalysts possessing different Bronsted/Lewis acidity and basicity were applied in the reactions using cellulose, glucose and fructose as starting materials. Results of catalytic experiments indicated the integration of required acid and base characters in one catalyst has advantageous property for cooperative catalysis of one-pot cellulose to HMF. Highest HMF yield of 42.2% and selectivity of 54.0% can be obtained from cellulose under the optimal conditions. This work represents a continuation of efforts for fabrication and application on multi-functional heterogeneous catalyst for excellent conversion of one-pot cellulose to HMF.

Macroporous polymers with boronate affinity ability (MPs-BA-1) were prepared via high internal phase emulsions (HIPEs) template and then applied to selective adsorption a natural favonoid luteolin (LTL). As-prepared MPs-BA-1 possessed macroporous polymer network and accessible binding sites for cis -diols, and its adsorption behaviors were studied using static and dynamic methods. In static conditions, adsorption amount of LTL increased rapidly in the first 30 min and reached to equilibrium in approximately 2.0 h. Superior conformity of the second-order model confirmed the chemical nature of the interaction between the LTL and binding sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption amounts at 298 K, 308 K and 318 K were 60.97 μmol g −1 , 70.10 μmol g −1 , and 55.03 μmol g −1 , respectively. Dynamic adsorption incorporated with the analysis of response surface methodology (RSM) suggested that the optimal adsorption amount (73.47 μmol g −1 ) achieved when the flow rate of LTL solution was 3.0 mL min −1 , temperature was 28.28 °C and concentration of LTL solution was 30 mg L −1 . MPs-BA-1 served the specific adsorption towards LTL, and the recognition mechanism based on borate affinity was also described. MPs-BA-1 retained the adsorption amounts for successive cycles, but the loss using dynamic method was larger than in the batch method.

We developed a simple phase inversion technique to prepare molecularly imprinted membrane (MIM) at room temperature for membrane selective adsorption and separation of methyl p-hydroxybenzoate (M4HB). The prepared SMIP-MIM was characterized by SEM, FT-IR, TGA. Compared with non-imprinted membrane (NIM1-5) adsorbent, SMIP-MIM1-5 adsorbent with high specific surface area and showed higher binding capacity, faster kinetic and better selectively adsorption capacity for M4HB. The maximum isotherm adsorption capacity for M4HB of SMIP-MIM4 was 3.519mg·g−1, and the experimental data was well fitted to the slips model by multiple analysis. The maximum kinetic adsorption capacity and equilibrium adsorption time for SMIP-MIM4 were 1.335mg·g−1 and 160 min, respectively. The mechanism for dynamic adsorption of M4HB onto SMIP-MIM4 was found to follow pseudo-first-order model and pseudo-second-order model. Additionally, the permeability separation factor of SMIP-MIM4 for M4HB compared to a structural analogues methyl 2-hydroxybenzoate (M2HB) could reach 2.847. The adsorption capacity of SMIP-MIM4 for M4HB and M2HB was 0.549mg·cm−2 and 1.563mg·cm−2, respectively. The adsorption behavior of M4HB through SMIP-MIM4 followed the retarded permeation mechanism.

The discharge of iodine-containing wastewater into environment will lead to the water pollution due to the toxicity and radioactivity of iodine and iodine isotopes. A versatile adsorbent which can effectively adsorb the iodine is in high demanded for this issue. In this work, the hierarchically porous bismuth oxide/layered double hydroxide (Bi 2 O 3 /LDHs) composites were prepared based on biological template techniques, and the as-prepared composites show enhanced iodine adsorption capacity compared with LDHs fibers. The Mg Al LDHs fibers with hierarchical architectures are synthesized by directly growth of nanoscaled LDHs platelets on Al 2 O 3 fiber surfaces. The Bi 2 O 3 /LDHs composites with sponge-like structures are prepared by desorption of Bi 2 O 3 on the surfaces of LDHs fibers. The iodine adsorption behavior on Bi 2 O 3 /LDHs composites was examined in sodium iodine aqueous solutions. The appropriate iodine adsorption was obtained at a neutral pH with maximum adsorption capacity of 101.9 mg/g. The Langmuir model successfully describes the iodine adsorption isotherms, while the pseudo-second-order kinetic model is better at describing the iodine adsorption kinetics onto the Bi 2 O 3 /LDHs composites. Since the Bi 2 O 3 /LDHs composites show near complete removal of iodine ions, the as-prepared Bi 2 O 3 /LDHs composites are expected to have practical applications as iodine adsorbent in wastewater treatment.

In this work, small palladium nanoparticles (Pd NPs) inside sulfur-doped carbon microsphere (S-CMS) were synthesized to achieve both high electro-catalytic activity and long durability for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). The highly dispersed Pd NPs encapsulated in S-CMS with an architectural feature like the plum pudding model were obtained via a facile one-pot hydrothermal synthesis employing reduced glutathione (r-GSH) as both reducing and capping agents, followed by a simple carbonization procedure. The synthesized Pd NPs inside S-CMS was found to provide larger effective surface for MOR compared to commercial Pd/C. Mass activity 5.9 times higher than that of Pd/C was acquired, originating from the small size of Pd NPs and their interactions with the heteroatom-modified CMS coating. Due to the decreased agglomeration and dissolution, the proposed encapsulated Pd NPs also kept more stable during continuous start-stop operation, suggesting its great potential as an effective anode material to be used in DMFCs.

The severe environmental and ecological problems, derived from oil spills and organic solvents leakage, have occurred in many parts of the world. It is urgent to seek appropriate ways to resolve oily wastewater and organic solvent pollution. A versatile oil-absorbing material which can separate the oily wastewater effectively and quickly is in high demanded for this issue. In this work, we report a facile and inexpensive to fabricate an effective and recyclable oil-absorbent, namely MnO2 nanowires/polyurethane (PU) foam composites, using a PU sponge as a porous substrate and MnO2 nanowires as modifiers. The hydrothermal method is employed to synthesize MnO2 nanowires and then foaming technology is used to fabricate MnO2 nanowires/PU foam composites. In order to enhance the hydrophobic and oleophilic properties, the surfaces of MnO2 nanowires are chemically modified using silane coupling agent (KH 570). The present MnO2 nanowires/PU foam composites not only effectively separate oils from water as expected, but also possess a very high absorption capacity for the removal of organic solvents from water up to 40.15 times its own weight. More importantly, the obtained MnO2 nanowires/PU foam composites is demonstrated to have excellent oil recoverability and absorbent regenerability, making them versatile and comprehensive absorbents to satisfy various practical oily wastewater and organic solvent separation requirements.