Elucidation of Geniposide and Crocin Accumulation and Their Biosysnthsis-Related Key Enzymes during Gardenia jasminoides Fruit Growth.

Gardenia jasminoides fruits are extensively grown worldwide, with a large harvest, and its major medicinal ingredients are geniposide and crocins. Research on their accumulation and biosynthsis-related enzymes is rare. In this study, the accumulation of geniposide and crocin of G. jasminoides fruits at different developmental stages were clarified by HPLC. The highest cumulative amount of geniposide was 2.035% during the unripe-fruit period, and the highest content of crocin was 1.098% during the mature-fruit period. Furthermore, transcriptome sequencing was performed. A total of 50 unigenes encoding 4 key enzymes related in geniposide biosynthsis pathways were screened, and 41 unigenes encoding 7 key enzymes in the pathways of crocin were elucidated. It was found that the expression levels of differentially expressed genes of DN67890_c0_g1_i2-encoding GGPS, which is highly related to geniposide biosynthesis, and DN81253_c0_g1_i1-encoding lcyB, DN79477_c0_g1_i2-encoding lcyE, and DN84975_c1_g7_i11-encoding CCD, which are highly related to crocin biosynthesis, were consistent with the accumulation of geniposide and crocin content, respectively. The qRT-PCR results showed that the trends of relative expression were consistent with transcribed genes. This study provides insights for understanding the geniposide and crocin accumulation and biosynthsis during fruit development in G. jasminoides.

Superhydrophilic Modification of Polyvinylidene Fluoride Membrane via a Highly Compatible Covalent Organic Framework-COOH/Dopamine-Integrated Hierarchical Assembly Strategy for Oil-Water Separation.

The integration of membranes with additives such as functionalized nanomaterials can be recognized as an effective method to enhance membrane performance. However, to obtain an efficient nanoparticle-decorated membrane, the compatibility of nanomaterials remains a challenge. Hydrophilic carboxylated covalent organic frameworks (COF-COOH) might be expected to avoid the drawbacks of aggregation and easy shedding of inorganic materials caused by the poor interfacial compatibility. Herein, a highly compatible dip-coating strategy was proposed for the superhydrophilic modification of polyvinylidene fluoride membrane via COF-COOH integrated with dopamine. COF-COOH together with polydopamine nanoparticles were uniformly and stably attached to the membrane due to the high interfacial compatibility, constructing a coating with rough hierarchical nanostructures and abundant carboxyl groups. The synergistic effects of multiscale structures and chemical groups endow the membrane with superhydrophilicity and underwater superoleophobicity, the water contact angle decreased from 123 to 15°, and the underwater oil contact angle increased from 132 to 162°. Accordingly, the modified membrane exhibits an ultrahigh oil rejection ratio (>98%), a high flux (the maximum reaches 1843.48 L m-2 h-1 bar-1), attractive antifouling ability, and impregnable stability. This work would provide a momentous reference for the application of COF-COOH in practical oily wastewater treatment.

In-situ constructed 2D/2D ZnIn2S4/Bi4Ti3O12 S-scheme heterojunction for degradation of tetracycline: Performance and mechanism insights.

Semiconductor materials dominated photocatalytic technology is one of the most efficient approaches to degrade organic pollutants. However, the limited light absorption range and rapid recombination of photogenerated carriers greatly restrict the application of photocatalysts. Rational design of photocatalysts to achieve high catalytic activity and stability is of great importance. Herein, ZnIn2S4/Bi4Ti3O12 S-scheme heterojunction is synthesized by growing the ZnIn2S4 nanosheets on the sheet-like Bi4Ti3O12 surface via a low-temperature solvothermal method. The TC removal efficiency of optimized heterojunction reaches 82.1% within 60 min under visible light, and the rate constant is nearly 6.8 times than that of pristine ZnIn2S4. The favorable photocatalytic performance of heterojunction is attributed to the tight contact interface and efficient separation of photogenerated carriers. Besides, the difference in work function between ZnIn2S4 and Bi4Ti3O12 leads to band bending and the establishment of built-in electric field on the contact interface of heterojunction, which facilitates the migration and separation of photogenerated carriers. Furthermore, the cycling test demonstrates the attractive stability of heterojunction. The possible TC photodegradation pathways and toxicity assessment of the intermediates are also analyzed. In conclusion, this work provides an effective strategy to prepare S-scheme heterojunction photocatalysts with favorable photocatalytic activity, which can enhance wastewater purification efficiency.

Hierarchically Nanostructured Solid-State Electrolyte for Flexible Rechargeable Zinc-Air Batteries.

The construction of safe and environmentally-benign solid-state electrolytes (SSEs) with intrinsic hydroxide ion-conduction for flexible zinc-air batteries is highly desirable yet extremely challenging. Herein, hierarchically nanostructured CCNF-PDIL SSEs with reinforced concrete architecture are constructed by nanoconfined polymerization of dual-cation ionic liquid (PDIL, concrete) within a robust three-dimensional porous cationic cellulose nanofiber matrix (CCNF, reinforcing steel), where plenty of penetrating ion-conductive channels are formed and undergo dynamic self-rearrangement under different hydrated levels. The CCNF-PDIL SSEs synchronously exhibit good flexibility, mechanical robustness, superhigh ion conductivity of 286.5 mS cm-1 , and decent water uptake. The resultant flexible solid-state zinc-air batteries deliver a high-power density of 135 mW cm-2 , a specific capacity of 775 mAh g-1 and an ultralong cycling stability with continuous operation of 240 hours for 720 cycles, far outperforming those of the state-of-the-art solid-state batteries. The marriage of biomaterials with the diversity of ionic liquids creates enormous opportunities to construct advanced SSEs for solid-state batteries.

Porous ZrO2 encapsulated perovskite composite oxide for organic pollutants removal: Enhanced catalytic efficiency and suppressed metal leaching.

Cobalt-based perovskite material, an effective activator of PMS, is widely employed for wastewater remediation, but still affected by the leakage of the cobalt ions. In this study, a porous core-shell structured perovskite LaFe0.1Co0.9O3-λ/SiO2 core @ZrO2 shell (LFCS@ZrO2) was fabricated and partially etched to enlarge channels to further enhance mass transfer ability. The well-designed core-shell structure can not only restrain metal ion leaching by changing the surface microenvironment but also provide an additional driving force attributed to the enriched concentration gradient, thus enhancing the catalytic oxidation performance. Results showed that the partially etched LFCS@ZrO2 (eLFCS@ZrO2) particles exhibited an increased pore size and showed an attractive catalytic performance as well as a suppressed cobalt ion leaching (3.61 to 0.67 mg/L). Over 99% of tetracycline hydrochloride (20 mg/L) could be degraded in 15 min, and the reaction rate increased 2 folds compared with pristine LaFe0.1Co0.9O3-λ. Besides, quenching test and electron paramagnetic resonance analysis proved that sulfate radicals and singlet oxygen were the two predominant reactive oxygen species during the catalytic oxidation. This work provides a novel perspective for the fabrication of an environmentally friendly perovskite catalyst, which has a great potential application in organic pollutant degradation.

Study of Turbulence Promoters in Prolonging Membrane Life.

Nanofiltration membrane technology is an effective method for secondary treated sewage purification. However, membrane fouling, which is inevitable in the membrane-separation process, can reduce membrane performance and shorten membrane life. Installing a turbulence promoter is a promising means of improving the hydraulic conditions inside the membrane chamber. In this study, the effect of turbulence promoter on prolonging membrane life was studied for the first time. Flat-sheet polyethersulfone nanofiltration membrane was used to filter humic acid solution, used for simulating secondary treated sewage. By comparing photographs and SEM images of the membrane before and after the simulated secondary treated sewage filtration, it was found that humic acid tended to be deposited on the low-velocity region, which was reflected by COMSOL simulation. After incorporating a turbulence promoter, the reduction of the humic acid deposition area and membrane fouling resistance indicated that the turbulence promoter could reduce membrane fouling due to the improved hydraulic conditions. Additionally, the turbulence promoter also increased the flux and reduced the flux decay rate. The turbulence promoter was then place in the crossflow flat-sheet membrane filtration module, and the variation of flux with time was tested in simulated secondary treated sewage with different concentrations. The results showed that the membrane life for the filtration of simulated secondary treated sewage comprising 50, 250, and 500 ppm humic acid increased by 23.1%, 80.4%, and 85.7%, respectively. The results of this article can serve as a reference for the prediction of membrane life and the performance enhancement mechanism of membranes containing a turbulence promoter.

Microporous framework membranes for precise molecule/ion separations.

Microporous framework membranes such as metal-organic framework (MOF) membranes and covalent organic framework (COF) membranes are constructed by the controlled growth of small building blocks with large porosity and permanent well-defined micropore structures, which can overcome the ubiquitous tradeoff between membrane permeability and selectivity; they hold great promise for the enormous challenging separations in energy and environment fields. Therefore, microporous framework membranes are endowed with great expectations as next-generation membranes, and have evolved into a booming research field. Numerous novel membrane materials, versatile manipulation strategies of membrane structures, and fascinating applications have erupted in the last five years. First, this review summarizes and categorizes the microporous framework membranes with pore sizes lower than 2 nm based on their chemistry: inorganic microporous framework membranes, organic-inorganic microporous framework membranes, and organic microporous framework membranes, where the chemistry, fabrications, and differences among these membranes have been highlighted. Special attention is paid to the membrane structures and their corresponding modifications, including pore architecture, intercrystalline grain boundary, as well as their diverse control strategies. Then, the separation mechanisms of membranes are covered, such as diffusion-selectivity separation, adsorption-selectivity separation, and synergetic adsorption-diffusion-selectivity separation. Meanwhile, intricate membrane design to realize synergistic separation and some emerging mechanisms are highlighted. Finally, the applications of microporous framework membranes for precise gas separation, liquid molecule separation, and ion sieving are summarized. The remaining challenges and future perspectives in this field are discussed. This timely review may provide genuine guidance on the manipulation of membrane structures and inspire creative designs of novel membranes, promoting the sustainable development and steadily increasing prosperity of this field.

Non-precious molybdenum nanospheres as a novel cocatalyst for full-spectrum-driven photocatalytic CO2 reforming to CH4.

Photocatalytic CO2 reforming is considered to be an effective method for clean, low-cost, and environmentally friendly reduction and conversion of CO2 into hydrocarbon fuels by utilizing solar energy. However, the low separation efficiency of charge carriers and deficient reactive sites have severely hampered the efficiency of the photocatalytic CO2 reforming process. Therefore, cocatalysts are usually loaded onto the surface of semiconductor photocatalysts to reduce the recombination of charge carriers and accelerate the rates of surface reactions. Herein, molybdenum (Mo) nanospheres are proposed as a novel non-precious cocatalyst to enhance the photocatalytic CO2 reforming of g-C3N4 significantly. The Mo nanospheres boost the adsorption of CO2 and activate the surface CO2via a photothermal effect. The time-resolved fluorescence decay spectra reveals that the lifetime of photo-induced charge carriers is prolonged by the Mo nanospheres, which guarantees the migration of charge carriers from g-C3N4 to Mo nanospheres. Unexpectedly, Mo loaded g-C3N4 can effectively utilize a wide spectral range from UV to near-infrared region (NIR, up to 800 nm). These findings highlight the potential of Mo nanospheres as a novel cocatalyst for photocatalytic CO2 reforming to CH4.

Boron Nitride Membranes with a Distinct Nanoconfinement Effect for Efficient Ethylene/Ethane Separation.

A BN membrane with a distinct nanoconfinement effect toward efficient ethylene/ethane separation is presented. The horizontal and inclined self-assembly of 2D BN nanosheets endow the BN membrane with abundant percolating nanochannels, and these nanochannels are further decorated by reactive ionic liquids (RILs) to tailor their sizes as well as to achieve nanoconfinement effect. The noncovalent interactions between RIL and BN nanosheets favor the ordered alignment of the cations and anions of RIL within BN nanochannels, which contributes to a fast and selective ethylene transport. The resultant membranes exhibit an unprecedented separation performance with superhigh C2 H4 permeance of 138 GPU and C2 H4 /C2 H6 selectivity of 128 as well as remarkably improved long-term stability for 180 h, outperforming reported state-of-the-art membranes.

Novel Protic Ionic Liquid Composite Membranes with Fast and Selective Gas Transport Nanochannels for Ethylene/Ethane Separation.

Protic ionic liquids (PILs) were utilized for the fabrication of composite membranes containing silver salt as the C2H4 transport carrier to perform C2H4/C2H6 separation for the first time. The intrinsic nanostructures of PILs were adopted to construct fast and selective C2H4 transport nanochannels. The investigation of structure-performance relationships of composite membranes suggested that transport nanochannels (polar domains of PILs) could be tuned by the sizes of cations, which greatly manipulated activity of the carrier and determined the separation performances of membranes. The role of different carriers in the facilitated transport was studied, which revealed that the PILs were good solvents for dissolution and activation of the carrier due to their hydrogen bond networks and waterlike properties. The operating conditions of separation process were investigated systemically and optimized, confirming C2H4/C2H6 selectivity was enhanced with the increase of silver salt concentration, the flow rate of sweep gas, and the feed ratio of C2H4 to C2H6, as well as the decrease of the transmembrane pressure and operating temperature. Furthermore, the composite membranes exhibited long-term stability and obtained very competitive separation performances compared with other results. In summary, PIL composite membranes, which possess good long-term stability, high C2H4/C2H6 selectivity, and excellent C2H4 permeability, may have a good perspective in industrial C2H4/C2H6 separation.

Improving the Visible-Light Photocatalytic Activity of Graphitic Carbon Nitride by Carbon Black Doping.

Hydrogen production by water splitting and the removal of aqueous dyes by using a catalyst and solar energy are an ideal future energy source and useful for environmental protection. Graphitic carbon nitride can be used as the photocatalyst with visible light irradiation. However, it typically suffers from the high recombination of carriers and low electrical conductivity. Here, we have developed a facile mix-thermal strategy to prepare carbon black-modified graphitic carbon nitrides, which possess high electrical conductivity, a wide adsorption range of visible light, and a low recombination rate of carriers. With the help of carbon black, highly crystallized graphitic carbon nitrides with built-in triazine and heptazine heterojunctions are obtained. Improved photocatalytic activities have been achieved in carbon black-modified graphitic carbon nitride. The dye removal rate can be three times faster than that of pristine graphitic carbon nitride and the photocatalytic H2 generation is 234 µmol h-1 g-1 under visible light irradiation.

Thermo-responsive gels based on supramolecular assembly of an amidoamine and citric acid.

In this work, we report the formation of a novel, aqueous-based thermo-responsive, supramolecular gelling system prepared by a convenient and efficient self-assembly of a long-chain amino-amide and citric acid. To determine the viscosity behavior and to gain insights into the gelation mechanism, a complementary combination of techniques, including Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic light scattering (DLS), and sinusoidal oscillatory tests, were used. The supramolecular gelator exhibited remarkably reversible sol-gel transitions induced by temperature at 76 °C. At a concentration of 5 wt%, the zero-frequency viscosity of the supramolecular system increased by about four orders of magnitude (from 4.2 to 12 563 Pa s) by changing the temperature from 23 °C to 76 °C. The viscous nature of the supramolecular gel could be preserved up to 90 °C. The synergistic combination of the hydrogen bonding between amino and carboxylic acid groups and the electrostatic interactions arising from the protonation of the amino-group and the deprotonation of carboxylic acid groups enhanced at higher temperatures is presumably responsible for the thermo-responsive behavior. We anticipate that these supramolecular gelators can be beneficial in various applications such as hydrogel scaffolds for regenerative medicine, personal care products and cosmetics, and enhanced oil recovery as viscosity modifiers.

Heterogeneous oxidative desulfurization of diesel fuel catalyzed by mesoporous polyoxometallate-based polymeric hybrid.

In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N,​N-​dimethyl-​dodecyl-​(4-​vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species. The catalyst with H2W12O4210- as counterion, which exhibited the best activity in the oxidation of benzothiophene (BT) and dibenzothiophene (DBT) to sulfones in model oil with hydrogen peroxide (H2O2, 30wt%) as oxidant, was characterized by different techniques and systematically studied for its sulfur removal performance. As for the oxidative desulfurization of a real diesel, it was observed that almost all of the original sulfur compounds could be completely converted, and the catalyst could be reused for at least eight cycles without noticeable changes in both catalytic activity and chemical structure. In the end, a catalytic mechanism was put forward with the assistant of Raman analysis.

Uptake and degradation of Orange II by zinc aluminum layered double oxides.

In this work ZnAl-layered double oxide composites (LDO) were developed to remove organic dyes in wastewater by adsorption and photocatalysis. Various LDO composites were synthesized by adjusting synthetic parameters including the molar ratio of Zn to Al, and calcination temperature. LDO adsorption and photocatalytic properties for decomposition of organic dyes were also investigated. Orange II sodium salt (OrgII), an azo dye and water contaminant, was chosen as the model to investigate the properties of LDOs compared with commercial ZnO, TiO2 (P25) and ZnO-LDH. The adsorption and photocatalytic performance results showed that LDO composites significantly enhanced adsorption-photocatalytic performance for OrgII degradation. LDO at the Zn/Al molar ratio of 2 (2)LDO has the best adsorption capacity (800.8 mg/g of OrgII for (2)LDO), and improved photocatalytic activity (74.3% of OrgII decomposition for (2)LDO). It is believed that the better adsorption properties of LDO are due to the adsorption and intercalation of dyes in the interlayer during LDO's rehydration process. ZnO/ZnAl-rehydrated layered double hydroxide composites (ZnO-rLDH) after rehydration of LDOs in aqueous solution was also obtained. After restoration in water, the structure and morphology of ZnO-rLDHs were characterized by XRD, FTIR, SEM/TEM, N2 adsorption/desorption and UV-vis-DRS. Finally, the relations between the structural features of the ZnO-rLDH composites and the adsorption properties and photocatalytic activity of LDO was studied.

ZnO-Layered Double Hydroxide@Graphitic Carbon Nitride Composite for Consecutive Adsorption and Photodegradation of Dyes under UV and Visible Lights.

In this work, a ZnO-layered double hydroxide@graphitic carbon nitride composite (ZnO-LDH@C3N4) was synthesized via co-precipitation method with solvothermal treatment. The structure and morphology of ZnO-LDH@C3N4 composite were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopes/transmission electron microscopes (SEM/TEM), N2 adsorption/desorption, ultraviolet visible diffuse reflectance spectroscopy (UV-Vis-DRS), photoluminescence spectrometer (PL) and electrochemical impedance spectroscopy (EIS). The adsorption and photocatalytic properties of ZnO-LDH@C3N4 composite towards the organic dyes: Orange II sodium salt (OrgII, an anionic azo dye) and methylene blue (MB, a cationic azo dye) were investigated. Compared to ZnO-LDH and g-C3N4, the ZnO-LDH@C3N4 composite displayed an excellent performance in both adsorption and photocatalytic degradation of the organic dyes. Moreover, a combination of ZnO-LDH and g-C3N4 significantly improved the photocatalytic performance of ZnO-LDH and g-C3N4 under visible-light irradiation. The adsorption and photocatalytic mechanism were also investigated.

One-step synthesis of metal@titania core-shell materials for visible-light photocatalysis and catalytic reduction reaction.

Metal@TiO2 composites with a core-shell structure possess multifunctional properties. The demonstrated protocols for synthesizing such materials involve multiple steps, requiring precise control over the particle uniformity of the core and shell thickness, as well as complex surface modification. A simple approach to synthesizing metal@TiO2 hybrid nanostructures remains a great challenge. Herein, we report on a one-step method for the preparation of metal@TiO2 core-shell nanospheres, which exhibited excellent performance in photocatalytic degradation of recalcitrant organic pollutants under visible light irradiation, and in catalytic reduction of nitrophenol in water. The simple method described here represents a sustainable approach to preparing core-shell materials at low cost, involving fewer chemicals, and requiring less energy, which will make a significant contribution toward large-scale synthesis of high-performance hybrid materials for photocatalytic applications.

Synergistic effects of non-thermal plasma-assisted catalyst and ultrasound on toluene removal.

A wire-mesh catalyst coated by La0.8Sr0.2MnO3 was combined with a dielectric barrier discharge (DBD) reactor for toluene removal at atmospheric pressure. It was found that toluene removal efficiency and carbon dioxide selectivity were enhanced in the catalytic packed-bed reactor. In addition, ozone and nitrogen monoxide from the gas effluent byproducts decreased. This is the first time that ultrasound combined with plasma has been used for toluene removal. A synergistic effect on toluene removal was observed in the plasma-assisted ultrasound system. At the same time, the system increased toluene conversion and reduced ozone emission.