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Carbon nitride, considered to be a promising photocatalyst, still has much room to increase the catalytic performance owing to the slow charge transfer and limited light harvesting ability. Herein, carbon doping carbon nitride with hollow tubular structure was successfully developed by using melamine and sodium alginate as precursors via a simple hydrothermal calcination method. The effects of carbon content on the structure and photocatalytic activities of as-obtained carbon nitride were researched in detail. The hollow tubular structure can assist the enhancement of specific surface area, increase of visible light harvesting ability and enhancement of electron transport ability. Simultaneously, carbon doping can adjust the photoelectric performance and band structure of carbon nitride due to the generation of delocalized big π bonds to enhance the photocatalytic activities. The catalytic performance of as-obtained carbon nitride is estimated by hydrogen evolution reaction. And carbon doping carbon nitride with hollow tubular structure accounts for 3 times and 2 times promotion than pristine CN in hydrogen evolution rate under λ > 420 nm and λ > 400 nm, respectively. Especially, the sample CN-40 shows a highly enhanced hydrogen generation efficiency of 1210.3 μmol h-1 g-1, which should be inseparable from the function of carbon doping and hollow tubular structure.

The gut microbiota is widely considered to be involved in several diseases, including atherosclerosis, obesity, chronic obstructive pulmonary disease (COPD) and pulmonary arterial hypertension (PAH). This study aimed to determine if changes in the gut microbiome and metabolome play a major role in the early pathogenesis of PAH. Male Wistar rats were injected with monocrotaline (MCT) (55 mg/kg) at day 1 and injected with calcium-sensing receptor (CaSR) antagonist NPS2143 (4.5 mg/kg/d) from days 1 to 21. Fecal samples were obtained. The gut microbiota and metabolome were analyzed by 16S rRNA gene sequencing and mass spectrometry-based analysis to investigate the effect of PAH in this rat model. MCT injection had a marked effect on the composition of the gut microbiota. This finding was further confirmed by metabolomic analysis with identification of several metabolites relevant to the gut microflora. However, NPS2143 partially abrogated this intestinal flora disorder and reversed fecal metabolite abnormalities. In conclusion, our study shows correlations between changes in the gut microbiome and the metabolome in PAH, which are affected by NPS2143., Graphical abstract

Modifying the texture of carbon nitride to adjust its physicochemical performance is a fascinating method for achieving high photocatalytic activity. Herein, we synthesized 3D porous carbon nitride with ultra-thin nanosheets by using cyanuric acid-melamine supramolecular and ionic liquid as precursor and template, respectively. The ionic liquid adjusts the morphology of materials and induces the carbon residue into the porous channels owing to its incomplete degradation. The 3D porous framework makes carbon nitride reflect the enhanced surface area, exposes adequate reaction sites, and offers a pathway for charge transport. And carbon residue and ultra-thin nanosheets further promote the photogenerated carriers transport and reduce the recombination rate of charge carriers. Consequently, 3D porous carbon nitride with ultra-thin nanosheets exhibit outstanding and stable hydrogen evolution under visible light irradiation. Significantly, as-fabricated sample CN-100 reflects an improved H2 generation rate, up to 17,028 μmol h−1 g−1, which is 12 times higher than that of CN (1412 μmol h−1 g−1). The present work offers a unique synthesis strategy to develop the novel photocatalyst with efficient photocatalytic performance.

Photocatalytic hydrogen evolution reaction (HER) provides a new way for the development of clean energy. Herein, a high-performance peony-like 3D structure S-doped carbon nitride (SCNx) with a large specific surface area was synthesized through a universal and non-thermal polymerization template-free approach. As an additional component, the introduction of trithiocyanuric acid in the raw material led to the formation of supramolecular intermediates through hydrogen bond self-assembly, and the sulfur was introduced into the framework of g-C3N4 subsequently. The charge separation lifetime of SCNx was studied by transient absorption spectroscopy, and the reason for its excellent optical performance was revealed from a dynamic perspective. Furthermore, the resulting SCNx composite material shows significant photocatalytic hydrogen release performance under visible light irradiation. In particular, the photocatalytic hydrogen rate of SCN1.0 reached 567.7 μmol/h, which was almost 53 times that of BCN, and was also 2.3 times that of SCN0 obtained by the binary self-assembly of melamine and cyanuric acid. Our finding advances the application of simple, environmentally friendly, and scalable strategy for the synthesis of high-performance sulfur-doped g-C3N4 photocatalysts.

A hydrophilic terpolymer scale inhibitor (AA–APES–HPAY) was prepared by free radical polymerization with acrylic acid (AA), hydroxypropyl acrylate modified by 2-phosphonobutane-1,2,4-tricarboxylic ...

Carbon nitride is found to be an outstanding metal-free photocatalyst for photocatalytic hydrogen evolution. However, carbon nitride suffers from insufficient light absorption and wide band gap, wh...

Porous cellulose films have been reported as sustainable and highly-efficient non-power radiative cooling (PRC) materials but are still challenged by their insufficient atmospheric window (AM) emissivity and complex preparation technology. Herein, bio-mimetic skin structure inspired 3D porous cellulose acetate hybrid hollow AlPO4 (3D PCA/h-AlPO4) nano-laminated PRC film is creatively fabricated by a proposed solvent polarity matching strategy. Owing to the ultra-rapid extraction of high-quality solvent NMP by water relying on their stronger matching polarity, the PRC film self-forms ultra-rapidly within 5 min and is composed of skin-like wrinkle surface, porous matrix, and dense nanolayer. The wrinkle surface and dense h-AlPO4 nanolayer has been demonstrated to have higher atmospheric window emissivity (∼94.7% and 96.6%) than the smooth surface (88.7%). The self-formed uniform cavities of about 2 μm can contribute to a high solar reflectivity (∼97%). As proof of concept, the bio-structural film is used for all-day cooling under different atmospheric radiations, and about 13.5 °C/5 °C (daytime high solar irradiance of 988 W m−2) and ∼1.5 °C/0.5 °C (nighttime) temperature reduction is realized at low/high (12 °C/35 °C) environment temperatures, respectively. We believe the bio-structure design and ultra-rapid film-formation strategy would inspire the development of polymer-based PRC materials for the highly-efficient energy saving applications.

In this study, we synthesized a series of Ni-based catalysts with different CeO2 contents (0, 1, 2, 5 and 10 wt%) anchoring on the Al-Mg oxide spheres (AMO) with three-dimensional hollow flower-like structure. The triethoxyoctylsilane (TEOOS) and polyvinylpyrrolidone (PVP) were selected as effective modified reagents to introduce hydrophobic functionality on the surface of AMO and Ni-CeO2 nanoparticles, respectively, for controllable anchoring Ni-CeO2 nanoparticles on AMO by hydrophobic interaction driving mechanism. The effects of CeO2 content on the texture, dispersion of Ni species, the reducibility of Ni2+, surface electronic states and acidity were investigated in detail. The Ni-5CeO2/AMO was found to achieve the highest 2,2′-bipyridine selectivity of 90.6% and maximum turnover number (TON) of 8611, specifically. Moreover, the Ni-5CeO2/AMO exhibits superior stability, maintaining 89% of 2,2′-bipyridine yield after 6 runs, due to the mitigated nickel leaching and promotion of the desorption of 2,2′-bipyridine. Furthermore, with the help of DFT calculations, a possible reaction mechanism was discussed and illustrated.

It is essential to manufacture microwave absorbers with strong absorption as well as tunable absorption bands at a low filler content. However, it remains challenging for pure biomass material to reach this goal without loading other components. MoSe2, as a transition metal chalcogenide with semiconductor properties, has emerged as a potential microwave absorber filler. Herein, bacterial cellulose (BC)-derived carbon nanofibers/MoSe2 nanocomposite was fabricated and phosphoric acid was used to dope phosphorus in BC, in which MoSe2 microspheres were dropped on the BC network like a dew-covered spider web. This unique network structure enhances conductive loss and multiple reflections of the incident wave. The collocation of BC and MoSe2 is helpful to impedance match and introduces interfacial/dipolar polarization loss; moreover, the P-doping of BC helps to tune the absorption bands. Overall, the optimal reflection loss of undoped one reaches −53.33 dB with only 20 wt.% filler content, whose main absorption peaks focus on X-band. Interestingly, after the P-doping of BC, the main absorption peaks move to Ku-band and the optimal reflection loss gets stronger (−66.84 dB) with the same filler loading. Strong absorption and tunable absorption bands can be realized, and thus wide frequency range is covered. This work is expected to enlighten future exploration of biomass carbon materials on high-performance microwave absorption materials.

This article has presented a physics-based model which replicates the failure of SiC MOSFET under short-circuit (SC) case. The model is constructed on the base of the traditional circuit model of SiC MOSFET by introducing two leakage current mechanisms; one is the leakage current between the drain and the source, and another is the gate leakage current. Furthermore, the carrier mobility characterized with trapped charges at the interface of SiC/SiO2 is adopted. The failure model had been validated against the experimental results. With the developed failure model, the failure mechanism of SiC MOSFET under a SC event is analyzed; the impact of interface trapped charges on the SC performances of SiC MOSFET is exploited. Moreover, the SC failure for SiC MOSFET with different OFF-state gate voltages has been addressed; the behavior of interface trapped charges has been analyzed.

Fe-doped mesoporous alumina (MA) was successfully synthesized via a facile one-pot synthesis method. The resulting Fe-doped MA samples possess typical mesoporous structure, relatively high BET surface area, and narrowed pore size diameter. Besides, the iron species are well-dispersed in the alumina matrix, and more importantly, some small oligonuclear iron oxide clusters are linked on the surface of alumina, leading to the elimination of strong acid sites. The reaction of phenol hydroxylation was preceded at room temperature for 2 h. The introduction of mesoporous structure in alumina would be favorable for the adsorption and diffusion process of reactant and product molecules, and also the well-dispersed iron species in alumina matrix and large amount of acid sites stimulate more active hydroxyl radicals which are greatly beneficial for the catalytic process, especially the elimination of strong acid sites would inhibit the over-oxidation reaction. In this case, the sample of 5Fe–MA displays the best catalytic performance especially with the extremely high dihydroxybenzene selectivity of 93.2%, and the good catalytic stability is also evidenced by the five times recycling tests. In this work, the Fe-doped mesoporous alumina (MA) was successfully prepared. The iron species are well-dispersed in the alumina matrix, and some small oligonuclear iron oxide clusters are linked on the surface of alumina, leading to the elimination of strong acid sites. The advanced properties of mesoporous structure, well-dispersed metal active centers and lack of strong acid sites in Fe-doped MA are greatly beneficial for the catalytic process, especially for the dihydroxybenzene selectivity with extremely high value of 93.2%.

New catalysts based on polymeric ionic liquids were synthesized and applied into selective oxidation of benzyl alcohol. Polymeric ionic liquid microspheres (PILM) were prepared by radical polymerization, and then the cations in the imidazole ring were exchanged with the metal anions. After that, the metal anions were reduced to Pd nanoparticles that was supported on the surface of PILM. This metal loading method favored the maximum amount of supported Pd nanoparticles that were uniformly distributed on the surface of PILM. In addition, the introduction of CeO2 prevented the aggregation of Pd nanoparticles and finally formed PILM/Pd/CeO2 catalysts with a core-shell structure. The performance of the PILM/Pd/CeO2 catalysts was evaluated by changing the [K2CO3] : [alcohol] molar ratio, reaction temperature and oxygen flow rate in the oxidation reaction of benzyl alcohol. The conversion and selectivity under the optimal reaction conditions reached 48% and 98% respectively The catalysts were effective and reusable after 5 cycles of experiments. In the end, a mechanism underlying the reaction pathway in benzyl alcohol oxidation was put forward.

The inhibition effect of three inhibitors with different chain lengths of their ether groups on Q235 steel in 0.5 M HCl solution at 318 K was determined by means of weight loss measureme nt, electrochemical methods (Tafel and EIS) and surface analysis (SEM). Moreover, the further study of corrosion inhibition mechanism was also conducted by computational methods (Quantum chemical calculations and Molecular dynamics simulations). Results reveal that the three inhibitors exhibit an excellent inhibition performance for carbon steel, and the corrosion inhibition efficiency of the three inhibitors increases with the increase of the chain length, which favors the formation of a protection film adsorbed on the surface. Analysis of polarization data informs that the adsorption type of three inhibitors basically obeys the Langmuir monolaye r adsorption, which is mainly of chemisorptive nature. Computational methods also tell that the three inhibitors possess a high reactivity and strong interaction with the iron surface, furthermore, the interaction is increased with the increase of the chain length of three inhibitors. The conclusion is in good agreement with the experimental results.

Enhancing the kinetics of electrocatalytic water splitting, including the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), under alkaline conditions is of key importance for producing high purity and renewable hydrogen on a large scale. Owing to their unique structural features, two-dimensional (2D) heterostructures have been regarded as promising next-generation electrocatalysts for overall water splitting. Herein, we successfully synthesized three-dimensional (3D) flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres assembled from heterostructural 2D nanosheets. Benefiting from well-exposed interfaces and favorable diffusion channels, the as-prepared 3D flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres manifest excellent overall water splitting performance in an alkaline solution with a low Tafel slope of 71 and 41 mV dec−1 for oxygen and hydrogen evolution reactions, and show significantly improved long-term durability. Furthermore, the 3D flower-like Co–Ni–P/MoS2 heterostructural hybrid spheres used in both the anode and cathode show a low cell voltage of 1.53 V at a 10 mA cm−2 current density. Using DFT calculations, we found the outstanding chemisorption of hydrogen and oxygen-containing intermediates making Co–Ni–P/MoS2 heterostructures an efficient bifunctional overall electrochemical water splitting catalyst. In summary, this work opens up an important direction for exploring efficient and durable bifunctional electrocatalysts for the overall water splitting.

We report a facile one-pot solvothermal synthesis of NiPd alloy homogeneously encapsulated between reduced graphene oxide sheets and N-doped carbon layers (rGO@NiPd@NC) with sandwich structure. In this study, dopamine served as both carbon-nitrogen source and green reagent, which cannot only form N-doped carbon layers encasing metal nanoparticles through high-temperature roasting but also co-reduce metal ions to form NiPd alloy. The rGO@NiPd@NC nanocomposite exhibits enhanced hydrogen evolution reaction (HER) activity with a small overpotential of 56 mV at 10 mA cm−2 and a Tafel slope approaching 33 mV dec−1 in acidic aqueous media, which are similar to the HER activity of commercial Pt/C catalyst (52 mV at j = 10 mA cm−2; Tafel slope, 31 mV dec−1). Additionally, the electrocatalyst which reveals excellent electrochemical stability is reflected in that the polarization curve shows negligible difference after 1000 cycles and the current density only slightly decreases within 20 h test, providing more possibilities for practical application in the future.

CaO and Fe₂O₃ are effective mineral sorbents to inhibit the damage of arsenic and selenium release into the atmospheric environment. Density functional theory was applied to explore the adsorption mechanism of different arsenic and selenium species (atom, hydride, oxide, and chloride) on CaO and Fe₂O₃ surfaces. The effect of the As₄O₆ cluster on the adsorption behavior of CaO and Fe₂O₃ surfaces was also examined. The results show that the O top sites serve as the active sites for arsenic and selenium atom adsorption on the CaO(001) surface. For the Fe₂O₃(001) surface, the adsorption energy of the As atom at the Fe top and O bridge site can reach −381.38 and −439.55 kJ/mol, respectively. The results show that the Fe top site and O bridge site are both effective chemical adsorption sites. CaO and Fe₂O₃ also exhibit a good performance to adsorb atomic arsenic and selenium under the condition of multicoverage. In addition, the interactions between two adsorbents and complex arsenic/selenium species are weakened in different degrees, but still belong to chemical adsorption. The adsorption of the As₄O₆ cluster on the CaO surface is mainly attributed to the interaction between As atoms and O atoms on the CaO surface. The As₄O₆ adsorption on the Fe₂O₃ surface depends on the interaction between O atoms of As₄O₆ and Fe atoms on the Fe₂O₃ surface. However, the interactions can both lead to the formation of more stable arsenate, which contributes to the reduction of detrimental arsenic release.

A core-shell structure Au-based catalysts mSiO2/Au/Co3O4 HS were successfully derived from in-situ growth ZIF-67 hollow spheres, which were synthesized by a one-step soft template method. The samples were characterized by SEM, TEM, EDX, XPS, XRD and BET to confirm its successful preparation and structural features. The catalytic performance of the catalysts were evaluated by liquid phase oxidation of benzyl alcohol to benzaldehyde with O2 as the oxidant under alkaline conditions. The experimental results illustrated that reaction conditions, including effect of catalyst amount, oxygen flow rate, reaction temperature and reaction time, were optimized to be 40 mg, 50 ml/min, 140 °C and 5 h, respectively. Meanwhile, 55% conversion of benzyl alcohol and 84% selectivitiy to benzaldehyde together with the excellent reusability and stability were achieved under optimal reaction conditions, which was attributed to the core-shell structure leading to the encapsulation of Au NPs and provision of multiple active reaction interface. Based on the intermediates formed from the de-protonation of substrate, a plausible oxidation reaction mechanism with mSiO2/Au/Co3O4 HS catalysts was tentatively proposed to study the relationship between structure and catalytic performance.

Herein, 3D hollow-sphere structure graphitic carbon nitride (g-C3N4) with large specific surface area and high porosity is synthesized through a mild, heat polymerization, template-free route. The as-prepared hollow-sphere structure can be used as a substrate material for uniformly dispersing Pd nanoparticles to enhance the absorption of visible light and expose more active sites. Pd nanoparticles as electron acceptor are implanted into g-C3N4, which increases the trapping capability of capturing transition electrons to gain more photogenerated carriers participating in surface reactions. Therefore, the estimated charge separation lifetime of Pd/SCN (10 h) investigated by transient absorption spectroscopy was 1.4 ns ± 338.0 ps, which is only half of SCN. Benefiting from the unique structure and the excellent optical performance, the obtained Pd/SCN composites exhibited prominent photocatalytic hydrogen evolution performance under visible light irradiation. Especially, the photocatalytic hydrogen rate of Pd/SCN (10 h) reached 267.9 µmol/h, almost 10 times higher than the Pd/2D g-C3N4. Simultaneously, a possible mechanism for photocatalytic H2 reaction was proposed based on the characterization results.

Carbon doped honeycomb-like graphitic carbon nitride (g-C3N4) was prepared by one-step thermal polymerization, which derived from chitosan as a carbon source together with the melamine-cyanuric acid complex as a supramolecular precursor. Interestingly, the carbon doped g-C3N4 displayed an increased specific surface area and a more negative conduction band energy level, which not only provided a large number of reaction sites for the photocatalytic hydrogen production, but also effectively enhances the separation of photogenerated electrons-holes. And the experimental results showed that the hydrogen evolution rate of the optimal sample was as high as 320 μmol·h−1, which is 29.10 times than that of bulk g-C3N4 (11 μmol·h−1). More importantly, this work may provide a promising idea for the design of efficient g-C3N4 by controlling the material morphology and combining the electronic modulation strategy.

As one of the ideal catalysts, noble metal materials can realize the conversion from benzyl alcohol to benzaldehyde. However, in previous reports, the loss of surface noble metal is one of the important reasons for the decrease in reaction performance. Here, a simple method was reported for stepwise fabrication of SiO 2 @Co 3 O 4 /Au@m-SiO 2 catalysts with core–shell structure. On the one hand, the core–shell structure provided abundant reaction sites for the oxidation of benzyl alcohol to benzaldehyde. On the other hand, the outer layer of m-SiO 2 effectively prevents the loss of Au nanoparticles. In this process, we studied the effects of multiple factors on the target reaction by controlling a single variable. The experimental results show that under the optimal conditions (the catalyst dosage, reaction temperature, reaction time and O 2 flow rate are 40 mg, 160 °C, 6 h, 60 ml/min, respectively), the conversion rate of the target reaction reaches 58% and the selectivity is as high as 82%. In the end, a mechanism was put forward to illustrate the underlying reaction pathway in benzyl alcohol oxidation.

The first snail shell-shaped helical polyacetylenes (SHPAs) were synthesized from the copolymerization between l-serine-grafted propargylamine (LSA) and propargylamine (PA). The novel structure was obtained at the monomer input proportion of 50%. The monomer (LSA) and copolymers (poly(LSAm-co-PAn)) were characterized by 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, circular dichroism and transmission electron microscopy. The infrared emissivity of poly(LSA50-co-PA50) investigated at 8–14 μm was 0.451, which was much lower than the other copolymers. This was because the poly(LSA50-co-PA50) could form the obvious intramolecular interaction and self-assembled to a snail-shell shape by intermolecular hydrogen bonding in MeOH solution. Meanwhile, the conjugation performance of the main chain was enhanced. Consequently, the abundant hydrogen bonds formed through N–H and C=O bonding and the strong conjugate properties both could decrease the unsaturation degree, as well as change the heat conduction mode in the molecules, thereby reducing the infrared emissivity. This strategy provided a new direction to achieve the controllable infrared stealth.

Herein, a novel strategy is established to synthesize Mo-doped graphitic carbon nitride (g-C3N4) with excellent photocatalytic activity through a green approach of biological template. The addition of biotemplates provides a microenvironment for the formation of hydrogen bonds in which the flower-like g-C3N4 is formed by self-assembly between precursors, which not only increases the specific surface area of the material but also exposes more catalytic activity edge. Benefiting from the non-localized of Mo(VI) 4d orbital, Mo-doped g-C3N4 constructs a suitable band structure and a built-in electric field that promotes electron delocalization, which improves the absorption range of visible light and separation efficiency of photo-generated electron-hole pairs. Subsequently, a possible chelation-hydrogen bond coordination mechanism was proposed based on the characterization results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and 15N solid-state NMR (15N NMR). As a result, the π-conjugated system of g-C3N4 was extended by forming a chelate centered on Mo(VI). Photocatalytic hydrogen evolution (PHE) showed that the optimal hydrogen evolution rate of Mo-doped g-C3N4 was as high as 2008.9 umol/g·h, which was 9.6 times than that of bulk g-C3N4.

Carbon nitride is a promising candidate for photocatalysis but exhibits the limited activity due to the poor mass rate and insufficient light harvesting properties. Herein, an efficient synthesis a...

Hydrogen is a source of sustainable and clean energy poised to replace fossil fuels. Bifunctional electrocatalysts are actively pursued to simultaneously drive the two key reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), for hydrogen production by electrolysis water. One of the most promising candidates based on bimetallic layered double hydroxide salts (LHSs) and cobalt-based organic framework (ZIF-67) suffer from poor interface coupling. Herein, we present a new approach based on fusing NiCo LHSs nanowire arrays with ZIF-67 to fabricate three-dimensional flower-like structures on a Ni-Fe foam support. To improve interfacial coupling and catalytic performance, simple oxidation, carbonization, sulfurization, and selenization are performed to study the effects of different post-treatments and discover the optimum bifunctional electrocatalysts. The optimized S-doped catalyst reveals the highest electrocatalytic characteristic quantified by the low overpotentials of 170 and 100 mV for OER and HER at 10 mA cm -2 in 1 M KOH, respectively. This outstanding electrocatalytic property is ascribed to strong interfacial coupling between the NiCo-LHSs and ZIF-67 derivatives, as well as the rational electronic structures, dense catalytic active sites, and large specific surface area. This work opens new prospects for fabricating efficient and low-cost electrocatalysts for renewable hydrogen energy production.

A series of fluorine-silicon block urethane acrylates (PSi-FMPG-IPDI-HEMA) were synthesized from hydroxypropyl-terminated polysiloxane (PSi), newly-prepared fluorodiol (FMPG), isophorone diisocyanate (IPDI) and hydroxyethyl methacrylate (HEMA). Their molecular structures were characterized by Fourier transform infrared and gel permeation chromatography. The compatibility of the oligomers with HFMA was validated using UV–vis transmittance analysis. The thermal stability, water and chemical resistance, contact angles and anti-adhesive performance of the films were measured. It was found all the films had good thermal properties, and excellent water and chemical resistance. The FMPG content affected the surface energy and anti-adhesive performance of the films. The films with more FMPG presented lower surface energy, lower peel strength, and higher residual adhesion. More importantly, the release films designed based on the fluorine-silicon block urethane acrylates had tremendous application potential.

The exploration of high-efficiency electrocatalysts for the hydrogen evolution reaction (HER) is of great significance for sustainable energy conversion applications, yet it remains a grand challenge. Herein, a facile and rapid strategy to synthesize ultrafine PtNi nanoparticles (NPs) anchored on N-doped graphene (rGO(N)) (labeled as PtNi/rGO(N)) at room temperature is demonstrated. (3-Aminopropyl) triethoxysilane (APTES) is selected as an effective nitrogen source to form two kinds of nitrogen (doping N and amine N) simultaneously for fabricating a rGO(N) matrix during the chemical reduction process. Benefiting from the bimetallic synergistic effect and strong metal–support interactions, this composite is expected to accelerate H+ adsorption and H2 desorption and reduce the transport resistance of electrons and hydrogen intermediates. As a consequence, the PtNi/rGO(N) with ultralow Pt loading amount (1.2 μg per electrode area (cm2)) exhibits extraordinary catalytic activity with a small overpotential of 98 mV at a current density of 10 mA μgPt−1 and an exceptional Tafel slope of 42.7 mV dec−1 for HER, exceeding the incumbent commercial Pt/C catalyst. Moreover, the PtNi/rGO(N) also displays excellent stability with negligible current degradation during a continuous operation for 20 h. The present work would be proposed as an elegant platform toward the exploration of efficient HER electrocatalysts for various renewable energy conversion applications.

Herein, a novel strategy was proposed for the fabrication of hierarchical porous silica materials templated by a poly ionic liquid (PIL, a copolymer of 1-butyl-3-vinylimidazolium bromide and acrylamide) and P123 (PEO20PPO70PEO20). The PIL acts as a co-solvent as well as a co-template in the system. The effects of the concentration of the PIL and pH on the morphology and structure of silica materials were systematically investigated. Hierarchical porous silica materials were characterized by X-ray diffraction, N2 adsorption–desorption, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. Moreover, the results demonstrated that the porous silica materials were equipped with a dual-mesoporous channel structure and possessed a high surface area and large pore volumes up to 1274 m2 g−1 and 1.41 cm3 g−1, respectively. Furthermore, a high-performance catalyst-based supported ionic liquid phase (SILP) was obtained by surface modification with the IL (1-(tri-ethoxy-silyl-propyl)-3-methylimidazolium chloride) of the carrier and anion exchange with HPW. Catalytic performances were investigated in the alkylation of styrene with o-xylene. Moreover, it was found that the as-synthesized catalysts showed high catalytic performance in terms of styrene conversion and selectivity to 1-phenyl-1-xylyl ethane (PXE). Specifically, the catalyst PIL-1.0g-2-IL-HPW showed excellent activities in both the yield (91.5%) and selectivity (96.8%) for this alkylation reaction.

Background The role of the microbiota in the pathogenesis of chronic obstructive pulmonary disease (COPD) following exposure to ambient particulate matter (PM) is largely unknown. Methods Fifty-four male Sprague-Dawley rats were exposed to clean air, biomass fuel (BMF), or motor vehicle exhaust (MVE) for 4, 12, and 24 weeks. We performed pulmonary inflammation evaluation, morphometric measurements, and lung function analysis in rat lung at three different times points during exposure. Lung and gut microbial composition was assessed by 16S rRNA pyrosequencing. Serum lipopolysaccharide levels were measured and short-chain fatty acids in colon contents were quantified. Results After a 24-week PM exposure, rats exhibited pulmonary inflammation and pathological changes characteristic of COPD. The control and PM exposure (BMF and MVE) groups showed similar microbial diversity and composition in rat lung. However, the gut microbiota after 24 weeks PM exposure was characterized by decreased microbial richness and diversity, distinct overall microbial composition, lower levels of short-chain fatty acids, and higher serum lipopolysaccharide. Conclusion Chronic exposure to ambient particulate matter induces gut microbial dysbiosis and metabolite shifts in a rat model of chronic obstructive pulmonary disease.

A series of novel water-soluble amphiphilic copolymers containing ciprofloxacin (CPF) and quaternary ammonium salts were prepared by the free-radical copolymerization of methacrylate monomers with CPF, quaternary ammonium salt (QAS) monomers and butyl acrylate (BA). The copolymers were characterized by 1H-NMR, charge density and UV measurements. The antimicrobial activities of the copolymers, based on the minimum inhibition concentration (MIC) against Escherichia coli (E. coli), varied with hydrophobic BA content in the copolymers. The incorporation of the antimicrobial moiety ciprofloxacin further enhanced the antibacterial activities of the copolymers, reducing the MIC to 4.0 ppm. The UV260 absorption measurements were applied to reveal the dynamic antimicrobial process of the copolymers. The results of inhibition zones and shaking flask methods of antimicrobial-modified fibers showed that the copolymers had excellent antimicrobial activities when applied to cellulose fibers. In the presence of 2 wt% (based on oven-dried fibers) of the copolymer, the growth inhibition reached 100%.

Developing bifunctional electrocatalysts of high-efficiency and new structures for overall water splitting are highly desirable and ongoing challenge. Herein, CoxNi10-x layer double hydroxide salts with controllable structure and morphology induced by 2-methylimidazole to derive ZIF-67 on Ni/Fe foam is reported. The as-prepared 3D CoxNi10-x layer double hydroxide microspheres are constructed by self-assembly of 2D nanoflake and 1D nanorod with ZIF-67 particles due to the double influence of Ni and 2-methylimidazole. It is discovered that the Ni and 2-methylimidazole can simultaneously modulate morphology and structure of CoxNi10-x layer double hydroxide to distinctly increase the electrochemical active surface area for exposing more accessible active sites. Notably, the 3D microsphere heterogeneous catalysis of the self-assembly combines the merits of low dimensions (1D and 2D) materials, providing high structural void porosity and fast charge transport channels. Particularly, the Co7Ni3 layer double hydroxide salts@ZIF-67/Ni/Fe foam exhibits the highest electrocatalytic activity with the lower overpotentials of 260 and 165 mV toward oxygen evolution reaction and hydrogen evolution reaction at current density of 10 mA cm−2, respectively. The outstanding activity originates from the strong electronic coupling between the 3D microsphere and ZIF-67. This work can bring a new prospect for fabricating highly-active and new structure electrocatalysts.

In this work, g-C3N4 with different morphologies is prepared using melamine as precursor via self-assembly and calcination. Compared with pristine g-C3N4, the resultant materials possess thinner lamellar structure and abundant nitrogen defects. Hydrolysis of partial melamine occurs in a hydrothermal process, and a consequent supramolecular intermediate is formed between melamine and its hydrolysates via hydrogen bonding. In addition to enlarging the π–π conjugated systems of the polymer, the formation of intermolecular hydrogen bonds is also interesting for increasing the lifetime of fluorescence as well as for decreasing the recombination rate of electron–hole pairs. Optical absorption characterization indicates that the samples formed by surface self-assembly show remarkably extended light absorption in the visible-light region in comparison with the original g-C3N4. Under visible-light irradiation, all modified materials have outstanding photocatalytic activity, especially the optimally modified cataly...

Tunable and high-efficiency electromagnetic wave (EMW) absorption materials composed of a three-dimensional (3D) hierarchical reduced graphene oxide (RGO) aerogel network entrapped with TiO2/Ti3C2Tx hybrids were fabricated by a hydrothermal method and a mild chemical reduction treatment. The incorporation of the TiO2/Ti3C2Tx micronanoheterostructure and construction of the 3D well-designed hierarchical interconnected network can significantly reduce the agglomeration of RGO sheets together with the beneficial effect of a better impedance match. When the filler loading is 10 wt %, the maximum reflection loss of the composite aerogel reaches up to −65.3 dB with a matching thickness of 2.5 mm. Meanwhile, the effective absorption bandwidth (RL < −10 dB) is 4.3 GHz with the coating thickness of only 2.0 mm, and the tunable absorption bandwidth achieves at 13.74 GHz via modulating the absorber thicknesses in a range from 1.5 to 5.0 mm. The enhanced EMW absorbing performance is closely related to highly porous c...

Mesoporous carbon nitride with novel morphology has been successfully fabricated by using ionic liquid and supramolecular precursor cyanuric acid-melamine complex as the template and precursor, respectively. The texture of carbon nitride is controlled by adjusting the ionic liquid concentration and type. The results find that a disordered hollow carbon nitride box morphology with pores in the wall can be obtained under lower IL1 concentration. With increasing of ionic liquid content, the texture turns to be a layered structure. The disordered nanosheets and hollow tube with large pores in the shell can be fabricated by using IL-2 and IL-3 as templates, respectively. Besides, as-prepared mesoporous carbon nitride samples display the excellent light harvesting properties and fast separation rate of photogenerated carrier. Moreover, mesoporous carbon nitride CN-0.1 exhibits a higher photocatalytic hydrogen evolution rate (120.3 μmol h–1) under visible light irradiation owing to the special structure and the ...

Imidazole (IMI)-based polyethylene glycol monomethyl ether (MPEC-IMI) as a novel green corrosion inhibitor was synthesized to protect the Q235 steel in 0.5 M HCl corrosive medium at 318 K. The inhibition performance of MPEC-IMI was investigated by weight loss measurement, the electrochemical method (Tafel and EIS) and surface analysis (SEM and EDX). The results reveal that the MPEC-IMI shows enhanced anticorrosion performance for carbon steel, which is attributed to the formation of the adsorptive protection film on the surface, and the type of adsorption basically obeys the Langmuir monolayer adsorption. Furthermore, when the concentration of MPEC-IMI is 300 mg L−1, the corrosion inhibition efficiency can reach up to 92.00%. In support of further study of the corrosion inhibition behavior by virtue of quantum chemical calculation and molecular dynamics simulations, the results show that the MPEC-IMI molecule has high reactivity and strong interaction on the iron surface.

In this study, multilayer sandwich heterostructural Ti3C2Tx MXenes decorated with polypyrrole chains have been synthesized successfully via HF etching treatment and in-situ chemical oxidative polymerization approach. The hybrids were investigated as EM wave absorbers for the first time. It is found that the composites consisting of 25 wt% Ti3C2Tx/PPy hybrids in a paraffin matrix exhibit a minimum reflection loss of −49.2 dB (∼99.99% absorption) at the thickness of 3.2 mm and a maximum effective absorption bandwidth of 4.9 GHz (12.4–17.3 GHz) corresponding to an absorber thickness of 2.0 mm. Additionally, a broad effective absorption bandwidth of 13.7 GHz (4.3–18.0 GHz) can be reached up by adjusting the thickness from 1.5 to 5.0 mm. Furthermore, the highest effective absorption bandwidth of 5.7 GHz can be reached when the mass fraction is 15 wt%. The enhanced comprehensive electromagnetic wave absorption has close correlation with the well-designed heterogeneous multilayered microstructure, generated heterogeneous interfaces, conductive paths, surface functional groups, localized defects and synergistic effect between laminated Ti3C2Tx and conductive polypyrrole network, which significantly improve impedance matching and attenuation abilities. The superior absorbing performance together with strong absorption and broad bandwidth endows the Ti3C2Tx/PPy hybrids with the potential prospect to be advanced EM wave absorbers.

SPICE modeling of silicon carbide (SiC) MOSFET considering the influence of interface traps has been carried out, which is able to describe the characteristics of the MOS transistors in all operation modes at different interface trap densities and measurement temperatures. This modeling employs the SPICE level-1 model of MOSFET, but the constant mobility in the piecewise current equations has been replaced by the advanced mobility expression, which can exactly reflect the effect of SiC/SiO2 interface traps on the electrical characteristics of SiC MOSFET. Key parameters in the advanced mobility model are obtained according to charge-sheet model (CSM) of MOS system. The static characteristics of the developed SiC MOSFET model have been validated with the production Datasheet, and the dynamic characteristics have been experimentally verified in Boost converter. Based on the developed model, the effect of SiC/SiO2 interface-trap densities on the switching performances of SiC MOSFET has been quantitatively discussed, and reasonable gate driving voltage of SiC MOSFET with different interface-trap densities has been revealed.

Cross-linked poly acidic ionic liquids (MPM-C6V-SO3CF3-IL) with mesoporous and macroporous network structure have been synthesized in different solvents. The novel solid acid catalyst with special network structure has a large surface area (103.83 m2/g), large pore volume (0.72 cm3/g) and abundant mesopores and macropores, which help to improve the contact between active site and reactants. Catalytic performance of catalyst was investigated through alkylation of o-xylene and styrene. Different reaction parameters specifically solvent on obtained catalyst and production of PXE were systematically investigated. Under optimal reaction conditions (reaction time was 3 h, reaction temperature was 120 °C, catalyst amount was 0.17 g (0.5 wt%), and o-xylene/styrene mass ratio was 7.5:1), a high conversion of styrene (100%) and 1,2-diphenylethane (PXE) yield of 99.67% was obtained, which is superior to commercial acid in liquid and even previous acids synthesized by our own group. Moreover, catalyst could keep relatively high thermostability under reaction and are easy to be separated and recycled from the solution, which are critical for heterogeneous solid catalysts. Thus, this novel catalyst can be potentially applied in other acidic reactions.

A novel fluorescent-tagged scale inhibitor, the linear-dendritic double hydrophilic block copolymer [acrylic acid (AA)/allyloxy poly(ethylene glycol) polyglycerol (APEG-PG-(OH)n)/8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA) (AA/APEG-PG-(OH)n/PA)] was synthesized by polymerisation of AA, APEG-PG-(OH)n and PA. Structures of APEG, APEG-PG-(OH)n and AA/APEG-PG-(OH)n/PA were determined by 1HNMR. The experiments show that the dosage and the n value of AA/APEG-PG-(OH)n/PA play an important role on CaCO3 inhibition. The polymer AA/APEG-PG-(OH)5/PA displays a 90% inhibition of CaCO3 precipitate formation at a dosage of 8 mg/L. The relationship between the fluorescent intensity of AA/APEG-PG-(OH)5/PA and the dosage of this polymer was studied. The correlation coefficient R of AA/APEG-PG-(OH)5/PA's is 0.9995. The effect on formation of CaCO3 was investigated with combination of XRD and SEM analysis. Finally, the significant cause and mechanism for calcium carbonate inhibition were analysed in depth.

A novel sandwich-structured g-C3N4/Au/BiOCl Z-scheme heterojunction with enhanced visible-light-driven photocatalytic activity was successfully fabricated using the reactable ionic liquid (1-methyl-3-[3’-(trimethoxysilyl) propyl] imidazolium chloride) as the template by a facile photoreduction followed by in situ deposition. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, scanning electron microscope and ultraviolet–visible diffuse reflectance spectroscopy. The role of Au in this system was discussed during the degradation of rhodamine B and tetracycline and photocatalytic hydrogen evolution under visible light irradiation. The influence of BiOCl dosage on the photocatalytic activity was also systematically investigated. The result found that the photocatalytic activity was improved using the as-fabricated CN/Au/BiOCl Z-scheme heterojunction than g-C3N4 or BiOCl. Besides, the fast separation rate of photogenerated electron–hole pairs and the improved light absorption in visible ranges of CN/Au/BiOCl samples might be related to the fact that the construction of Z-scheme could improve the optical and conductive properties and enhance the final photocatalytic property. From the free radicals trapping experiments, it was found that the photogenerated holes of BiOCl were the predominant active species in the photocatalytic process.

A facial, one-step soft templating method to synthesize the hollow mesoporous g-C3N4 spheres with high surface area and high porosity was developed, which taking advantage of both supramolecular assembly of cyanuric acid and melamine through hydrogen bonds and the structure-directing character of ionic liquid. The influence of solvent and ionic liquid content on the assemble behavior of the cyanuric acid-melamine complex is studied in detail, respectively. It is found that the as-prepared hollow g-C3N4 spheres possess plenty of mesopores with a high surface area, which is related to the release of volatile domains and decomposition of ionic liquids. Moreover, as-prepared g-C3N4 exhibit improved light absorption in visible ranges, faster separation rate of photogenerated hole-electron pairs than the bulk carbon nitride. Besides, the as-prepared hollow mesoporous carbon nitride exhibits almost 30 times higher than traditional g-C3N4 which calcined by melamine for the photocatalytic hydrogen evolution reaction under visible light irradiation, which may be caused by the fact that the high surface area is beneficial for improving light absorption in visible ranges, and finally enhancing the H2 evolution rate. This method paves new opportunities for designing other catalysts with high surface area.

A simple and effective one-step method was proposed for the fabrication of dual-mesoporous silica, which was templated by alkoxysilyl-functionalized ionic liquid and cetyltrimethyl ammonium bromide (CTAB), with potential application in alkylation of o -xylene and styrene. Ionic liquid act as both template and silica source in this system. The influence of pH of solvent and concentration of alkoxysilyl-functionalized ionic liquid to the morphology of obtained silica was studied in detail. The results showed that the as-prepared silica materials with core-shell or hollow structure could be fabricated by adjusting the pH and ionic liquid concentration, which is strongly related to the unique features of alkoxysilyl-functionalized ionic liquid with organic silicon chain. The possible mechanism was proposed based on the interaction between ionic liquid and CTAB. This new method is also applicable to synthesize the other hierarchical porous silica materials by using organic silyl functional ionic liquid.