查看更多>>摘要：Hydrogen energy stands out as one of the most promising alternative energy sources due to its cleanliness and renewability.Electrocatalytic water splitting offers a sustainable pathway for hydrogen production.However,the kinetic rate of the hydrogen evolution reaction(HER)is sluggish,emphasizing the critical need for stable and highly active electrocatalysts to facilitate HER and enhance reaction efficiency.Transition metal-based catalysts have garnered attention for their favorable catalytic activity in electrochemical hydrogen evolution in alkaline electrolytes.In this investigation,flower-like nanorods of MoS2 were directly synthesized in situ on a nickel foam substrate,followed by the formation of MoP/MoS2-nickel foam(NF)heterostructures through high-temperature phosphating in a tube furnace environment.The findings reveal that MoP/MoS2-NF-450 exhibits outstanding electrocatalytic performance in an alkaline milieu,demonstrating a low overpotential(90 mV)and remarkable durability at a current density of 10 mA/cm2.Comprehensive analysis indicates that the introduction of phosphorus(P)atoms enhances the synergistic effect with MoS2,while the distinctive flower-like nanorod structure of MoS2 exposes more active sites.Moreover,the interface between the MoP/MoS2 heterostructure and NF facilitates electron transfer during hydrogen evolution,thereby enhancing electrocatalytic performance.The design and synthesis of such catalysts offer a valuable approach for the development of high-performance hydrogen evolution electrocatalysts.
查看更多>>摘要：The abuse of tetracycline antibiotics has caused great harm to human health and ecosystems.Developing inexpensive,convenient and sensitive methods for the detection of tetracycline antibiotics is highly desirable.Herein,based on the H4ddp ligand[H4ddp=3-(3,5-dicarboxyphenyl)pyridine-2,6-dicarboxylic acid],two novel zinc-based metal-organic frameworks(MOFs){[Zn3(ddp)2(H2O)4]·3H2O}n(Zn1-ddp)and {[Zn3(ddp)2(H2O)4]·3H2O}n(Zn2-ddp)were successfully designed by delicate structural regulation.Both Zn1-ddp and Zn2-ddp exhibited excellent water and chemical stability and showed excellent fluorescence quenching performance for tetracycline antibiotics.Notably,the more advanced framework structure and better fluorescent performance make Zn1-ddp more sensitive than Zn2-ddp in fluorescent detection with a detection limit of 0.29 μmol/L for tetracycline(TC),0.09 μmol/L for doxycycline(DOX),0.10 μmol/L for minocycline(MIN)and metacycline(MEL),0.19 μmol/L for chlortetracycline(CTC),and 0.67 μmol/Lfor oxytetracycline(OTC)among tetracycline antibiotics.The fluorescence quenching mechanism of Zn1-ddp and Zn2-ddp for tetracycline antibiotics detection was deeply investigated.The reasons for the superior detection performance of Zn1-ddp over Zn2-ddp were also analyzed in depth through Fourier transform infrared spectrophotometry(FTIR),X-ray photoelectron spectroscopy(XPS)analysis and framework structure analysis.The developed method opens up a new perspective for antibiotics detection based on zinc-based MOFs.
查看更多>>摘要：Free-standing membranes show extraordinary promise in energy storage applications,however are usually limited by low capacity and poor rate capabilities.Herein,we assembled a series of free-standing MnO2/GO composite membranes with ZIF67 particles embedded between two-dimensional(2D)layers.The particle size of ZIF67 can be adjusted to achieve tunable interlayer spacing.The lithium storage performance of the as-obtained membranes with different interlayer spaces was systematically studied.The MnO2/GO composite membrane embedded with ZIF67 particles with an average diameter of 30 nm(denoted as MnO2/nZIF67/GO)delivers a good long cycling performance,and it retains a capacity of 340.7 mA·h·g-1 after 400 cycles at 0.05 A/g.The MnO2/GO composite membrane embedded with ZIF67 particles with an average diameter of 500 nm(denoted as MnO2/mZIF67/GO)exhibits good rate performance.Regardless of the size of the ZIF67 particles,the performance of the membrane containing ZIF67 is significantly better than that of the membrane without ZIF67,indicating that the ZIF67 particles can enhance the lithium storage performance of the assembled membranes.This work provides a method to fabricate a free-standing membrane for lithium storage with tunable electrochemical performance.
查看更多>>摘要：Inspired by the natural photosynthesis systems,the integrated harnessing and conversion of CO2 present a promising solution for addressing the ever-rising global atmospheric concentration of CO2.Hollow multi-shelled structured(HoMS)photocatalysts,featuring alternating shells and cavities,have recently gained recognition as efficient nano-reactors for capturing CO2 molecules and facilitating effective photoreduction within these hierarchical structures,leveraging the preeminent enrichment effect.In this work,to augment the photocatalytic efficacy of HoMS in CO2 treatment,highly dispersed CuxO nanoparticles(NPs)were incorporated on the CeO2 shells through a polymer-assisted impregnation method to create more active sites and strengthen the interaction between the hetero-shells and CO2 molecules.The photoreduction of the CO2-to-CO rate under a diluted CO2(15％,volume fraction)atmosphere is improved by the introduction of CuxO NPs,with the highest CO yielding rate reaching 120 μmol·h-1·g-1 without any sacrificial reagents.Further comparison experiments and theoretical calculations reveal that the CuxO NPs promote the adsorption of CO2 molecules in HoMS,accelerate the charge transfer efficiency,and stabilize the surface oxygen vacancies(Ovs)during the photoreduction CO2 conversion process.We hope these easy-to-prepare HoMS nanoreactors can contribute to the effective enrichment and valorization of CO2 in industrial exhaust gases.
查看更多>>摘要：Acetone is a tracer for monitoring air quality and a potential breath maker for diabetes.It remains a great challenge for current portable sensors to sensitively and selectively detect acetone at low-ppb(parts per billion)level.Herein,we present an ordered mesoporous nickel oxide(NiO)with both large mesopores and ultrathin crystalline frameworks for the detection of low-ppb acetone.The ordered mesoporous NiO replicas with predominant large mesopores of 11 nm,high specific surface areas of 121-128 m2/g and ultrathin crystalline frameworks of 5 nm were synthesized by the nanocasting method and the crystalline properties of NiO frameworks were adjusted by changing the annealing temperature from 300 ℃ to 750 ℃,which resulted in different contents of oxygen deficient on the surface of ultrathin frameworks.The gas-sensing properties for all the NiO samples were investigated and the ordered large-pore mesoporous NiO(NiO-600)with maximum oxygen deficient obtained at 600 ℃ exhibited the highest response(Rgas/Rair-1=2.9)toward acetone(1 ppm,ppm:parts per million),which is 3.4 and 30 times larger than those for common mesoporous NiO obtained at 300 ℃ and bulk NiO.Notably,a low detection limit(2 ppb),good selectivity and cycling stability were also observed in NiO-600.
查看更多>>摘要：Precipitation and impregnation procedures unevenly distribute metals on zeolite,limiting chemical transformation in Lewis-acid,Brönsted-acid and metal-catalyzed tandem reactions.Although,heterogeneous multitask transition metals oxides@zeolites are promising catalysts for sustainable processes;nevertheless,synthesis is fascinating and complex.Herein,the construction of purposely designed multitask materials segregated in selective shells reveals the remarkable spatial organization of metals-zeolite,resulting in them being suitable for a wide range of tandem reactions.The synthesis of multi-site catalysts begins with a universal wet chemistry approach that yields nickel oxide(NiO)crystals.Then,the NiO crystals are stabilized using cationic dodecyltrimethylammonium bromide,followed by achieving cross-linking carbon growth by emulsion polymerization of glucose in hydrothermal treatment to yield uniformed NiO@carbon spheres(NiO@CSs).Next,sequential adsorption of cobalt cations and colloidal ZSM-5(1％in H2O,mass fraction),followed by calcination in air,yielded NiO@cobalt oxide@zeolite denoted as NiO@Co3O4@ZEO hollow spheres.The hollowing mechanism and materials segregation within shells are revealed by scanning and transmission electron microscopy,thermogravimetric analysis,and X-ray diffraction.The finding advances the rational synthesis of heterogenous core-shell hollow structures for various gas phase catalytic tandem reactions to yield valuable chemicals.
查看更多>>摘要：Nano 3C-SiC@multilayer graphene oxide(NS@MGO)heterostructure was in situ prepared by carbothermal reduction of pyrolyzed precursor composed of highly dispersed cured phenolic resin and silicon dioxide derived from tetraethyl orthosilicate.The heterojunction interface,number of layers of MGO,and defect content in graphene are the three most important factors for promoting photocatalytic activity.Direct contact between 3C-SiC nanograins and MGO layers facilitates the photogenerated electrons to migrate across the heterojunction interface and avoid the formation of SiO2 nanolayers on the surface of SiC nanograins.The number of MGO layers is supposed to be less than ten instead of over-thick MGO.The concentrations of oxygenated components,considered the defect contents,decrease with the increase of sintering temperature for NS@MGO 0.175-T-150,and relative carbon content in the multilayer graphene increases.According to the heterostructures,properties,and photocatalytic reaction performance of the NS@MGO materials,the highest photocatalytic kinetic rate constant of 0.00891/min for NS@MGO 0.175-1500-150 shows that the significant enhancement in photocatalytic degradation activity under visible light(＞420 nm)irradiation is ascribed to the advantageous synergistic effects between the nano 3C-SiC particles and the direct contact multilayer graphene oxide with appropriate layers and sufficient oxygen content of 3.51％(atomic fraction)in MGO.
Muzammil HUSSAINTofik Ahmed SHIFAPratik V.SHINDEPankaj KUMAR...
548-555页
查看更多>>摘要：Interfacial solar desalination is an emerging technology for freshwater production,but the finding of novel solar evaporators is still challenging.In the present research,graphitic carbon foam(CF)was synthesized from the upcycling of waste plastic polyethylene terephthalate(PET)waste bottles functionalized with carrollite CuCo2S4 as a photothermal layer.Analytical characterization[X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)]confirms the functionalization of carrollite CuCo2S4 on graphitic carbon foam.The UV-Vis spectroscopy analysis showed an enhanced optical absorption in the UV-Vis-near IR region(＞96％)for functionalized CuCo2S4-CF foam compared to carbon foam(67％).The interfacial solar desalination experiment presented a significantly enhanced evaporation rate of 2.4 kg.m-2.h-1 for CuCo2S4-CF compared to that of CF(1.60 kg·m-2·h-1)and that of CuCo2S4(1.60 kg·m-2·h-1).The obtained results proved that the newly synthesized CuCo2S4-CF from the upcycled plastic into new material for the photothermal desalination process can enhance the practice of a circular economy to produce fresh water.
查看更多>>摘要：The halide migration effect in mixed-halide lead-based perovskite is a serious problem hindering the development of its display technology.In this study,we have successfully addressed this issue by reporting formadinium(FA)doped mixed-halide perovskite nanocrystals(NCs)with ultra-deep-blue emission of 450 nm,narrow bandwidth of 16 nm,and a high photoluminescence quantum yield(PLQY)of 66％.The perovskite nanocrystal light-emitting diodes(NC-LEDs)using this nanocrystal as an active layer achieved a maximum external quantum efficiency(EQE)of 0.32％,30-fold improved compared to that of pristine and stable electroluminescence(EL)spectra at 450 nm under a 4.9-8.0 V bias.These findings demonstrate the potential of our approach in developing stable and efficient deep blue perovskite NC-LEDs.
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