Recycling and utilization of coal gasification residues for fabricating Fe/C composites as novel microwave absorbents

Under the background of a transformation of the global energy structure,coal gasification technology has a wide application prospect,but its by-product,the coal gasification residue(CGR),is still not being efficiently utilized for recycling.The CGR contains abundant carbon components,which could be applied to the microwave absorption field as the carbon matrix.In this study,Fe/CGR composites are fabricated via a two-step method,including the impregnation of Fe^(3+)and the reduction process.The influence of the different loading capacities of the Fe component on the morphology and electromagnetic properties is studied.Moreover,the loading content of Fe and the surface morphology of the Fe/CGR can be reasonably controlled by adjusting the concentration of the ferric nitrate solution.Meanwhile,Fe particles are evenly inserted on the CGR framework,which expands the Fe/CGR interfaces to enhance interfacial polarization,thus further improving the microwave-absorbing(MA)properties of composites.Particularly,as the Fe^(3+)concentration is 1.0 mol/L,the Fe/CGR composite exhibits outstanding performance.The reflection loss reaches-39.3 dB at 2.5 mm,and the absorption bandwidth covers 4.1 GHz at 1.5 mm.In this study,facile processability,resource recycling,appropriately matched impedance,and excellent MA performance are achieved.Finally,the Fe/CGR composites not only enhance the recycling of the CGR but also pioneer a new path for the synthesis of excellent absorbents.

The study of the adductor muscle-shell interface structure in three Mollusc species

The adductor muscle scar（AMS） is the fixation point of adductor muscle to the shell. It is an important organicinorganic interface and stress distribution area. Despite recent advances, our understanding of the structure and composition of the AMS remain limited. Here, we report study on the AMS of three bivalves： Mytilus coruscus,Chlamys farreri and Ruditapes philippinarum. Results showed that there were significant differences among their AMS structures. Both M. coruscus and C. farreri were found to have a columnar layer above the nacreous platelet shell structure at the AMS and this layer was more organized in M. coruscus. There was no distinguishable twolayer structure in R. philippinarum. Atomic force microscopy（AFM） and Fourier transform infrared spectroscopy（FT-IR） results showed that the AMS was much smoother than the nacreous inner shell in all the three species and the AMS had minor different compositions from the nacreous shell layer. SDS-PAGE（sodium dodecyl-sulfate polyacrylamide gel electophoresis） study of the proteins isolated from the interface indicated that there was a 70 k Da protein which seemed to be specifically located to the highly organized columnar AMS structure in Mytilus coruscus. Further analysis of this protein showed it contained high level of Asx（Asp＋Asn）, Glx（Glu＋Gln） and Gly.The special structure and composition of the AMS might play important roles in the stability, adhesion and function at this stress distribution site.

Waste to treasure:Reutilization of fluid catalytic cracking coke block as photothermal conversion material for water evaporation

This study aims to analyze the coking process and propose an effective method for the reutilization of fluid catalytic cracking(FCC)coke block.Herein,we analyzed the basic characteristics and chemical composition of FCC coke blocks.The results showed that the main components were carbon,oxygen,and aluminum,accounting for 60.8%,26.6%,and 11.5%,respectively.Under the conventional catalytic cracking reaction temperature from 500℃ to 600℃,the formation of the first aromatic hydrocarbon was particularly important for the formation of coke.The condensation of oil-gas-entrained catalyst particles and their heavy components was the physical cause of coking,while the dehydrogenation condensation reaction of oil-gas heavy components was the chemical factor.In addition,the membrane prepared by powdered coke had excellent photothermal conversion ability,which could be heated to more than 110℃ within 360 s under two fixed light intensities.The evaporation rate of photothermal water was 5.89 kg m^(2) h^(−1),which has great industrial application potential.These works provide a novel and effective method of separation membrane for the reutilization of FCC coke blocks.

Face-directed Strategy for the Construction of Polyoxovanadate-based Metal-Organic Tetrahedra

Polyoxometalate-based metal-organic polyhedra(MOPs)were of particular concern because of the various exquisite building blocks and the suitable constructional characteristics.To further understand the design and particularity of polyoxovanadate-based MOPs,(NH_(2)Me)_(8){[V_(6)O_(6)(OCH_(3))_(9)(C_(6)H_(5)PO_(3))]_(4)·(BPT)_(4)}·2DMF(HNU-74)and(NH_(2)Me)12{[V_(6)O_(6)(OCH_(3))_(9)(C_(6)H_(5)PO_(3))]4·(HBCBAIP)_(4)}(SO_(4))_(2)·MeOH·DMF(HNU-75)were constructed by a face-directed synthesis strategy.Both structures were assembled with four secondary building units as vertexes and four organic ligands served as faces.Different from HNU-74,HNU-75 showed a carboxyl group free during the coordination process,resulting in the pore channels being blocked and the free carboxyl group linking outwards,paving the way for the formation of the 3D structure.Due to the pore channels of HNU-74,the adsorption of I2 was studied and the adsorption capacity was 148 mg/g.

Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals

The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals(i.e.,illite and kaolinite)were investigated.Sorption and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium,kinetics,and thermodynamics of lambda-cyhalothrin adsorption onto minerals.The results indicate the following:(i)The adsorption processes for the APG system and CSAD/APG system include:rapid adsorption,slow adsorption,and adsorption equilibrium.The adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model,and the adsorption isotherm conforms to the Freundlich model.In addition,the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible(ΔG^0<0),endothermic(ΔH^0>0),and mainly involved chemical bonding(ΔH^0>60).(ii)The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4%and 64.8%,and the corresponding equilibrium adsorption percentages on kaolinite were 40.8%and 61.8%,respectively.Moreover,the pesticide adsorption rate K_(2-CSAD/APG)was faster than K_(2-APG),and its adsorption capacity K_(f-CSAD/APG )was greater than K_(f-APG).Meanwhile,the pesticide desorption K_(fd)in the CSAD/APG system was smaller than that in the APG system.As a result,this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation,since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species.

Metal-Organic Framework-based Wood Aerogel for Effective Removal of Micro/Nano Plastics

The large amount of microplastic pollution in the aquatic environment has been regarded as a major challenge facing the world. Although some traditional water treatment processes can effectively remove microplastics in the millimeter range, research is still needed to solve the problem of removing smaller microplastics. Here, we made a durable zinc metal-organic framework-based composite material ZIF-8@Aerogel by in situ growing ZIF-8 on wood aerogel fibers, which can successfully remove microplastics in simulated water and seawater. The removal efficiencies on micro/nano plastics including poly(1,1-difluoroethylene)(60-110 nm) and polystyrene(90-140 nm) reached 91.4% and 85.8%, respectively. This work is expected to provide a new and efficient way to remove small-sized microplastic particles in the environment.

Preparation and properties of substrate PVA-GO composite membrane for solar photothermal conversion

Solar thermal desalination(STD)is a promising and sustainable technology for extracting clean water resources.Whereas recent studies to improve STD performance primarily focus on interfacial solar evaporation,a non-traditional bottom heating method was designed in this study.Herein,we prepared the polyvinyl alcohol/graphene oxide(PVA-GO)composite membrane and adhered to the bottom of a beaker using crystallized PVA.The GO was loaded on a non-woven fabric and different concentrations of PVA were compared for their effect on the evaporation efficiency.The results showed that the addition of PVA increased the evaporation rate.The surface characteristic of GO membrane without PVA was a fibrous filamentous structure as observed by SEM,whereby the fibers were clearly visible.When the PVA concentration reached 6%,the non-woven fiber was completely wrapped by PVA.Under the action of a fixed light intensity,the photothermal conversion rates of GO,2%PVA-GO,4%PVA-GO and 6%PVA-GO membrane device could reach 39.93%,42.61%,45.10%and 47.00%,respectively,and the evaporation rates were 0.83,0.88,0.94 and 0.98 kg$m-2$h-1,respectively.In addition,the PVA-GO composite membrane showed an excellent stability,which has significance for industrial application.

Facile preparation of covalent organic frameworks@alginate composite beads for enhanced uranium(Ⅵ) adsorption

Covalent organic frameworks(COFs) have broad application prospects in adsorption and separation.Yet,as COFs are generally in powder form,their superior performance at the laboratory scale is difficult to transfer into pilot-or industrial-scale use.Thus,there is a strong and urgent need to structure COFs into monolithic materials.Herein,a facile strategy was developed to prepare COFs@alginate composite beads.Three composite beads comprising different COFs including TpPa-1(2,4,6-triformylphloroglucinol(Tp) and p-phenylenediamine(Pa-1)as monomers),TpDb(Tp and 2,5-diaminobenzonitrile(Db)as monomers) and TpTt(Tp and 1,3,5-triazine-2,4,6-triamine(Tt) as monomers) with controlled COF loading and product size have been facilely achieved via this strategy,validating the applicability of this method.Furthermore,the representative TpDb@alginate composite beads showed good adsorption performance of uranium(VI) in aqueous solution with high adsorption capacity(635 mg·g^(-1)),good interference immunity and recyclability.This work offers a practical approach for incorporation of COFs into polymer matrix,which can serve as potential adsorbents for radioactive wastewater treatment.

Enhancing soil aggregation and acetamiprid adsorption by ecofriendly polysaccharides hydrogel based on Ca^(2+)-amphiphilic sodium alginate

Soil aggregation plays an important role in agricultural production activities.However,the structure of soil aggregation is destroyed by the natural environment and unreasonable farming management,resulting in the loss of water,fertilizers and pesticides in soil.At present,hydrogels have been widely reported to promote the formation of soil aggregation.In this paper,amphiphilic calcium alginate(ASA/Ca^(2+))was applied to promote the formation of soil aggregation and enhance pesticide retention.Initially,an ASA was obtained through the one-pot Ugi condensation(a four-component green chemical reaction).Then,ASA/Ca^(2+) hydrogel is prepared by Ca^(2+) cross-linking.The formation of soil aggregation was determined through the Turbiscan Lab Expert stability analyzer,Confocal Laser Scanning Microscope(CLSM),and Transmission Electron Microscope(TEM).And the effect of soil aggregation on acetamiprid environmental behavior was investigated by adsorption kinetics,adsorption isotherms,and leaching.The results shown that the three-dimensional network structure of ASA/Ca^(2+) hydrogel can promote the formation of soil aggregation.Aggregate durability index(ADI)was 0.55 in the presence of ASA/Ca^(2+) hydrogel,indicating that amphiphilic hydrogel can enhance the stability of soil aggregation.The adsorbing capacity of acetamiprid was 1.58 times higher than pure soil,and the release of acetamiprid only about 20%in the presence of ASA/Ca^(2+) hydrogel.These results would be helpful for the formation of soil aggregation and pesticides adsorption on soil aggregation.Thus,ASA/Ca^(2+) hydrogel is likely to improve soil quality,simultaneously it can minimize the mobility of pesticides in the agricultural system.

Pillared-layer MOF Based on Template-directed Method: Synthesis, Structure and Proton Conduction Properties

By using Co(NH3)63+as the template,a new complex HNU-38 was synthesized under hydrothermal reaction through the adoption of H3BTC and Cl-as the ligands(H3BTC=1,3,5-benzenetricarboxylic acid).HNU-38 crystallized in the monoclinic system,P21/c space group with a=9.9696(3),b=17.0580(6),c=16.5263(6)?,β=100.400(2)o,Z=4,V=2764.31(16)?3,Mr=883.63,Dc=2.123 g/cm3,F(000)=1736,S=0.920,R=0.0358 and wR=0.0838(Ⅰ>2σ(Ⅰ)).In HNU-38,the Cd2+and BTC3-were linked together to form layers with Cl-serving as the pillar.It should be noted that(H2O)n chains were found in the channels and play a co-templating role along with the Co(NH3)63+cations in HNU-38,and the proton conduction properties were investigated.

Synergistic effect of cubic C_(3)N_(4)/ZnO/C hybrid composite for selective detection of sulfur dioxide

With the development of industrial society,the emission of SO_(2) gas increases sharply.Because of the harm of SO_(2) to the environment and human health,it is crucial to detect and capture SO_(2),especially to develop gas sensing materials with good selectivity and durability to SO_(2).In this work,we prepared a C_(3)N_(4)/ZnO/C hybrid,MFM@IRMOF-3-T,for SO_(2) monitoring by annealing a composite of melamine-formaldehyde resin microsphere (MFM) and isoreticular metal-organic frameworks (IRMOF)-3.

Two polyoxovanadoborates with over 100 nuclei assembled from a {V_(14)Co_(12)B_(72)} cluster

Combining theoretical prediction and experimental exploration, the first sandwich-type polyoxovanadoborate(POVB) with an odd number of nuclei, [V_(11)B_(26)O_(73)(OH)_(10)]^(8-)(1), was discovered under hydrothermal conditions. Density-functional theory(DFT)gives a rationalization for the existence of this structure and the structural feature is consistent with the {V_NB_(2N+X)}(X = 2, 4, 6, 8)general formula. Excitingly, when Co and 1,10-phenanthroline(phen) are introduced into the synthesis of vanadoborates system,a 100-nuclei [Co_6(phen)_(10)(H_(2)O)_8][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·28H_(2)O(2) and a 102-nuclei [Co_6(phen)_(14)(H_(2)O)_(4)][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·23H_(2)O(3) with the same core structure of [V_(14)Co_(12)B_(72)]^(12-)are obtained. The vase-shaped [V_(14)Co_(12)B_(72)] polyanion is a multilayered sandwich-type structure containing seven distinct structural layers and is the largest known POVB. Furthermore, 2demonstrates exceptional thermal and chemical stability and serves as an efficient and stable catalyst for the photoreduction of carbon dioxide.

Enhancing oxidative desulfurization of polyoxometalate by integrating with a self-reductive framework

With the strict control of sulfur content in fuels,oxidative desulfurization(ODS),a promising desulphurization technology,needs to be continuously developed.In this study,we integrated multiple approaches(fabricating a porous structure,increasing phosphomolybdic acid(PMo)loading,improving amphiphilicity,and enhancing the intrinsic activity of PMo using a reductive framework)into PAF-54 carriers to improve ODS catalytic ability.The catalytic performance suggested that PAF-54 was not simply used as a carrier for PMo by physical integration.During the binding process,electron transfer between PAF-54 and PMo formed Mo^(5+)with superior catalytic activity.Owing to the presence of PAF-54,the catalytic activity of PMo as the active component qualitatively improved to achieve rapid and efficient desulfurization.More importantly,we found that other nitrogen-rich porous organic polymers can also reduce some of Mo^(6+)in PMo during loading,and its formation mechanism was investigated.This work provides a feasible strategy for designing highly efficient DOS catalysts.

[Co(NH_3)_6]_2[Cd_8(C_2O_4)_(11)(H_2O)_4]·8H_2O: A 5-connected sqp topological metal-organic framework co-templated by Co(NH_3)_6^(3+) cation and (H_2O)_4 cluster

In our efforts to construct new metal-organic frameworks （MOFs） by template-directing method, a new cadmium oxalate, [Co（NH3）612[Cds（C204）ll（H20）4].8H20 （denoted HNU-1 ）, has been synthesized under hydrothermal condition in the presence of C0（NH3）6C13, The crystal structure of HNU-1 was determined by single-crystal X-ray diffraction （monoclinic, C2/c）, a = 11.126（2）A, b = 17.361 （4）,A, c = 16.119（3）A, fi = 102.40（3）, V = 3040.8（10） A and Z = 8. The open framework of HNU-1 contains 12-ring channels and exhibits a 5-connected sqp topological network with dinuclear Cd（ll） clusters acting as nodes. The Co（NH3）63＋ cations and unusual hydrogen-bonded （H20）4 clusters are found in the 12-ring channels with an alternative arrangement. It is believed that the （H20）4 clusters play a co-templating role in the crystallization of HNU-1.

Decorating Covalent Organic Frameworks with High-density Chelate Groups for Uranium Extraction

The extraction of uranium from aqueous solution is highly desirable for sustaining the increasing demand for environmental safety and nuclear fuel.Herein,we report a strategy using a two-step covalent modification for the synthesis of covalent organic frameworks(COFs)with high-density amidoxime chelate groups at periphery.The introduction of dense amidoxime groups plays a pivotal role in uranium adsorption.The resulting COF exhibits strong affinity with the distribution coefficient of 5.2×104 mL/g and a high adsorption capacity of 319.9 mg/g.The strategy could be expanded to identify and remove different contaminants by introducing special functional groups.