The efficient production of acetate through electrochemical CO_(2)reduction reaction(eCO_(2)RR)with low energy consumption has consistently been a challenging yet extremely significant task.Current catalysts suffered ...The efficient production of acetate through electrochemical CO_(2)reduction reaction(eCO_(2)RR)with low energy consumption has consistently been a challenging yet extremely significant task.Current catalysts suffered from high energy consumption and low relative purity of acetate product.Herein,we report ultrasmall Cu_(2)O nanoparticles with an average size of 2.5±0.09 nm immobilized on a conductive copper-based metal-organic framework(Cu-THQ)(denoted as Cu_(2)O@Cu-THQ),which attained a Faradaic efficiency of 65(3)%for acetate at a very low potential of-0.3 V vs.RHE with a current density of 10.5 m A/cm^(2).Importantly,as there are no other liquid phase products such as formate,methanol or ethanol,the relative purity of the obtained acetate product was as high as 100%.Taking into account the relative purity of the liquid product,current density,and energy consumption,the performance for electroreduction of CO_(2)to acetate of Cu_(2)O@Cu-THQ is not only much higher than that of the commercial Cu_(2)O nanoparticles,but also higher than those of all reported catalysts.Operando infrared spectroscopy and theoretical calculations indicated that the synergy effect between Cu-THQ and Cu_(2)O promoted the e CO_(2)RR to yield acetate.Specifically,the hydroxyl group on the organic ligand THQ in the Cu-THQ formed hydrogen bond interactions with the key C_(2)intermediates(*CH_(2)COOH and*HOCCOH)adsorbed on Cu_(2)O,which played a crucial role in stabilizing the key C_(2)intermediates and thus reduced the formation energy of the key C_(2) intermediates.展开更多
In this paper,polyamide(PA)woven fabric was used as the base fabric,and polyurethane(PU)solution containing silica nanoparticles(PU@SiO_(2)NPs)was used as the coating solution to prepare composite tent fabric(PA/PU@Si...In this paper,polyamide(PA)woven fabric was used as the base fabric,and polyurethane(PU)solution containing silica nanoparticles(PU@SiO_(2)NPs)was used as the coating solution to prepare composite tent fabric(PA/PU@SiO_(2)).The morphology,structure,and durability of the tent fabric under ultraviolet(UV)radiation,waterstained,or thermal conditions were investigated.The results show that compared with PA/PU fabric without SiO_(2)NPs,when the mass fraction of SiO_(2)NPs in PU coating is 5%,the air permeability of PA/PU@SiO_(2)fabric decreases from about 7.5 to 6.0 nm/s,while the reflectivity to UVvisible light is significantly improved.The surface wettability decreases,as indicated by the average water contact angle(WCA)on PA/PU@SiO_(2)remaining stable at 47°after 9 min.After thermal treatment,the PA/PU@SiO_(2)fabric shows superior mechanical stability.The degradation rate of the tensile strength is only 6.3%,approximately half that of the PA/PU fabric.Meanwhile,the elongation at break increases to 98.9%,compared to 61.8%for the PA/PU fabric.展开更多
As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleat...As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleation of MgB_(2).Herein,amorphous VB_(2)nanoparticles with an average size of approximately 32 nm are synthesized to enhance the hydrogen storage performance of 2LiBH_(4)-MgH_(2)composite.VB_(2),sharing the same hexagonal structure with MgB_(2)with a d-value mismatch ratio of only 2.28%,could serve as effective nucleation sites for promoting the formation of MgB_(2).Theoretical calculations reveal that the introduction of VB_(2)significantly reduces the binding energies of B and Mg,facilitating in situ nucleation of MgB_(2).As a result,after the introduction of VB_(2)nanoparticles,complete hydrogen desorption of 9.23 wt%is achieved for 2LiBH_(4)-MgH_(2)within 2 h at 400℃,which is 4 times shorter than the time required for pure 2LiBH_(4)-MgH_(2),and no nucleation incubation period for hydrogen desorption is observed even at a low temperature of380℃.More importantly,a reversible capacity of9.3 wt%,corresponding to a capacity retention of 100%,could be preserved after 10 cycles of hydrogen storage,demonstrating stable reversible hydrogen storage performance.This study provides a novel technological pathway for improving the reversible hydrogen storage performance of composite metal hydrides and offers significant insights into the development of high-performance hydrogen storage materials.展开更多
Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and struc...Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and structural evaluation utilized XRD,TEM,Raman,FTIR and BET techniques.Cu/TiO_(2)showed rich defects and a higher specific surface area than that of TiO_(2).The 1Cu/TiO_(2)(molar ratio Cu/TiO_(2)of 1/100)showed the best performance to adsorption of CR solution at different reaction conditions(contact duration,CR concentration,adsorbent dose,temperature,and initial pH).Adsorption kinetics and equilibrium isotherms were well-described with a pseudo-second-order kinetics and Freundlich model,respectively.The negative ΔG indicates stable adsorption of CR on the Cu/TiO_(2)surface.The adsorption efficiency only decreases by 6%after 5 cycles of adsorption regeneration.The successful synthesis of Cu/TiO_(2)offers a new possibility to address the problems related to CR dye from aqueous solutions.展开更多
The p-block metal(In,Sn,Bi,etc.)-based electrocatalysts have exhibited excellent activity in the electrocatalytic CO_(2)reduction(ECR)to formate.However,the rapid decrease in catalytic activity caused by catalyst reco...The p-block metal(In,Sn,Bi,etc.)-based electrocatalysts have exhibited excellent activity in the electrocatalytic CO_(2)reduction(ECR)to formate.However,the rapid decrease in catalytic activity caused by catalyst reconstruction and agglomeration under ECR conditions significantly restricts their practical applications.Herein,we developed a sulfur anchoring strategy to stabilize the high-density sub-3 nm In_(2)S_(3)nanoparticles on sulfur-doped porous carbon substrates(i-In_(2)S_(3)/S-C)for formate production.Systematic characterizations evidenced that the as-prepared catalyst exhibited a strong metal sulfide-support interaction(MSSI),which effectively regulated the electronic states of In_(2)S_(3),achieving a high formate Faradaic efficiency of 91%at−0.95 V vs.RHE.More importantly,the sulfur anchoring effectively immobilized the sub-3 nm In_(2)S_(3)nanoparticles to prevent them from agglomeration.It enabled the catalysts to exhibit much higher durability than the In_(2)S_(3)samples without sulfur anchoring,demonstrating that the strong MSSI and fast charge transfer on the catalytic interface could significantly promote the structural stability of In_(2)S_(3)catalysts.These results provide a viable approach for developing efficient and stable electrocatalysts for CO_(2)reduction.展开更多
In this study,the corrosion resistance and the stability of passive films on the laser melting depositionprocessed 316L austenitic stainless steel with varying CeO_(2)contents in the environment of proton exchange mem...In this study,the corrosion resistance and the stability of passive films on the laser melting depositionprocessed 316L austenitic stainless steel with varying CeO_(2)contents in the environment of proton exchange membrane fuel cells were investigated using a combination of electrochemical and microstructural analyses.The findings reveal that 316L austenitic stainless steel with 0.20 wt%CeO_(2)exhibits a superior corrosion resistance,primarily due to grain refinement,a high proportion of low-angle grain boundaries and low∑coincidence site lattice grain boundaries,as well as increased dislocation density.The addition of CeO_(2)optimizes the type and size of inclusions and exerts a drag effect on grain boundaries,promoting the refinement of grains in the laser melting deposition-processed 316L auste nitic stainless steel.Moreover,the combined effect of these factors provides more active sites for the formation of a dense passive film with fewer point defects.展开更多
Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates...This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2) reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2) is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2) substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.展开更多
A new combination method consisting of ball milling, carbothermic reduction and hydrochloric acid leaching was proposed for the preparation of nanosized synthetic rutile from natural ilmenite. The ball milling was emp...A new combination method consisting of ball milling, carbothermic reduction and hydrochloric acid leaching was proposed for the preparation of nanosized synthetic rutile from natural ilmenite. The ball milling was employed to grind ilmenite into small particles. The carbothermic reduction was carried out to yield a high titanium slag, which would be easily purified by subsequent leaching procedure. Factors affecting the hydrochloric acid process, namely the leaching time, temperature, and acid concentration, were studied. After leaching and calcining the milled and annealed mixture of FeTiO3/C under the optimal conditions, the TiO2 nanoparticles with size of 10-200 nm and purity〉98.0% were obtained.展开更多
Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive a...Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive ascorbic acid (AA) in air at room temperature, which was an interesting phenomenon. The features of the two kinds of NPs were characterized by XRD, TEM and extinction spectra. Cu2O@Cu NPs with different shell thicknesses showed wide tunable optical properties for the localized surface plasmon (LSP) in metallic Cu. But Cu2O@Cu2O NPs did not indicate this feature. FTIR results reveal that Cu+ ions on the surface of Cu2O shell coordinate with N and O atoms in PVP and are further reduced to metallic Cu by excessive AA and then form a nucleation site on the surface of Cu2O nanocrystalline. PVP binds onto different sites to proceed with the reduction utill all the Cu sources in Cu2O shell are completely assumed.展开更多
SnO2 nanoparticles with the average particle size of 5-30 nm were synthesized using SnCl4·5H2O as the precursor and NH3·H2O as the mineralizing agent by hydrothermal method.In the case of 1 kg/batch producti...SnO2 nanoparticles with the average particle size of 5-30 nm were synthesized using SnCl4·5H2O as the precursor and NH3·H2O as the mineralizing agent by hydrothermal method.In the case of 1 kg/batch production,the effects of synthesis conditions including solution concentration,reaction temperature,pressure,time and pH value on the grain size,particle morphology and crystal structure of SnO2 were systematically studied.The particles were characterized by X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The results show that,the particle size can be well controlled in the range of 5-30 nm by adjusting the processing parameters such as reaction temperature and time when the crystal structure and particle morphology remain unchanged.The previous reports,the unusual dependences of the grain size of SnO2 on reaction temperature and time were found.The mechanism for such abnormal grain growth behavior was tentatively elucidated.展开更多
The function of protein in long-range biological electron transfer is a question of debate. We report some preliminary results in femtosecond spectroscopic study of photosynthetic bacterial light-harvesting antenna co...The function of protein in long-range biological electron transfer is a question of debate. We report some preliminary results in femtosecond spectroscopic study of photosynthetic bacterial light-harvesting antenna complex assembled onto TiO2 nanoparticle with an average size of 8 nm in diameter. Crystal structure shows that photosynthetic bacterial antenna complex LH2 has a ring-like structure composed by alpha- and beta-apoprotein helices. The alpha- and beta-transmembrance helices construct two concentric cylinders with pigments bacteriochlorophyll a (Bchl a) and carotenoid (Car) buried inside the protein. We attempt to insert TiO2 nanoparticle into the cavity of the inner cylindrical hollow of LH2 to investigate the nature of the electron transfer between the excited-state Bchl a and the TiO2 nanoparticle. A significant decrease in the ground state bleaching recovery time constant for Bchl a at 850 run (B850) in respect to that of the Bchl a in free LH2 has been observed. By using the relation of distance-dependent long-range electron transfer rate in protein, the distance between the donor B850 and the acceptor TiO2 nanoparticle has been estimated, which is about 0.6 nm. The proposed method of assembling proteins onto wide-gap semiconductor nanoparticle can be a promising way to determine the role of the protein playing in biological electron transfer processes.展开更多
Nanoparticles have been widely applied in diagnosis and therapy due to the high loading of insoluble drug, increased target accumulation and interaction with biological tissues. Recently, severe side effects of nanopa...Nanoparticles have been widely applied in diagnosis and therapy due to the high loading of insoluble drug, increased target accumulation and interaction with biological tissues. Recently, severe side effects of nanoparticles have been reported, but the underlying mechanism remains largely unknown. In our study, we aim to understand the safety of paclitaxel （PTX） loaded bovine albumin nanoparticles （BNPs） and active targeted PTX loaded BNPs to normal vital organ or tissue in vivo. The anti-human epidermal growth factor receptor 2 （HER2/neu） peptide mimetic （AHNP） was covalent bound to surface of BNPs （AHNP-BNPs） to exert selected delivery to HER2＋ cells. In HER2＋ tumor xenographs, saline （control）, PTX traditional formula （medium of Cremophor EL-ethanol）, BNPs, and AHNP-BNPs were administrated to evaluate the toxicity. There is no severe neutropenia or anemia with treatment of BNPs and AHNP-BNPs compared with traditional PTX injection. We also evaluated their damage on normal organs, including liver, kidney, spleen, lung and heart to fully estimate the safety of AHNP-BNPs and BNPs delivery systems. We observed similar toxicity in liver and lung in mice treated with BNPs or PTX injection, but decreased liver damage in mice treated with AHNP-BNPs. Further studies are rcouired to confirm our conclusion.展开更多
Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emissi...Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the crystalline structure, chemical valence states and morphology of TiO2 nanoparticles. UV-Vis absorption spectrum was used to measure the optical absorption property of the samples. The photocatalytic performance of the samples was characterized by degrading 20 mg/L methyl orange under UV-Vis irradiation. The results show that the Cu-doped TiO2 nanoparticles exhibit a significant increase in photocatalytic performance over the pure TiO2 nanoparticles, and the TiO2 nanoparticles doped with 1.0% Cu show the best photocatalytic performance. The improvement in photocatalytic performance is attributed to the enhanced light adsorption in UV-Vis range and the decrease of the recombination rate of photoinduced electron-hole oair of the Cu-doped TiO2 nanoparticles.展开更多
Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles （TiO2-NPs...Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles （TiO2-NPs）, but there are limited data on ecotoxicity to aquatic organisms. In this work, the sub-acute toxicity of TiO2-NPs to carp （Cyprinus carpio） was assessed. Superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） activities and lipid peroxidation （LPO） levels in liver, gill and brain tissues of carps varied with concentration of TiO2-NPs suspensions and exposure time （up to 8 d）. As a result, 100 and 200 mg/L TiO2-NPs caused statistically significant decrease in SOD, CAT and POD activities and significant increase in LPO levels in tissues （P 〈 0.05）, suggesting that the fish exposed to these two concentrations of TiO2-NPs suffered from the oxidative stress. The extent of depletion of antioxidant enzymes activities and the elevation of LPO in the liver was the greatest, indicating that the liver might be the most susceptible organ to TiO2-NPs exposure. In addition, carps had gill pathologies including edema and thickening of gill lamellae as well as gill filaments, and liver pathologies including necrotic and apoptosis hepatocytes after exposed to 100 and 200 mg/L TiO2-NPs for 20 d. These results indicated a potential risk from TiO2-NPs released into the aqueous environment.展开更多
An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel-Michael addition of aromatic aldehydes,methylcyanoacetate and 4（6）-aminouracil in solvent-free conditio...An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel-Michael addition of aromatic aldehydes,methylcyanoacetate and 4（6）-aminouracil in solvent-free conditions in the presence of 10 mol%of ZrO_2 nanoparticles（ZrO_2 NPs） as a heterogenous catalyst.The procedure is formed in high yields,short reaction time and an environmentally friendly specificity.展开更多
Nano-Al2O3 particles modified Ag Cu Ni filler was adopted to braze the SiO2 ceramic and TC4.The effects of filler size as well as the brazing temperature on the interfacial microstructure and mechanical property of th...Nano-Al2O3 particles modified Ag Cu Ni filler was adopted to braze the SiO2 ceramic and TC4.The effects of filler size as well as the brazing temperature on the interfacial microstructure and mechanical property of the joints were investigated.Nanoscale filler reduced the phases dimension and promoted the homogeneous distribution of microstructure,obtaining a higher joint strength when compared to microscale filler.The increase of brazing temperature made the accelerating dissolution and diffusion of Ti,which promoted the increase of thickness of Ti4O7+TiSi2 layer adjacent to SiO2 ceramic and diffusion layer zone nearby TC4 alloy.The hypoeutectic structure was produced in the brazing seam due to the high Ti content.The maximum shear strength of^40 MPa was obtained at 950°C for 10 min.展开更多
A low cost spin coating route of fabricating CuInS2 polycrystalline thin films by reactive sintering method was put forward. The ink for spin coating was optimized by pre-reducing the precursor powders in hydrogen, wh...A low cost spin coating route of fabricating CuInS2 polycrystalline thin films by reactive sintering method was put forward. The ink for spin coating was optimized by pre-reducing the precursor powders in hydrogen, which turned the nanoparticle precursor powders from mixed sulfides into a mixture of CuInS2 and Cu-In metal alloys. The results of scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra showed that this optimization could highly improve the performance of CuInS2 polycrystalline thin films, including higher packing density, less impurity phases, and better quality. The energy gap of optimized CuInS2 thin film was determined to be about 1.45 eV by absorption spectroscopy measurement.展开更多
AIM: To investigate the anti-tumor effect and mechanisms of magnetic nanoparticles targeting hepatocellular carcinoma. METHODS: Human hepatocellular carcinoma was induced in nude mice, and the mice were randomly divid...AIM: To investigate the anti-tumor effect and mechanisms of magnetic nanoparticles targeting hepatocellular carcinoma. METHODS: Human hepatocellular carcinoma was induced in nude mice, and the mice were randomly divided into group A receiving normal saline, group B receiving magnetic nanoparticles containing 5-fluorouracil (5-FU), group C receiving 5-FU, and group D receiving magnetic nanoparticles containing 5-FU with a magnetic field built in tumor tissues. The tumor volume was measured on the day before treatment and 1, 4, 7, 10 and 13 d after treatment. Tumor tissues were isolated for examination of the expression of bcl-2, bax and caspase 3 by immunohistochemical method, reverse transcription polymerase chain reaction and Western blotting. RESULTS: The tumor volume was markedly lower in groups C and D than in groups A and B (group C or D vs group A or B, P < 0.01). The volume was markedly lower in group D than in group C (P < 0.05). The expression of protein and mRNA of bcl-2 was markedly lower in groups C and D than in groups A and B (group C or D vs group A or B, P < 0.01), and was markedly lower in group D than in group C (P < 0.01). The expression of bax and caspase 3 in groups C and D was signif icantly increased, compared with that in groups A and B (P < 0.01). CONCLUSION: The targeted magnetic nanoparticles containing 5-FU can improve the chemotherapeutic effect of 5-FU against hepatocellular carcinoma by decreasing the expression of bcl-2 gene, and increasing the expression of bax and caspase 3 genes.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFA1500401)National Natural Science Foundation of China(NSFC,Nos.21821003,22371304+3 种基金223B2123)Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(No.24lgzy006)Science and Technology Innovation Special Support Project of Guangdong Province,China(No.STKJ2023078)the Guangzhou Science and Technology Program(No.SL2023A04J01767)。
文摘The efficient production of acetate through electrochemical CO_(2)reduction reaction(eCO_(2)RR)with low energy consumption has consistently been a challenging yet extremely significant task.Current catalysts suffered from high energy consumption and low relative purity of acetate product.Herein,we report ultrasmall Cu_(2)O nanoparticles with an average size of 2.5±0.09 nm immobilized on a conductive copper-based metal-organic framework(Cu-THQ)(denoted as Cu_(2)O@Cu-THQ),which attained a Faradaic efficiency of 65(3)%for acetate at a very low potential of-0.3 V vs.RHE with a current density of 10.5 m A/cm^(2).Importantly,as there are no other liquid phase products such as formate,methanol or ethanol,the relative purity of the obtained acetate product was as high as 100%.Taking into account the relative purity of the liquid product,current density,and energy consumption,the performance for electroreduction of CO_(2)to acetate of Cu_(2)O@Cu-THQ is not only much higher than that of the commercial Cu_(2)O nanoparticles,but also higher than those of all reported catalysts.Operando infrared spectroscopy and theoretical calculations indicated that the synergy effect between Cu-THQ and Cu_(2)O promoted the e CO_(2)RR to yield acetate.Specifically,the hydroxyl group on the organic ligand THQ in the Cu-THQ formed hydrogen bond interactions with the key C_(2)intermediates(*CH_(2)COOH and*HOCCOH)adsorbed on Cu_(2)O,which played a crucial role in stabilizing the key C_(2)intermediates and thus reduced the formation energy of the key C_(2) intermediates.
文摘In this paper,polyamide(PA)woven fabric was used as the base fabric,and polyurethane(PU)solution containing silica nanoparticles(PU@SiO_(2)NPs)was used as the coating solution to prepare composite tent fabric(PA/PU@SiO_(2)).The morphology,structure,and durability of the tent fabric under ultraviolet(UV)radiation,waterstained,or thermal conditions were investigated.The results show that compared with PA/PU fabric without SiO_(2)NPs,when the mass fraction of SiO_(2)NPs in PU coating is 5%,the air permeability of PA/PU@SiO_(2)fabric decreases from about 7.5 to 6.0 nm/s,while the reflectivity to UVvisible light is significantly improved.The surface wettability decreases,as indicated by the average water contact angle(WCA)on PA/PU@SiO_(2)remaining stable at 47°after 9 min.After thermal treatment,the PA/PU@SiO_(2)fabric shows superior mechanical stability.The degradation rate of the tensile strength is only 6.3%,approximately half that of the PA/PU fabric.Meanwhile,the elongation at break increases to 98.9%,compared to 61.8%for the PA/PU fabric.
基金financially supported by the National Key R&D Program of China(No.2021YFB 3802400)the National Natural Science Foundation of China(Nos.U2130208,22279020 and 52301264)the Science and Technology Commission of Shanghai Municipality(Nos.23ZR1406500 and 22ZR1406500)
文摘As a typical reactive composite hydrogen storage system,2LiBH_(4)-MgH_(2)holds an ultrahigh hydrogen storage capacity of 11.5 wt%.However,it suffers from sluggish hydrogen storage kinetics due to the difficult nucleation of MgB_(2).Herein,amorphous VB_(2)nanoparticles with an average size of approximately 32 nm are synthesized to enhance the hydrogen storage performance of 2LiBH_(4)-MgH_(2)composite.VB_(2),sharing the same hexagonal structure with MgB_(2)with a d-value mismatch ratio of only 2.28%,could serve as effective nucleation sites for promoting the formation of MgB_(2).Theoretical calculations reveal that the introduction of VB_(2)significantly reduces the binding energies of B and Mg,facilitating in situ nucleation of MgB_(2).As a result,after the introduction of VB_(2)nanoparticles,complete hydrogen desorption of 9.23 wt%is achieved for 2LiBH_(4)-MgH_(2)within 2 h at 400℃,which is 4 times shorter than the time required for pure 2LiBH_(4)-MgH_(2),and no nucleation incubation period for hydrogen desorption is observed even at a low temperature of380℃.More importantly,a reversible capacity of9.3 wt%,corresponding to a capacity retention of 100%,could be preserved after 10 cycles of hydrogen storage,demonstrating stable reversible hydrogen storage performance.This study provides a novel technological pathway for improving the reversible hydrogen storage performance of composite metal hydrides and offers significant insights into the development of high-performance hydrogen storage materials.
基金supported by the Inner Mongolia Natural Science Foundation(2024QN02011)basic scientific research business expense project of colleges and universities directly under Inner Mongolia(2023QNJS131 and 2024QNJS127)Science and Technology Plan Program of Inner Mongolia Autonomous Region(2023YFDZ0031).
文摘Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and structural evaluation utilized XRD,TEM,Raman,FTIR and BET techniques.Cu/TiO_(2)showed rich defects and a higher specific surface area than that of TiO_(2).The 1Cu/TiO_(2)(molar ratio Cu/TiO_(2)of 1/100)showed the best performance to adsorption of CR solution at different reaction conditions(contact duration,CR concentration,adsorbent dose,temperature,and initial pH).Adsorption kinetics and equilibrium isotherms were well-described with a pseudo-second-order kinetics and Freundlich model,respectively.The negative ΔG indicates stable adsorption of CR on the Cu/TiO_(2)surface.The adsorption efficiency only decreases by 6%after 5 cycles of adsorption regeneration.The successful synthesis of Cu/TiO_(2)offers a new possibility to address the problems related to CR dye from aqueous solutions.
文摘The p-block metal(In,Sn,Bi,etc.)-based electrocatalysts have exhibited excellent activity in the electrocatalytic CO_(2)reduction(ECR)to formate.However,the rapid decrease in catalytic activity caused by catalyst reconstruction and agglomeration under ECR conditions significantly restricts their practical applications.Herein,we developed a sulfur anchoring strategy to stabilize the high-density sub-3 nm In_(2)S_(3)nanoparticles on sulfur-doped porous carbon substrates(i-In_(2)S_(3)/S-C)for formate production.Systematic characterizations evidenced that the as-prepared catalyst exhibited a strong metal sulfide-support interaction(MSSI),which effectively regulated the electronic states of In_(2)S_(3),achieving a high formate Faradaic efficiency of 91%at−0.95 V vs.RHE.More importantly,the sulfur anchoring effectively immobilized the sub-3 nm In_(2)S_(3)nanoparticles to prevent them from agglomeration.It enabled the catalysts to exhibit much higher durability than the In_(2)S_(3)samples without sulfur anchoring,demonstrating that the strong MSSI and fast charge transfer on the catalytic interface could significantly promote the structural stability of In_(2)S_(3)catalysts.These results provide a viable approach for developing efficient and stable electrocatalysts for CO_(2)reduction.
基金Project supported by National Natural Science Foundation of China(52071227)Central Government Guidance to Local Science and Technology Development(YDZJSK20231A046)Key Scientific Research Project in Shanxi Province(202102050201003,202102050201010)。
文摘In this study,the corrosion resistance and the stability of passive films on the laser melting depositionprocessed 316L austenitic stainless steel with varying CeO_(2)contents in the environment of proton exchange membrane fuel cells were investigated using a combination of electrochemical and microstructural analyses.The findings reveal that 316L austenitic stainless steel with 0.20 wt%CeO_(2)exhibits a superior corrosion resistance,primarily due to grain refinement,a high proportion of low-angle grain boundaries and low∑coincidence site lattice grain boundaries,as well as increased dislocation density.The addition of CeO_(2)optimizes the type and size of inclusions and exerts a drag effect on grain boundaries,promoting the refinement of grains in the laser melting deposition-processed 316L auste nitic stainless steel.Moreover,the combined effect of these factors provides more active sites for the formation of a dense passive film with fewer point defects.
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金The authors thank,DST-FIST,Government of India for fund-ing toward infrastructure and instrumentation facilities at ACIC,St.Joseph’s College(Autonomous),Tiruchirappalli-620002,India.
文摘This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2) reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2) is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2) substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.
基金Project (2007CB613601) supported by the National Basic Research Program of ChinaProject supported by the Postdoctoral Science Foundation of Central South University, China
文摘A new combination method consisting of ball milling, carbothermic reduction and hydrochloric acid leaching was proposed for the preparation of nanosized synthetic rutile from natural ilmenite. The ball milling was employed to grind ilmenite into small particles. The carbothermic reduction was carried out to yield a high titanium slag, which would be easily purified by subsequent leaching procedure. Factors affecting the hydrochloric acid process, namely the leaching time, temperature, and acid concentration, were studied. After leaching and calcining the milled and annealed mixture of FeTiO3/C under the optimal conditions, the TiO2 nanoparticles with size of 10-200 nm and purity〉98.0% were obtained.
基金Projects(41172110,61107090)supported by the National Natural Science Foundation of China
文摘Cu2O@Cu2O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu2O@Cu2O NPs were easily converted to Cu2O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive ascorbic acid (AA) in air at room temperature, which was an interesting phenomenon. The features of the two kinds of NPs were characterized by XRD, TEM and extinction spectra. Cu2O@Cu NPs with different shell thicknesses showed wide tunable optical properties for the localized surface plasmon (LSP) in metallic Cu. But Cu2O@Cu2O NPs did not indicate this feature. FTIR results reveal that Cu+ ions on the surface of Cu2O shell coordinate with N and O atoms in PVP and are further reduced to metallic Cu by excessive AA and then form a nucleation site on the surface of Cu2O nanocrystalline. PVP binds onto different sites to proceed with the reduction utill all the Cu sources in Cu2O shell are completely assumed.
基金Project(2006AA03Z413) supported by the Hi-tech Research and Development Program of China
文摘SnO2 nanoparticles with the average particle size of 5-30 nm were synthesized using SnCl4·5H2O as the precursor and NH3·H2O as the mineralizing agent by hydrothermal method.In the case of 1 kg/batch production,the effects of synthesis conditions including solution concentration,reaction temperature,pressure,time and pH value on the grain size,particle morphology and crystal structure of SnO2 were systematically studied.The particles were characterized by X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The results show that,the particle size can be well controlled in the range of 5-30 nm by adjusting the processing parameters such as reaction temperature and time when the crystal structure and particle morphology remain unchanged.The previous reports,the unusual dependences of the grain size of SnO2 on reaction temperature and time were found.The mechanism for such abnormal grain growth behavior was tentatively elucidated.
文摘The function of protein in long-range biological electron transfer is a question of debate. We report some preliminary results in femtosecond spectroscopic study of photosynthetic bacterial light-harvesting antenna complex assembled onto TiO2 nanoparticle with an average size of 8 nm in diameter. Crystal structure shows that photosynthetic bacterial antenna complex LH2 has a ring-like structure composed by alpha- and beta-apoprotein helices. The alpha- and beta-transmembrance helices construct two concentric cylinders with pigments bacteriochlorophyll a (Bchl a) and carotenoid (Car) buried inside the protein. We attempt to insert TiO2 nanoparticle into the cavity of the inner cylindrical hollow of LH2 to investigate the nature of the electron transfer between the excited-state Bchl a and the TiO2 nanoparticle. A significant decrease in the ground state bleaching recovery time constant for Bchl a at 850 run (B850) in respect to that of the Bchl a in free LH2 has been observed. By using the relation of distance-dependent long-range electron transfer rate in protein, the distance between the donor B850 and the acceptor TiO2 nanoparticle has been estimated, which is about 0.6 nm. The proposed method of assembling proteins onto wide-gap semiconductor nanoparticle can be a promising way to determine the role of the protein playing in biological electron transfer processes.
基金the National Natural Science Foundation of China(Grant No.30970785,81273454)Beijing Natural Science Foundation(Grant No.7132113)+2 种基金National Basic Research Program(Grant No.2009CB930303,2013CB932501)Doctoral Foundation of the Ministry of Education(Grant No.20100001110056)Innovation Team of Ministry of Education(Grant No.BMU20110263)
文摘Nanoparticles have been widely applied in diagnosis and therapy due to the high loading of insoluble drug, increased target accumulation and interaction with biological tissues. Recently, severe side effects of nanoparticles have been reported, but the underlying mechanism remains largely unknown. In our study, we aim to understand the safety of paclitaxel （PTX） loaded bovine albumin nanoparticles （BNPs） and active targeted PTX loaded BNPs to normal vital organ or tissue in vivo. The anti-human epidermal growth factor receptor 2 （HER2/neu） peptide mimetic （AHNP） was covalent bound to surface of BNPs （AHNP-BNPs） to exert selected delivery to HER2＋ cells. In HER2＋ tumor xenographs, saline （control）, PTX traditional formula （medium of Cremophor EL-ethanol）, BNPs, and AHNP-BNPs were administrated to evaluate the toxicity. There is no severe neutropenia or anemia with treatment of BNPs and AHNP-BNPs compared with traditional PTX injection. We also evaluated their damage on normal organs, including liver, kidney, spleen, lung and heart to fully estimate the safety of AHNP-BNPs and BNPs delivery systems. We observed similar toxicity in liver and lung in mice treated with BNPs or PTX injection, but decreased liver damage in mice treated with AHNP-BNPs. Further studies are rcouired to confirm our conclusion.
基金Project(2010CB631001)supported by the National Basic Research Program of ChinaProject(50871046)supported by the National Natural Science Foundation of China
文摘Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the crystalline structure, chemical valence states and morphology of TiO2 nanoparticles. UV-Vis absorption spectrum was used to measure the optical absorption property of the samples. The photocatalytic performance of the samples was characterized by degrading 20 mg/L methyl orange under UV-Vis irradiation. The results show that the Cu-doped TiO2 nanoparticles exhibit a significant increase in photocatalytic performance over the pure TiO2 nanoparticles, and the TiO2 nanoparticles doped with 1.0% Cu show the best photocatalytic performance. The improvement in photocatalytic performance is attributed to the enhanced light adsorption in UV-Vis range and the decrease of the recombination rate of photoinduced electron-hole oair of the Cu-doped TiO2 nanoparticles.
基金supported by the China Postdoctoral Science Foundation Funded Project (No 20080431217)the Cheung Kong Scholar Program of Education Ministry of China
文摘Increasing application of nanotechnology highlights the need to clarify and understand nanotoxicity. Mammalian and in vitro studies have raised concerns about the toxicity of titanium dioxide nanoparticles （TiO2-NPs）, but there are limited data on ecotoxicity to aquatic organisms. In this work, the sub-acute toxicity of TiO2-NPs to carp （Cyprinus carpio） was assessed. Superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） activities and lipid peroxidation （LPO） levels in liver, gill and brain tissues of carps varied with concentration of TiO2-NPs suspensions and exposure time （up to 8 d）. As a result, 100 and 200 mg/L TiO2-NPs caused statistically significant decrease in SOD, CAT and POD activities and significant increase in LPO levels in tissues （P 〈 0.05）, suggesting that the fish exposed to these two concentrations of TiO2-NPs suffered from the oxidative stress. The extent of depletion of antioxidant enzymes activities and the elevation of LPO in the liver was the greatest, indicating that the liver might be the most susceptible organ to TiO2-NPs exposure. In addition, carps had gill pathologies including edema and thickening of gill lamellae as well as gill filaments, and liver pathologies including necrotic and apoptosis hepatocytes after exposed to 100 and 200 mg/L TiO2-NPs for 20 d. These results indicated a potential risk from TiO2-NPs released into the aqueous environment.
文摘An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel-Michael addition of aromatic aldehydes,methylcyanoacetate and 4（6）-aminouracil in solvent-free conditions in the presence of 10 mol%of ZrO_2 nanoparticles（ZrO_2 NPs） as a heterogenous catalyst.The procedure is formed in high yields,short reaction time and an environmentally friendly specificity.
基金supported by National Natural Science Foundation of China(Grant Nos.51505105,51875130 and 51775138)the Key Research&Development Program of Shandong Province(No.2017GGX40103).
文摘Nano-Al2O3 particles modified Ag Cu Ni filler was adopted to braze the SiO2 ceramic and TC4.The effects of filler size as well as the brazing temperature on the interfacial microstructure and mechanical property of the joints were investigated.Nanoscale filler reduced the phases dimension and promoted the homogeneous distribution of microstructure,obtaining a higher joint strength when compared to microscale filler.The increase of brazing temperature made the accelerating dissolution and diffusion of Ti,which promoted the increase of thickness of Ti4O7+TiSi2 layer adjacent to SiO2 ceramic and diffusion layer zone nearby TC4 alloy.The hypoeutectic structure was produced in the brazing seam due to the high Ti content.The maximum shear strength of^40 MPa was obtained at 950°C for 10 min.
文摘A low cost spin coating route of fabricating CuInS2 polycrystalline thin films by reactive sintering method was put forward. The ink for spin coating was optimized by pre-reducing the precursor powders in hydrogen, which turned the nanoparticle precursor powders from mixed sulfides into a mixture of CuInS2 and Cu-In metal alloys. The results of scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra showed that this optimization could highly improve the performance of CuInS2 polycrystalline thin films, including higher packing density, less impurity phases, and better quality. The energy gap of optimized CuInS2 thin film was determined to be about 1.45 eV by absorption spectroscopy measurement.
基金Supported by the Hi-Tech Research and Development Program of China, NO.2002AA214061
文摘AIM: To investigate the anti-tumor effect and mechanisms of magnetic nanoparticles targeting hepatocellular carcinoma. METHODS: Human hepatocellular carcinoma was induced in nude mice, and the mice were randomly divided into group A receiving normal saline, group B receiving magnetic nanoparticles containing 5-fluorouracil (5-FU), group C receiving 5-FU, and group D receiving magnetic nanoparticles containing 5-FU with a magnetic field built in tumor tissues. The tumor volume was measured on the day before treatment and 1, 4, 7, 10 and 13 d after treatment. Tumor tissues were isolated for examination of the expression of bcl-2, bax and caspase 3 by immunohistochemical method, reverse transcription polymerase chain reaction and Western blotting. RESULTS: The tumor volume was markedly lower in groups C and D than in groups A and B (group C or D vs group A or B, P < 0.01). The volume was markedly lower in group D than in group C (P < 0.05). The expression of protein and mRNA of bcl-2 was markedly lower in groups C and D than in groups A and B (group C or D vs group A or B, P < 0.01), and was markedly lower in group D than in group C (P < 0.01). The expression of bax and caspase 3 in groups C and D was signif icantly increased, compared with that in groups A and B (P < 0.01). CONCLUSION: The targeted magnetic nanoparticles containing 5-FU can improve the chemotherapeutic effect of 5-FU against hepatocellular carcinoma by decreasing the expression of bcl-2 gene, and increasing the expression of bax and caspase 3 genes.
