Issn: CN 22-1128/O6
CN:ISSN 1000-0518
Director:Chinese Academy of Sciences
Host:Changchun Institute of Applied Chemistry, Chinese Academy of Sciences
Aluminum porphyrin is a soil-tolerant metal porphyrin complex. Although its catalytic activity on the copolymerization of CO2 and propylene oxide has been disclosed by Inoue in 1978, the catalytic activity is still very low, and the synthesized poly(propylene carbonate) has low relative molecular mass. It is a big challenge to make progress on the catalytic performance of aluminum porphyrin. In this work, the electronic environment of central aluminum was adjusted by delicate design of porphyrin ligand using meso-tetrasubstituted porphyrin derivatives that were employed to catalyze the copolymerization of CO2 and propylene oxide with bis-(triphenyl phosphine) iminium chloride(PPNCl) as the co-catalyst. It was found that the electronic environment of the central aluminum ion had great effect on the catalytic performance of aluminum porphyrin catalysts, the turnover frequency(TOF) value of Cl substituted aluminum porphyrin catalyst 6a reached 2672 h-1 at 90 ℃ and 3 MPa, while poly(propylene carbonate) with relative molecular mass of 1.84×104 was afforded using catalyst 4b bearing toluene sulfonic group(OTs-) as axial group of good leaving ability. Our work indicates that delicate designed aluminum porphyrin can become a possible candidate as high performance catalyst in the copolymerization of CO2 and propylene oxide, under optimized copolymerization conditions.
Highly efficient and polychromatic luminescent CsPbX3 perovskite quantum dots(PQDs) were synthesized under room temperature. The entire reaction is very fast and simple. Polychromatic luminescence of CsPbX3 PQDs can be achieved by adjusting different halide compositions(Cl, Br, I). The as-prepared CsPbX3 PQDs have a cubic morphology with an average size about 10 nm. The photoluminescence of CsPbX3 PQDs has a characteristic of wide visible spectral region of 410~630 nm, narrow emission line-widths of 14~38 nm and quantum yields of 10%~90%. Finally, the CsPbX3 PQDs are successfully applied to prepare light emitting diode(LED) devices. At a constant voltage work for a long time, the emission color, intensity, and color coordinates of the LED device remain unchanged.
The phosphinothricin acetyltransferase(PAT) gene is a kind of exogenous DNA segments indicating genetically modified plants. In this research, a sensitive method for determination of the PAT gene in transgenic maize has been developed using reduced graphene oxide and nano zirconia(nanoZrO2) composites as a platform for immobilizing DNA probes. First, the graphene oxide was direct electrochemically reduced on a glassy carbon electrode(GCE); then, a layer of nanoZrO2 was covered on the modified electrode. Last, the DNA probes were immobilized via the affinity between phosphate groups in the DNA probes and the oxygen in nanoZrO2. The hybridization of the DNA probes with the PAT gene segments was monitored by differential pulse voltammetry(DPV). The sensor was stable, reproducible and sensitive to effectively discriminate the PAT gene in transgenic maize. The detection limit was 2.0×10-15 mol/L.
A novel and efficient protocol towards (E)-β-vinyl sulfone derivatives by tetrabutylammonium Iodide(TBAI)/K2S2O8 mediated denitrative sulfonylation of readily prepared β-nitrostyrenes and economical sulfonylhydrazides was described. The corresponding (E)-β-vinyl sulfone compounds were obtained in moderate to good yields. Compared with reported methods, the present strategy features metal-free, acid and base-free.
A micro-luteolin carbon fiber acidity microelectrode(Lu/CFME) was made with luteolin as a pH sensitive substance, carbon fiber as conductive matrix and solid paraffin as a binder. An all solid state acidity microelectrode set was combinated by Lu/CFME as working electrode, a self-made conductive gel type all-solid micro Ag/AgCl as reference electrode and a platinum wire microelectrode as auxiliary electrode. The response of the electrode set to the effective acidity was studied in the solution of phosphate buffer solution at pH 2.00~10.00 by cyclic voltammetry. The results show that there is a pair of reversible redox peaks on the cyclic voltammetry curve. Their peak potentials(Epa) were all linear with pH. Based on this, a method for determining the acidity of solution was established by square wave voltammetry, and the linear regression equation for peak potential of oxidation peak and pH is Epa(V)=-0.0567pH+0.603(r=0.999). The electrode set is micro, non-toxic and anti-interference. It is applied to acidity measurement of trace saliva and sweat on the skin surface, and satisfactory results have been obtained. Therefore, this result provides a technical basis for real-time, in-vivo detection of body fluids.
Chitosan oligosaccharide thiosemicarbazide was prepared in one-pot. Then chitosan oligosaccharide thiosemicarbazone was synthesized by the reaction of chitosan thiosemicarbazide with 2-pyridinecarboxaldehyde. Chitosan oligosaccharide thiosemicarbazone Cu(Ⅱ) complex was thus obtained by the reaction of chitosan thiosemicarbazide with Cu(Ⅱ) salt. The structure of the synthesized compounds was characterized by infrared(IR) spectroscopy, ultraviolet-visible(UV-Vis) spectroscopy, nuclear magnetic resonance(NMR), inductively coupled plasma(ICP), and thermogravimetry-differential thermal analysis(TG-DTA). The antifungal behaviors of chitosan oligosaccharide and its derivatives against three crop-threatening pathogenic fungi:Phytophthora capsici(P.capsici), Phytophthora nicotianae(P.nicotianae), Fusarium graminearum(F.graminearum) were investigated by mycelial growth rate method in vitro. The results show that the inhibitory index of chitosan thiosemicarbazone Cu(Ⅱ) complex against P.capsici, P.nicotianae, F.graminearum is 74.19%, 56.60%, 66.60%, respectively, and is higher than those observed with chitosan.
The dissolution of calix[4]quinone(C4Q) in electrolytes can be inhibited by the C4Q/CMK-3(mesoporous carbon) nanocomposites prepared through perfusion method, but the electrochemical performance of the nanocomposites needs to be further improved. We prepared a serious of C4Q/CMK-3/SWCNTs(single-walled carbon nanotubes) composites with different ratio by deaerating-stirring method. In these composites, SWCNTs substituted conductive carbon blacks Super-P of the original C4Q/CMK-3 composites, which also reduced the content of CMK-3. SEM and electrochemical tests are conducted to investigate the relation of the morphology and electrochemical performance that cased by SWCNTs. The results show that the optimum mass ratio was m(C4Q):m(CMK-3):m(SWCNTs)=(1:1:1), which shows a capacity retention of 55% after 100 cycles at 0.1 C. Even at 1 C, the discharge capacity is still 260 mA·h/g. The significant improvement in the electrochemical performance could be ascribed to the formation of three-dimensional conductive network by SWCNTs.
Two ferrocene-based isomeric chalcone derivatives 1-ferrocenly-3-(thiophen-2-yl) prop-2-en-1-one(a) and 1-(ferrocenly)-3-(thiophen-3-yl) prop-2-en-1-one(b) were synthesized. Their third-order nonlinear optical properties were measured by Z-scan technique with ultrafast laser operating at 532 nm laser in 180 fs pulse, respectively. The relevant parameters were given as follows: the nonlinear absorption coefficient β=-2.1×10-12 m/W, the nonlinear refractive index n2=1.9×10-19 m2/W and the third-order nonlinear hyperpolarizability γ=5.37×10-32 esu for compound a; β=-1.2×10-13 m/W, n2=2.0×10-19 m2/W and γ=4.48×10-32 esu for compound b. The results indicate that the excitation of femtosecond laser enables intramolecular charge transfer to occur quickly. Thus two compounds can exhibit ultrafast third-order nonlinear optical response. The orbital energies, polarizabilities and possession ratios of different groups in frontier molecular orbitals of compounds a and b were calculated by B3LYP/6-311+G(d,p) level. The percentage of ferrocene group in the frontier molecular orbitals of compounds a and b is 97% and 98%, respectively, which indicates that ferrocene group plays a leading role in the nonlinear optical properties of two compounds.
Attapulgite clay(ATP) supported nano TiO2-Fe3O4(TiO2-Fe3O4-ATP) adsorbents were prepared by sol-gel method in one-pot, and its adsorption and desorption properties of Cr(Ⅵ) in simulated wastewater were studied. The structure and contents of the adsorbent were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectrometer(FT-IR) and EDS before and after nano TiO2-Fe3O4 loading, The effects of the ratio of reactants, adsorption time, pH value, temperature, dosage and initial concentration on the adsorption rate of Cr(Ⅵ) were studied. The best performance of the adsorbents was observed when the molar fraction of Ti in the total loading is 75%. The attapulgite adsorbent loaded with nano TiO2 and Fe3O4 has better adsorption effect on the removal of Cr(Ⅵ) when the mass of adsorbent is 0.6 g. When the initial concentration of Cr(Ⅵ) is less than 0.8 mg/L and the pH value is 6 at 20 ℃, the adsorption rate of Cr(Ⅵ) reached 79.8%. The adsorption of Cr(Ⅵ) by TiO2-Fe3O4-ATP can be described by Freundlich equation. At 20~40 ℃, the free energy(ΔG), enthalpy(ΔH) and entropy(ΔS) changes of the adsorption process were calculated. The results show that ΔG<0, ΔS=-43.55 J/(mol·K), ΔH=-14.36 kJ/mol, indicating that the adsorption is spontaneous, exothermic and entropy reduction. Pseudo-first-order kinetic model, pseudo-second-order kinetic model and shell progressive model were studied for the kinetic data. The result shows that the adsorption process fits the quasi-second-order kinetic model. The rate control step of adsorption is mainly surface chemical reaction. The adsorption rate of TiO2-Fe3O4-ATP adsorbent can reach more than 65% after 4 times of recycling.
4-Hydroxylcoumarin and its analogs are one of the most active classes of heterocyclic compounds. Many of these compounds have been proved to have a wide range of biological and pharmacological activities, such as antibacterial, anti-tumor, anti-HIV. Herein, 3-arylthio-4-hydroxycoumarin and its analogs were synthesized from stable non-toxic 4-hydroxycoumarins, iodobenzenes and sulfur in a cheap and environmentally friendly fashion.
Organic pollutants in water system are widely viewed as a serious threat to ecologic safety and human health, and it has become a global issue to develop effect technology to control and reduce organic pollutants in water system. Adsorption treatment, based on various porous materials, is believed to be a promising solution to this question. Porous organic polymers(POPs), characterized with high specific surface area, high physical and chemical stability, and easy functionalization, exhibit great potential application in tackling organic pollution of water. In this article, the recent advances were briefly reviewed on the application of POPs in adsorbing organic pollutants such as common organic solvents, pesticides and insecticides, organic dyes in water system.
Fluorescent film sensors have gained extensive attention in the past few decades because of their notable advantages such as high sensitivity, real-time detection, abundant fluorescence signals, easier device implementation, etc. With the fast development and promotion of microfabrication technology, integrated manufacturing, flexible device and Internet of Things, film-based fluorescent sensors have become one of the hot points of sensor studies. Based on the recent progress in our research, this article briefly reviews the development and applications of low-molecular mass compounds-based fluorescent film sensors, of which the applications in the vapor phase detection of explosives, illicit drugs, volatile organic contaminates and some signal molecules of diseases are specially addressed. In addition, problems and challenges limiting the construction of the film sensors are pointed out, and the futures of the relevant studies are prospected.
Thermally activated delayed fluorescence polymers can achieve 100% internal quantum efficiency by utilizing triplet excitons through enhanced reverse intersystem crossing process from the lowest triplet state to singlet state, thereby representing a promising approach toward low-cost and high-effiicnecy light-emitting polymers. Recently, great progress has been made on the material design and device performance of thermally activated delayed fluorescence polymers. This review is aimed to summarize the research progresses on thermally activated delayed fluorescence polymers, with the focus on the molecular design, photophysical characteristic and device performance of mainchain- and sidechain-type thermally activated delayed fluorescence polymers as well as thermally activated delayed fluorescence dendrimers. Finally, the perspectives and the key challenges on developing thermally activated delayed fluorescence polymers are also discussed.
Hot electrons derived from the surface plasmon resonance of metallic nanocrystals have been demonstrated to play a promising role in promoting the efficiency of photocatalytic and photoelectrochemical solar-to-fuel generation. In this review, we try to describe the underlying mechanisms of the generation and relaxation process of hot electrons, give a discussion on the key factors that affect the efficiency of hot electron injection from metal to semiconductor, and provide an overview of the research progress on hot electron-mediated photocatalytic and photoelectrochemical water splitting. This review also outlines the critical limitations in current studies and sheds light on the possible future developments in this research field.
Hydrazine hydrate reduction of metal is mainly applied in the preparation of metal nanoparticles, recovery of metal ions in spent liquid and nuclear fuel. This article reviews the research progress in recent years on the preparation of nano metal materials, the recovery and reuse of metal ions and the used nuclear fuel by hydrazine hydrate as reducing agent or complexing agent in liquid phase reduction process. In liquid phase reduction, the differences and the related mechanisms, characteristics and influencing factors between acidic and alkaline conditions are analyzed and summarized in the process of hydrazine hydrate reduction of metals. This article gives a reference for future research on this field.
The development of renewable clean energy is of great importance for human sustainable development. Nanopores and nanochannels based electrokinetical energy conversion systems provide us new choices for future clean energy resource development. Because these systems can transfer fluidic mechanical energy to electrical energy, they could be applied in the fields such as marine energy, self-driving nano-machines and micro-electrical mechanical systems. The interplay between solid pores and liquid interface is crucial for the energy conversion process inside nanopores and nanochannels. Artificial design, chemical modification and optimization for the interfacial structure of the energy conversion systems are key factors to improve the energy conversion efficiency. With rapid development of nanotechnology and the further study of the physical chemistry of surfaces, we can effectively and precisely prepare nanofluid power generation systems. This review mainly introduced basic concepts and advance progress of nanopores and nanochannels based electrokinetical energy conversion systems. We hope this review will be inspiring for scientists in the area of developing and applying of electrokinetic energy conversion systems, nano-generators, self-actuated nano-machines and wearable devices, etc.
Bi2O2CO3 was synthesized by surfactant-assisted hydrothermal method. The dosage of cationic surfactant cetyltrimethylammonium bromide(CTAB), nonionic surfactant polyethylene glycol 8000(PEG8000), anionic surfactant sodium dodecyl sulfate(SDS), and coupling of SDS with CTAB as well as their influences on crystal plane, morphology, photoabsorption ability and photocatalytic activity of Bi2O2CO3 photocatalyst were investigated. The photocatalytic activity was evaluated by the degradation of rhodamine B solution(10 mg/L) under ultraviolet light irradiation. The results show that when the addition of Bi2O2CO3 is 6 mmol(2.9106 g), modified Bi2O2CO3 with SDS will inhibits the photocatalytic activity. The photocatalytic activity of Bi2O2CO3 is effectively improved by addition of 0.6 g CTAB in the hydrothermal process . A totally 0.3 g of SDS and CTAB can improve the photocatalytic activity of Bi2O2CO3. Addition of 0.3 g PEG8000 also promotes the photocatalytic activity of Bi2O2CO3.
Hydroxybenzoic acid compounds are used widely and have strong polarity. The separation, purification and analysis of their analogues in complex aqueous solution are very difficult. In this paper, magnetic surface molecularly imprinted polymer(MIP) was prepared using nano magnetic Fe3O4 as the carrier and gallic acid(GA) as the template molecule, and characterized by transmission electron microscopy, infrared spectroscopy and magnetic intensity measurement. Then its adsorption properties and adsorptive selectivity were studied by the static adsorption and dynamic adsorption experiments to compare the adsorption properties of GA on MIP with those of 2,4-dihydroxybenzoic acid, salicylic acid and benzoic acid. The results show that the MIP with GA as the template has a core-shell structure with a strong bonding effect, the adsorption process belongs to Langmuir monolayer adsorption and the adsorption kinetics can satisfy the pseudo-second-order kinetic equation model. The MIP exhibits an excellent selectivity for GA, and its adsorption capacity(37.736 mg/g at 318 K) is much higher than those of other structural analogues. The MIP prepared by this method can not only recognize the template molecule, but also be magnetically controlled. The high separation efficiency is applicable to the solid phase extraction.
With the development of electronics towards intelligence, portability and miniaturization, it is necessary to develop high-performance flexible energy storage devices. Due to their high power density, long cycling life, excellent safety, environmentally-friend, and easy realization of flexibility, supercapacitors have attracted increasing attention recently. Graphene-based materials, exhibiting large specific surface area, excellent electrochemical performance and superior mechanical stability, have been widely investigated as electrode materials in flexible all-solid-state supercapacitors. In this review, we introduce the fabrications of graphene-based electrodes, and summarize recent progress on flexible all-solid-state supercapacitors followed by discussing perspective and current challenges of this hot field.
This article reviews recent advances on the synthesis of novel two-dimensional(2D) transitional metal carbides and/or nitrides(MXenes), and their applications for electrochemical energy storage and conversions. These applications could be divided into three main categories: rechargeable batteries, supercapacitors, and electro-catalysis. In these applied aspects, 2D MXenes exhibit promising capabilities due to the unique 2D structure, metallic conductivity, hydrophilic surfaces and other merits. Their electrochemical properties could be enhanced further by strategies of intercalating, compositing, doping, assembling and so on. This provides an avenue to exploit, synthesize and apply novel type of MXenes and MXene-based materials for broad fields, such as electrochemical energy storage and conversions, electronics, and catalysts.
Aptamers are oligonucleotides selected through an in vitro method known as systematic evolution of ligands by exponential enrichment(SELEX), which can recognize target with high specificity and high affinity. Aptamers have attracted wide attention because of their intrinsic advantages including simple synthesis, low molecular mass, high chemical stability, easy biochemical modification and so on. Aptamers can fold into specific two-dimensional or three-dimensional configurations and specifically bind with their targets. With appropriate signal transduction mechanism, aptamers can provide ideal molecular recognition and detection probes for biological research. Fluorescence is a type of detection technology that has several superiorities of high sensitivity, high resolution and easy multiplex detection. With the combination of the molecular recognition capability of aptamers and the outstanding detection performance of fluorescence technology, the aptamer-based fluorescence probes have been widely used in the study of life science. This review highlights the major progress of aptamer-based fluorescence probes in both bioanalysis and bioimaging area, and discusses the current limitations of aptamer probe for applications.