Lei Liao

Aqueous synthesis of functionalized copper sulfide quantum dots as near-infrared luminescent probes for detection of Hg 2+ , Ag + and Au 3+

Stable water-soluble copper sulfide(Cu2S) quantum dots(QDs) with near-infrared emission were synthesized using N-acetyl-L-cysteine(NAC) as a modifier in aqueous solution and nitrogen atmosphere at room temperature. The product was characterized by TEM, XRD, XPS, FT-IR, FL and UV-VIS spectrometers. Effects of preparation conditions such as pH values, the molar ratio of reactants, temperature, and metal ions on the fluorescence properties of Cu2S QDs were discussed. Under optimal conditions, the prepared Cu2S QDs with average diameter about 2–5 nm show a near-infrared emission at 770 nm with the excitation wavelength of 466 nm, and have a good detection sensitivity for ions of Hg2+, Ag+ and Au3+, based on the characteristic of fluorescence quenching. The fluorescence quenching mechanism was proposed via electron transfer with cation exchange, which based on the theory of Hard-Soft-Acid-Base (HSAB) and Ksp value of metal–sulfide.

Removal of Organic Dyes by Nanostructure ZnO-Bamboo Charcoal Composites with Photocatalysis Function

Composites of nanostructure zinc oxide (nano-ZnO) and bamboo charcoal (BC) were successfully prepared via impregnation-precipitation method. The products were characterized by XRD, SEM, and EDS. Rhodamine B (RhB) and acid fuchsin (AF) were selected as the organic dyes of photocatalysis degradation under the irradiation of ultraviolet light (UV). The influence of particle size of BC, irradiation time, pH value of the solution, and additive amount of H2O2 on removal of the dyes has been studied. The results show that smaller particle size of BC in the composites has a better removal effect. The composites possess the highest removal capacity for RhB and AF under the conditions of pH = 2 and pH = 5.4, respectively. The optimum additive amount of H2O2 for 5 mL RhB and AF was 0.050 mL and 0.1 mL, with a removal rate of 93% and 99%, respectively.

Manganese(II) enhanced fluorescent nitrogen-doped graphene quantum dots: a facile and efficient synthesis and their applications for bioimaging and detection of Hg2+ ions

Manganese ion (Mn2+) bonded nitrogen-doped graphene quantum dots (Mn(II)-NGQDs) with water solubility have been successfully synthesized by a simple, one-pot hydrothermal carbonization, using sodium citrate, glycine and manganese chloride as raw materials. The photoluminescence (PL) characteristics of Mn(II)-NGQDs were studied in detail. The resulting Mn(II)-NGQDs show a remarkably enhanced PL intensity and quantum yield (QY = 42.16%) compared with the product without Mn(II)-doped (named as NG, QY = 27.06%) and the product doped with other metal ions. The Mn(II)-NGQDs not only display low toxicity and high cellular uptake efficiency for fluorescence live cell imaging in biological evaluations but also exhibit a fast, highly selective and sensitive fluorescence quenching effect toward Hg2+ ions, with a detection limit of 3.4 × 10−8 mol L−1.

Study on the Photocatalytic Properties of Nano-CdS Crack-Free Thin Films for Removal of Rhodamine B

Nano-CdS crack-free thin films were deposited on the conductive glass substrate with a two-electrodes DC electrochemical deposited method at low temperature (<100°C). The structure and properties of thin film catalysts were characterized by X-ray diffraction (XRD), SEM and AFM. Photocatalytic reactivities of nano-CdS thin film were conducted for removal of Rhodamine B (RB) in aqueous solution under ultraviolet light irradiation. The effect of the concentration and pH of the RB solution, the ultraviolet light, the exposure time, the size and the reusability of thin films on the degradation of RB were studied. It was found out that the exposure time, the light wavelength, the pH of RB solution and thin film’s size have much influence on the degradation. Reusability experiments show that the catalyst has well recycle characterization.

Synthesis of MoSe2-MoO2@Biomass-Derived Honeycombed Carbon Composite and its Application in LIB

MoSe2-MoO2@ honeycombed carbon composites have been obtained, in which the honeycombed carbon derived from sisal fiber services as a conductive matrix. The detailed preparation process is reported in this paper. The prepared composites are characterized by XRD, Raman, EDX, SEM and XPS analysis. It is obtained that the hybrid MoO2-MoSe2 with nanoparticle and hierarchical flower-like structures are coating on the surface of sisal fiber carbon (SFC). The electrochemical behavior of the lithium ion battery using MoO2-MoSe2@SFC as electrode has been studied. The electrode exhibits a retention capacity of 494 mAh/g at the current density of 50 mA/g over 30 cycles, while a capacity of 258 mAh/g is obtained at the current density of 1 A/g. The roles of the MoO2 and MoSe2 in electrochemical behavior are discussed respectively.

Preparation and Electrochemical Properties of the Adjusted Fe 3 O 4 /C Composites

Fe3O4/C composites were synthesized by one-pot hydrothermal method. The growth mechanism and electrochemical properties were investigated. The results indicated that the dosage of urea leaded to the formation of nanostructure and the electrochemical performances differences.

One-Step Hydrothermal Controlled Synthesis of HgTe Nanorods

This paper describes a one-step hydrothermal synthesis of rod-shaped HgTe nanocrystals (NCs). X-ray powder diffraction (XRD), field scanning electron microscopy (FE-SEM), transition electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX) have been used to characterize the HgTe NCs. The length, diameter, surface roughness and the aspect ratio of the HgTe nanorods are well controlled through Te precursor, reaction time and reductant.

The Research of Biological Method Degradation on Cooking Fume

Experiments according to the current domestic situation of bio-treatment cooking fume, domesticated the activated sludge which taken from the oxidation ditch of the sewage treatment plant by using the simulated cooking fumes, discussed the concentration and morphology variation of activated sludge, researched the degradation ability of microorganism on cooking fume, the change of bacteria amount were studied in the whole process. Research showed that the sludge concentration decreased to 2878mg/L when the acclimatization time reached 50days; outlet and inlet oil concentration were consistent when the acclimatization time reached 30days while liquid fume concentration decreased to 8.436mg/L, the degradation rate of activated sludge on liquid fume was about 75% after 30 days; Microbial biomass increased first and then down become stable finally.

Electrodeposited Crack-Free CdS Thin Films Using Organic Solvents

Crack-free CdS thin films have been electrodeposited on conductive glass substrate by CdCl2 and S powder in dimethylformamide (DMF) and mixed organic solvents with appropriate volume ratio at temperatures lower than 100°C. The effects of solvents on the cracks and the photovoltaic property and catalytic property of CdS thin film are investigated. The results show that the crack-free CdS thin films have higher photoluminescence (PL) emission intensity and better photoelectrichemistry and photocatalytic activities for degradation organic dyes of Fuchsin acid, phenol red and crystal violet than thin films with cracks.