Hui Ling Liu

Preparation and Photocatalysis of Sulfur-Doped Nano-TiO2/Ti Film

Owing to the defects of the fixed TiO2 photocatalysts, the research employed the approach of anodic oxidation to produce high efficiend S-TiO2/Ti ceramic film oxidized on the surface of titanium, in order to make the absorbable spectrum of light catalyst spread to the visible region and constrain the high recombination rate of electron-hole pairs during photoreaction. The surface appearance and the distribution of elements have been checked with scanning electron microscopy. The microcrystal structure of the films has been checked with XRD. The results showed that the main components of sulfur-doped catalyzer were rutile and anatase, meanwhile, the sulfur element distributing on the film was fairly uniform. Films of S-TiO2 photocatalysis reduction K2CrO4 revealed that with the amount of S-contained increased, the rate of reduction K2CrO4 decreased under ultraviolet light while that increased under visible light. It was found that the highest reduction rate of K2CrO4 was achieved through an optimal Na2S2O3 dosage of 0.6g/L in ceramic film prepared processes.

Preparation and Photocatalytic Property of WO3-TiO2 /Ti Ceramic Film via Anodic Oxidation Treatment

The high efficient WO3-TiO2/Ti ceramic film was prepared on the surface of titanium by the approach of anodic oxidation in order to make the absorbable spectrum of catalyst spread to the visible region and restrain the high recombination rate of electron-hole pairs during photoreaction. The surface morphology and the distribution of elements were studied with scanning electron microscopy and energy dispersive spectroscopy. The phase composition of the films was investigated with XRD. The results showed that the main components in the coating were WO3, rutile TiO2 and anatase TiO2. The compound WO3-TiO2/Ti ceramic film enlarged the range of the reacting visible light and increased the absorbing intensity. The rhodamine B was successfully photodegraded under visible light irradiation by WO3-TiO2/Ti catalyst films. It was found that the highest degradation rate of rhodamine B was achieved through an optimal W dosage of 4.2 %(wt %) in WO3-TiO2/Ti ceramic film. It was also confirmed that the recombination rate of electron-hole pairs in WO3-TiO2/Ti ceramic film declined due to the existence of WO3 in TiO2/Ti ceramic film.

Catalytic Dechlorination of Monochloroacetic Acid by Film–Supported Pd/Fe Bimetallic Nanoparticles

Three novel kinds of support film, including PVDF-PAA film, PVDF·TiO2–PAA film and PVDF–g–AA film, were synthesized and used to immobilize the Pd/Fe bimetallic nanoparticles (NPs). The immobilized Pd/Fe bimetallic NPs systems were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle analysis, and X-ray photoelectron spectroscopy. The dechlorination efficiency of the immobilized bimetallic NPs systems were tested and discussed by dechlorinating monochloroacetic acid (MCAA). Comparing with free suspended Pd/Fe NPs, bimetallic NPs with support films appeared better catalytic dechlorination efficiency, and the dechlorination efficiencies of 10 mg/L MCAA in 120 min by Pd/Fe NPs immobilized in PVDF–PAA film, PVDF·TiO2–PAA film and PVDF–g–AA film were 56.33%, 71.01% and 75.51%, respectively.

Preparation and Photoelectrocatalytic Performance of TiO2 Nano-Tubes Arrays Electrode

Highly ordered TiO2 nano-tubes arrays (TNTAs) electrode was fabricated through anodization. The effects of some experimental parameters on photocatalytic (PC) activity and photoelectrocatalytic (PEC) activity were investigated in detail. It was found that the optimum preparng conditions were as followed: the applied voltage, water content, fluoride concentration, anodization time and reaction temperature was 20 V, 40 vol%, 0.5 wt%, 2 h and 40 °C, respectively. In addition, the TNTAs electrode exhibited high PC and PEC activities, in which 39.1% and 65.7 % of methyl blue (MB) could be mineralized, respectively. The high PC and PEC activities could be attributed to the highly nano-tubular structure and mixed crystallite composition, which could facilitate the separation and transfer of the photogenerated charge carriers.

Study on Morphologies of Palladium Coated Foam Nickel Cathodes for Dechlorination of 2,4-Dichlorophenol

Electrolytically deposited palladium on polypyrrole film, which is electropolymerized using potentiostatic method, covered foam nickel electrode as a support was used as cathode for the electrocatalytic hydrodechlorination of 2, 4-dichlorophenol in aqueous solution. It is well known that the morphologies of polypyrrole films have dramatic influences on the dispersion of metals and the performance of the composite electrode. The influence of applied potential, temperature and polymerization time on the morphology of the films was studied by scanning electron microscopy (SEM). The fundamental electrocatalytic hydrodechlorination (ECH) results indicated that the electrocatalytic activity of Pd loaded polypyrrole foam nickel electrode is excellent for dechlorination of 2,4-dichlorophenol. The present study shows a promising choice of this kind of composite electrode for ECH.

A Method for Determination of Penicillin G Residue in Waste Penicillium chrysogenum Using High Performance Liquid Chromatography

In this study, a rapid and selective method has been developed to determine PENG residues in waste penicillium chrysogenum by using SPE cleanup strategy followed by HPLC. Furthermore, some parameters which influenced the extraction efficiency including extraction mode, solvent and time, while washing solution and eluting solution for SPE were systematically investigated. It should be noted that the extraction process was carried out in a single step by mixing the extraction solvent acetonitrile: formic acid in aqueous solution and chrysogenum samples under ultrasound. The SPE procedure was conducted using Oasis HLB as the clean up cartridge, n-hexane as washing solution, and mixture of acetonitrile and methanol as eluting solution. Under the optimized conditions, the linear of PENG are in the range of 0.1-2000 μg/mL, with the correlation was R2>0.99. In addition, the recoveries of PENG in these samples at three fortification levels of 800-1800mg/kg were 74.98% to 113.47% are obtained, respectively. Moreover, a limits of detection (0.006 mg/kg) and quantification (0.02 mg/kg) could be achieved.

Glass-Ceramics Obtained from Sewage Sludge and its Characteristics Affected by Alkalinity

Sewage sludge was tested as component for producing glass-ceramics with the addition of analytic reagent CaO to solve the sewage sludge disposal problems. The effect of alkalinity (Ak=mCaO/mSiO2) on the characteristics of the glass-ceramics was investigated. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to investigate thermal behavior and crystalline phase of the samples. It was found that the degree and characteristics of crystals in vitrified sludge significantly correlate to the alkalinity of the raw materials. The glass-ceramics with Ak = 0.36 possessed the best physical and chemical properties.

Inhibition and Recovery of Nitrification during the Process of Sludge Reduction Induced by a Metabolic Uncoupler, 2,6-Dichlorophenol (2,6-DCP)

2,6-DCP was found to be an efficient metabolic uncoupler to reduce sludge production. 20mg/L 2,6-DCP could reduce sludge production about 34.62%, however, it also affected nitrification seriously, the nitrification inhibition was about 76.17% compared to control. Environmental factors, temperature and pH, were varied to repair nitrification. The nitrification inhibition was decreased to 45.7% at 28±1 ◦C and pH=8.5±0.2. Nitrification inhabitation was further decreased to 30% when the 2,6-DCP concentration reduced to 10 mg/L, the sludge reduction also decreased to17.9%. The 30-day operation data indicated that 10mg/L 2,6-DCP can also effectively reduced the sludge production about 17.9% with the COD removal efficiency decreased about 6.99% and nitrification inhabitation was about 30.91%. It shouldn’t only consider the sludge reduction when selecting the concentration of metabolic uncoupler. The application of metabolic uncoupler for sludge reduction should be cautious and need further study.

Pd/Fe Nanoparticles as Catalytic Reductant Immobilized in Hydrophilized PVDF Membrane to Dechlorinate Monochloroacetic Acid

PVDF membrane was modified by hydrophilization method, Pd/Fe nanoparticles were successful immobilized in hydrophilized PVDF membrane as catalytic reduant to dechlorinate monochloroacetic acid, the Pd/Fe nanoparticles characterized by Scanning Electron Microscopy (SEM). The hydrophilized PVDF membrane was characterized by Fourier Transform Infrared Spectroscopy (FT-IR). The PVDF membrane immobilized Pd/Fe nanoparticles (NPs) as caralytic reducant was used to dechlorinate monochloroacetic acid (MCAA), the monochloracetic acid dechlorination efficiency was high.

Nitrogen-Doped Nano-TiO2 Ceramic Film: Fabrication and Application to Photocatalysis

Owing to the defects of the fixed TiO2 photocatalysts, the research employed the approach of anodic oxidation to produce high efficiend N-TiO2/Ti ceramic film oxidized on the surface of titanium, in order to make the absorbable spectrum of light catalyst spread to the visible region and constrain the high recombination rate of electron-hole pairs during photoreaction. The surface appearance and the distribution of elements have been checked with scanning electron microscopy and EPMA. The microcrystal structure of the films has been checked with XRD. The results showed that the main components of nitrogen-doped catalyzer were rutile and anatase, meanwhile, the nitrogen element distributing on the film was fairly uniform. Films of N-TiO2 photocatalysis reduction K2CrO4 revealed that with the amount of N-contained increased, the rate of reduction K2CrO4 decreased under ultraviolet light while that increased under visible light. It was found that the highest reduction rate of K2CrO4 was achieved through an optimal (NH4)2S2O8 dosage of 0.4g/L in ceramic film prepared processes.