S-doped Na2Ti6O13@TiO2 core-shell nanorods with enhanced visible light photocatalytic performance.

S-doped Na2Ti6O13@TiO2 (S-TTO) core-shell nanorods, with exposed anatase TiO2 {101} facets, were synthesized by a facile calcination method. It was found that the addition of thiourea as the sulfur precursor was beneficial for the formation of anatase TiO2 with a better crystallinity and the doped sulfur atoms favorably stabilized the anatase structure. The substitution of Ti(4+) by S(6+) in the lattice of S-TTO gave rise to the visible light response and increased the amount of active groups typically as a hydroxyl radical adsorbed onto the catalyst surface. With the formation of the Ti-O-S bond, partial electrons could be transferred from S to O atoms. The electron-deficient S atoms might capture e(-) and thus inhibit the recombination of photogenerated electron-hole pairs. Meanwhile, a closely contacted interface was formed between Na2Ti6O13 and anatase TiO2, resulting in a nanoscale heterojunction structure to speed up the separation rate of photogenerated charge carriers. The exposed anatase {101} facets could act as possible reservoirs of the photogenerated electrons, yielding a highly reactive surface for the reduction of O2 to O2˙(-) and thus the decrease of recombination probability of electron-hole pairs. In addition, the anisotropically shaped titanate nanorods provided a pathway for the quick transport of charge carriers throughout the longitudinal direction. The combined effects of S doping, nano-heterojunction formation and morphology engineering led to an obviously enhanced photocatalytic performance for the degradation of methylene blue (MB) solution under visible light irradiation. The corresponding photocatalytic mechanism was investigated and discussed in detail. The present work may provide an insight into the fabrication of delicate composite photocatalysts with excellent performance.

The nanocomposite of polyaniline and nitrogen-doped layered HTiNbO5 with excellent visible-light photocatalytic performance.

An effective approach has been used to synthesize N-doped HTiNbO5 (denoted as N-HTiNbO5) with a better intercalation property. The synthesis of polyaniline (PANI) with N-HTiNbO5 to form PANI-N-HTiNbO5 lamellar nanocomposites by in situ polymerization using the aniline (ANI) intercalation compound ANI/N-HTiNbO5 as the intermediate has been investigated. The resulting PANI-N-HTiNbO5 nanocomposite showed a better crystallinity with a monolayer of PANI within the interlayers of N-HTiNbO5, because nitrogen doping can affect the surface charge distribution of [TiNbO5](-) layers. The cyclic voltammetry (CV) results indicated that the PANI-N-HTiNbO5 nanocomposite had good redox activity and electrochemical-cycling stability in acidic solution. The visible-light response of the PANI-N-HTiNbO5 nanocomposite was enhanced through N-doping, acid exchange, and the intercalation of PANI. The PANI-N-HTiNbO5 nanocomposite showed the highest activity with 97.8% methylene blue (MB) photodegraded in 170 min under visible light irradiation. The significant enhancement of photocatalytic performance can be attributed to the high efficiency of charge separation, induced by the synergistic effect between PANI and N-HTiNbO5. In addition, the PANI-N-HTiNbO5 nanocomposite had a high thermal and photodegradation stability due to the intercalation reaction at the molecular level.

[Removal of metal ions Cu2+, Cd+ and Pb+ from solutions by sorption on slag].

Batch experiments were carried out to investigate the adsorption kinetics and thermodynamic characteristics of heavy metal ions Cu2+, Cd2+ and Pb2+ on the electric are furnace (EAF) slag from Baoshan Steel Factory. Several kinds of techniques including XRD analysis, BET specific surface analysis and SEM/EDS analysis were employed to determine the physico-chemical and surface characteristics of slag. Results indicated that the adsorption rate of heavy metal ions on the EAF slag was relatively high, and the sorption rate followed the order Cd2+ > Pb2+ > Cu2+. The adsorption kinetics obeyed first-order kinetics model (R2 > 0.99). Adsorption isotherm experiment showed that adsorption isotherm of heavy metal ions on slag fitted Langmuir model, and the maximum adsorption capacity of Cu2+, Cd2+ and Pb2+ was 0.101, 0.058 and 0.120 mmol x g(-1), respectively. The adsorption of heavy metal ions on slag was a spontaneous reaction (deltaG0 < 0) with endotherm (delta H0 < 0) and the increase of enthopy (AS0 > 0). The effect of enthopy was the main driving force of the spontaneous adsorption reaction. The analysis results of SEM/EDS revealed the changes of surface morphology and chemical proportion before and after adsorption. Due to low-cost and high-efficiency, electric are furnace slag showed great potential for the treatment of heavy metal polluted wastewaters.

[Inhibitory effects of liquor cultured with Nelumbo nucifera and Nymphaea tetragona on the growth of Microcystis aeruginosa].

The inhibitory effects of liquor cultured with Nelumbo nucifera and Nymphaea tetragona on the growth of Microcystis aeruginosa have been investigated by measuring the cell number and the chlorophyll a content of Microcystis aeruginosa of culture in the laboratory. The results showed that the inhibitory effects on the growth of Microcystis aeruginosa with different concentration of the liquor cultured with Nelumbo nucifera and Nymphaea tetragona were dissimilar, and an evident phenomenon appeared that low concentrations could promote the growth of Microcystis aeruginosa. However, the inhibitory effects on the growth of Microcystis aeruginosa with continuous liquor cultured with Nelumbo nucifera and Nymphaea tetragona were obvious, which made the algal cell almost lose the capability of photosynthesis, and the inhibitory effects of liquor cultured with Nymphaea tetragona were better than those of Nelumbo nucifera. The scale-up experiment demonstrated that the algal cell received menace and damage by measuring the activities of peroxidase (SOD) and the accumulated contents of malondialdehyde (MDA) of Microcystis aeruginosa in the co-culture. Sterilization methods influenced the algal growth inhibition experiment so that high temperature couldn't replace micropore filter, which explained that the matter excreted by Nelumbo nucifera and Nymphaea tetragona may contain thermally-instabe matter.

One-dimensional BiPO4 nanorods and two-dimensional BiOCl lamellae: fast low-temperature sonochemical synthesis,characterization, and growth mechanism.

Regular BiPO4 nanorods, for the first time, and BiOCl lamellae have been successfully synthesized via a facile sonochemical method in a surfactant/ligand-free system under ambient air. The as-prepared products are characterized by XRD, TEM, SAED, FE-SEM, HRTEM, and Raman spectroscopy. The effects of pH and ultrasound irradiation on the phase and morphology of the products are studied and the sonochemical formation mechanisms of 1D and 2D structures are discussed. TEM data from samples made after different reaction times suggest an ultrasound-induced nucleation and an oriented-attachment growth mechanism.