In-plasma-catalysis for NO x degradation by Ti3+ self-doped TiO2-x /γ-Al2O3 catalyst and nonthermal plasma.

In an attempt to realize the efficient treatment of NO x , a mixed catalyst of Ti3+ self-doped TiO2-x and γ-Al2O3 was constructed by reducing commercial TiO2. The degradation effect on NO x was evaluated by introducing the mixed catalyst into a coaxial dual-dielectric barrier reactor. It was found that the synthesized TiO2-x could achieve considerable degradation effects (84.84%, SIE = 401.27 J L-1) in a plasma catalytic system under oxygen-rich conditions, which were better than those of TiO2 (73.99%) or a single plasma degradation process (26.00%). The presence of Ti3+ and oxygen vacancies in TiO2-x resulted in a relatively narrow band gap, which contributed to catalyzing deeply the oxidation of NO x to NO2 - and NO3 - during the plasma-induced "pseudo-photocatalysis" process. Meanwhile, the TiO2-x showed an improved discharge current and promoted discharge efficiency, explaining its significant activation effect in the reaction. Reduced TiO2-x could achieve an impressive degradation effect in a long-time plasma-catalysis process, and still maintained its intrinsic crystal structure and morphology. This work provides a facile synthesis procedure for preparing Ti3+ self-doped TiO2-x with practical and scalable production potential; moreover, the novel combination with plasma also provides new insights into the low-temperature degradation of NO x .

Hydrothermal synthesis of a novel nanolayered tin phosphate for removing Cr(iii).

In this work, an outstanding nanolayered tin phosphate with 15.0 Å interlayer spacing, Sn (HPO4)2·3H2O (SnP-H+), has been synthesized by conventional hydrothermal method and first used in the adsorptive removal of Cr(iii) from aqueous solution. A number of factors such as contact time, initial concentration of Cr(iii), temperature, pH, and ionic strength on adsorption were investigated by batch tests. Moreover, the isothermal adsorption characteristics and kinetic model of Cr(iii) onto SnP-H+ were studied. The results showed that the adsorption of Cr(iii) by SnP-H+ was in accordance with the Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. The adsorption capacity of Cr(iii) onto SnP-H+ at temperature 40.0 °C and pH 3.0 could reach 81.1 mg g-1. And the distribution coefficient K d was 23.0 g L-1. Overall, experiments certified that SnP-H+ was an excellent adsorbent that can effectively remove Cr(iii) from aqueous solution.