Qiong Ouyang,Fangying Kou,Pokeung Eric Tsang,Jintao Lian,Jingyi Xian,Jianzhang Fang,Zhanqiang Fang
Iron-based catalysts (GFe0.5) were successfully prepared from tea polyphenols (TP) and ferric trichloride and used as a heterogeneous Fenton-like catalyst for the degradation of lincomycin (LCM). The results showed that a GFe0.5 dosage of 0.01 g/L could completely degrade a 20 mg/L concentration of LCM in 90 min, and assessment of the toxicity to luminous bacteria showed that the GFe0.5/H 2 O 2 system effectively reduced the toxicity risk posed by this pollutant. The results of transmission electron microscopy , X-ray diffraction (XRD), Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and other characterisations showed that the synthetic material had a triangular structure similar to that of nonacarbonyldiiron, with Fe 2+ , Fe 3+ and organic groups attached to the triangular structure's surface. That is, the present environment-friendly synthesis produces an Fe-based material resembling a mixture of nonacarbonyldiiron and ferrous chloride. Free-radical capture and electron spin resonance experiments confirmed that ·OH was the main active free radical in the degradation mechanism of the iron-based material. Cyclic experiments, inductively coupled plasma and XRD characterisation of the materials after the reaction showed that the loss of free iron was the main reason for the decrease of activity. The free iron in the Fe-based material becomes bound during the reaction, which effectively avoids the excessive consumption of Fe 2+ in the prophase of the Fenton-like reaction, and is the key to both the efficient Fenton-like catalytic ability of GFe0.5, and to preventing the production of iron sludge .
Liangmei Xue,Songbo Li,Shengli An,Ning Li,Huipu Ma,Mengxin Li
Double perovskite oxides with mixed ionic and electronic conductors (MIECs) have been widely investigated as cathode materials for solid oxide fuel cells (SOFCs). Classical Fe-based double perovskites, due to their inherent low electronic and oxygen ionic conductivity, usually exhibit poor electrocatalytic activity. The existence of various valence states of B-site ions modifies the material’s catalytic activity, indicating the possibility of the partial substitution of Fe by higher-valence ions. LaBaFe2−xMoxO5+δ(x= 0, 0.03, 0.05, 0.07, 0.1, LBFMx) is used as intermediate-temperature solid oxide fuel cell (IT-SOFC) cathode materials. At a doping concentration above 0.1, the Mo substitution enhanced the cell volume, and the lattice expansion caused the formation of the impurity phase, BaMoO4. Compared with the parent material, Mo doping can regulate the oxygen vacancy concentration and accelerate the oxygen reduction reaction process to improve the electrochemical performance, as well as having a suitable coefficient of thermal expansion and excellent electrode stability. LaBaFe1.9Mo0.1O5+δis a promising cathode material for IT-SOFC, which shows an excellent electrochemical performance, with this being demonstrated by having the lowest polarization resistance value of 0.017 Ω·cm2at 800 °C, and the peak power density (PPD) of anode-supported single-cell LBFM0.1|CGO|NiO+CGO reaching 599 mW·cm−2.