State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Polytechnic University, Tianjin, PR China; School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin, PR China.
J Hazard Mater. 2013 Nov 15;262:412-9. doi: 10.1016/j.jhazmat.2013.08.076. Epub 2013 Sep 8.
In this study, schwertmannite was prepared through a hydrothermal method and used as a new Fenton-like catalyst in the oxidation of phenol by H2O2. The synthesized iron oxide had a formula of Fe8O8(OH)4.5(SO4)1.75 with a weak crystalline structure as well as a high specific surface area of 325.52 m(2) g(-1). However, schwertmannite has not been used as a Fenton-like catalyst so far, and its catalytic mechanism in the oxidation of phenol is still unknown. This study confirmed that schwertmannite had a good catalytic activity in the oxidation of phenol via a OH radical mechanism. The free radicals could be generated on the schwertmannite surface by ≡ Fe(III) species and in bulk solution by dissolved Fe(III) over a wide pH range. The synthesized schwertmannite also showed a high catalytic ability in the oxidation of phenol in the presence of 0.5M nitrate, chloride or sulfate anions at initial pH 5.0, indicating its potential application in the treatment of high salinity wastewater. In addition, phenol removal percentage could still reach 98% after schwertmannite was successively used for 12 cycles, indicating the good reusability of this catalyst, although a phase transformation of schwertmannite to goethite was observed.
在这项研究中，采用水热法制备了水钠锰矿，并将其用作 H2O2 氧化苯酚的新型类 Fenton 催化剂。合成的氧化铁具有化学式 Fe8O8(OH)4.5(SO4)1.75，具有较弱的结晶结构和 325.52 m(2) g(-1)的高比表面积。然而，迄今为止，水钠锰矿尚未被用作类 Fenton 催化剂，其在苯酚氧化中的催化机制尚不清楚。本研究证实，水钠锰矿通过 OH 自由基机制在苯酚氧化中具有良好的催化活性。自由基可以通过 ≡ Fe(III)物种在水钠锰矿表面生成，也可以通过溶解的 Fe(III)在宽 pH 范围内在体相溶液中生成。在初始 pH 值为 5.0 时，在 0.5M 硝酸盐、氯化物或硫酸盐阴离子存在下，合成的水钠锰矿在氧化苯酚方面也表现出高催化能力，表明其在处理高盐废水方面具有潜在的应用。此外，水钠锰矿在连续使用 12 次后，苯酚去除率仍可达 98%，表明该催化剂具有良好的可重复使用性，尽管观察到水钠锰矿向针铁矿的相转变。
