光热协同增强氮化碳锚定FeO_(x)纳米复合材料催化活化过一硫酸盐降解罗丹明B

Photothermal-assisted activation of peroxymonosulfate with FeO_(x) nanoparticles anchored on carbon nitride for degradation of RhB

光热协同催化是一种有效提升活化过一硫酸盐(PMS)高级氧化催化效率的方法。然而,对于常见的过渡金属基催化剂来说,反应过程中常常发生有毒金属离子溶出,限制了这类催化剂在实际水处理中的应用。因此,开发具有高效活化PMS能力的非金属基催化剂至关重要。采用溶胶-热还原法制备一种新型氮化碳锚定FeO_(x)纳米复合物(FeO_(x)/CN)类芬顿催化剂。采用X射线衍射仪、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、氮气吸附-脱附仪和紫外-可见漫反射吸收光谱等测试手段对复合材料的结构、形貌和光吸收性质进行表征。考察光热协同作用下FeO_(x)/CN催化剂活化PMS氧化降解罗丹明B(RhB)的效果。结果表明:在近中性(pH=6)条件下,光热(水浴40℃,λ>420 nm光照)协同辅助反应30 min,CN/FeO_(x)/PMS体系对RhB的去除率达到98.0%。活性自由基捕获实验证明,空穴(h+)和羟基自由基(OH·)在污染物降解中起到决定性作用。

Photothermal-assisted activation of peroxymonosulfate(PMS)is an effective way to promote the advanced catalytic oxidation performance.However,leaching of metal ions is a drawback for currently used metal-based catalysts,which limits their applications for water treatment.Therefore,it is important to develop high-efficient non-metal catalysts for photothermal-assisted PMS activation.Carbon nitride (CN) loaded with FeO_(x) nanoparticles (FeO_(x)/CN) were synthesized by the gelation-pyrolysis method.The as-prepared FeO_(x)/CN catalysts were used to eliminate Rhodamine B(RhB) using the Fenton-like reaction by photothermal-assisted PMS activation.The crystalline structures,morphologies and light adsorption properties of the obtained nanocomposites were analyzed by using X-ray diffractometer,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,N 2 adsorption-desorption and UV-vis spectrophotometer.The results show that the removal rate of RhB by CN/FeO_(x)/PMS system can reach 98.0%under the condition of near neutral(pH=6)and photothermal(40℃water bath and λ>420 nm visible-light irradiation)synergistic auxiliary reaction for 30 min.The trapping experiments demonstrate that holes(h+)and hydroxyl radicals (OH·) are major active species during the PMS activation process.