【摘要】 天然酶作为一种绿色催化剂,能够介导水体中酚类污染物形成酚氧自由基中间体,随后这些活性中间体通过共价偶联机制生成大分子聚合产物.纳米金属氧化物(N-MOs)兼具纳米材料和天然酶"双重身份",有望克服天然酶稳定性差、难回收、易失活和价格昂贵等缺点,高效地催化氧化水体中酚类污染物的转化.本文概述了两种天然酶(过氧化物酶和酚氧化酶)的基本性能及其催化偶联酚类污染物转化的作用机理,系统地探讨了N-MOs的纳米特性及其模拟天然酶催化氧化底物的显色反应、作用效能和影响因素,并阐释了N-MOs作为纳米酶催化氧化酚类污染物转化的最新研究进展及其潜在的应用价值,旨在为拓展和开发新型、有效地纳米酶在环境中的应用提供新的理论基础和技术指导.更多还原

【Abstract】 Natural enzymes(i.e., peroxidase and phenoloxidase) as green catalysts can catalyze the transformation of phenolic contaminants to form phenoxyl radical intermediates, which subsequently yield the covalent binding products by reactive radical-mediated coupling reactions. It is noteworthy that nano-technology has merged to deliver artificial materials for multi-functional applications. In particular, certain nano-materials possess the enzyme-like catalytic performances and substrate specificities. At present, scientists have confirmed that nano-metallic oxides(N-MOs) have dual identities of the nano-materials and natural enzymes, not only mimick the catalytic activity of natural enzymes in the transformation of phenolic contaminants, but also own the physicochemical properties of nano-materials. They are expected to overcome the disadvantage of natural enzymes(e.g., lack of stability, hard-to-recycle, loss of activity, and high cost), and catalyze the transformation of phenolic contaminants efficiently in aqueous solution. For instance, horse radish peroxidases and laccases have been shown to be capable of coupling phenolic contaminants via reactive radical-mediated covalent coupling mechanisms in water. It is thus expected that nano-enzymes wih peroxidase and/or phenoloxidase like activities have the potential to be used in water/wastewater treatment for phenolic contaminants removal. In this paper, we review the basic performance and catalytic coupling mechanisms of peroxidase and phenoloxidase for the transformation of phenolic contaminants in natural aquatic environments. Moreover, the chromogenic reactions, catalytic activities, and influence factors for N-MOs are comparably evaluated, mainly focusing on the latest advances in the transformation and removal of phenolic contaminants in water. It is aimed at providing new theoretical evidences and guidance for the multi-functional applications of nano-enzymes in natural aquatic environments.更多还原