摘要/Abstract

采用微波诱导组装，先将Cu纳米线硫化成空心CuS纳米管，再将片状MoS₂均匀插层并组装在CuS纳米管表面上，形成CuS@MoS₂核壳纳米管，用于可见光（λ>420 nm）催化类芬顿反应降解高浓度污染物罗丹明B（RhB），30 min内降解率达100%.高活性归因于MoS₂独特的多层次结构增加了催化剂对光的吸收，提高了光利用率.同时，MoS₂与CuS之间形成的异质结结构有利于光生电子的转移，抑制了光生载流子的复合.更为重要的是构建了光催化与类芬顿反应的协同作用机制，光催化组分CuS中的铜离子与双氧水作用构成类芬顿循环体系并生成羟基自由基（·OH），光生电子一方面与双氧水反应生成·OH，另一方面与MoS₂活化的分子氧反应产生超氧自由基（·O₂^-），·OH和·O₂^-协同氧化污染物，可大幅度提高污染物去除效率.本工作开发的可循环光催化-芬顿反应体系，为实际污染治理开辟了新途径.
关键词: CuS@MoS₂, 光催化, 类芬顿反应, 协同作用, 微波诱导自组装
CuS@MoS₂ core-shell nanotubes were prepared by microwave-induced assembly techniques in the present work. Firstly, the Cu nanowires were vulcanized into hollow CuS nanotubes. Secondly, the sheet-shaped MoS₂ were uniformly intercalated and assembled onto the surface of CuS nanotubes. The as-prepared CuS@MoS₂ core-shell nanotubes were used in photocatalytic Fenton-like reaction system to remove high-concentration rhodamine B (RhB) in aqueous solution, which exhibited 100% degradation rate within 30 min under visible light (λ>420 nm) irradiation. The morphology and structure of the as-obtained catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometer (EDS) and X-ray diffractometry (XRD). UV-Vis absorption spectroscopy (UV-vis DRS) was used to characterize its basic optical properties. And to further learn the catalytic mechanism and make sure the active species of the photocatalytic Fenton-like reaction system, the heterojunction structure of the catalyst was analyzed and electron spin resonance (ESR) spectrum was carried to prove the existence of superoxide (·O₂^-) species. The high activity could be attributed to the unique multi-layer structure of CuS@MoS₂, corresponding to the enhanced absorption and exciting ability of visible lights. Meanwhile, the heterojunction structure formed between MoS₂ and CuS also promoted the transfer of photogenerated electrons, which could inhibit their recombination with photogenerated holes. More importantly, the cooperation mechanism formed between photocatalysis and Fenton-like reactions may exhibit strong promoting effect. The Cu²⁺ ions in CuS reacted with H₂O₂ to form a Fenton-like cycle, allowing the generation of reactive hydroxyl (·OH) species. While, the photogenerated electrons reacted with both the H₂O₂ and the molecular oxygen activated by MoS₂ to produce ·OH and ·O₂^- species. Both ·OH and ·O₂^- species worked together to oxidize pollutants rapidly. This work developed a recycled photocatalytic Fenton-like reaction system, which may offer new pathway for the treatment of environmental pollution.
Key words: CuS@MoS₂, photocatalysis, Fenton-like reaction, synergistic effect, microwave-induced self-assembly


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