Abstract: A series of ammonia-modified multi-walled carbon nanotubes was prepared via hydrothermal method.Their catalytic activity was evaluated by oxalic acid degradation in aqueous solution in the presence of ozone.It was found that the reaction process can be fitted to zero-order reaction kinetics.The apparent zero-order rate constant had a positive relation with the basic groups and pH value at zero charge point(pHPZC)of the catalysts.On this basis，it can be concluded that the significant enhancement of oxalic acid degradation is achieved by hydrothermal treatment with ammonia.The reason could be that the method promotes formation of basic groups and increase of pHPZC.

Key words: multi-walled carbon nanotubes, ammonia, hydrothermal treatment, oxalic acid, ozone, degradation

摘要： 采用水热方法制备了一系列用浓氨水改性的多壁碳纳米管催化剂，该催化剂的活性通过非均相催化臭氧化降解水溶液中的草酸来进行评价。降解过程符合零级反应动力学模型，且催化剂的表观动力学常数与其表面碱性基团数量以及零电位pH值（pHPZC）呈正相关。为此，可断定用浓氨在水热条件下处理多壁碳纳米管能明显提高催化臭氧降解草酸能力是因为提高了催化剂的表面碱性基团数量和pHPZC。

关键词: 多壁碳纳米管, 浓氨水, 水热处理, 草酸, 臭氧, 降解