Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan.
Chemistry. 2012 Sep 24;18(39):12330-6. doi: 10.1002/chem.201201414. Epub 2012 Aug 21.
A facile approach has been developed for the preparation of various morphologies of Au-Ag(2)Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO(2) in the presence of various concentrations (16, 8, and 4 M) of a reducing agent (N(2)H(4)) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au-Ag(2)Te NMs by spontaneous redox reactions with Au(3+) and Ag(+) ions sequentially. The Au-Ag(2)Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au-Ag(2)Te NMs (10 μg mL(-1)) provide a death rate of Escherichia coli greater than 80% within 60 min, which is higher than that of 51% for commercial TiO(2) nanoparticles (100 μg mL(-1)). Under light irradiation, the Au NPs in Au-Ag(2)Te NMs enhance the overall photo-oxidation ability of Ag(2)Te NMs through faster charge separation because of good contact between Ag(2)Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au-Ag(2)Te NMs hold great potential for use as efficient antibacterial agents.
已经开发出一种简便的方法来制备具有强光催化活性的各种形貌的 Au-Ag(2)Te 纳米材料 (NMs)。Te NMs（纳米线、纳米笔和纳米稻）是由 TeO(2) 在不同浓度（16、8 和 4 M）的还原剂（N(2)H(4)) 在不同温度（25 和 60°C）下制备的。然后，将这三种 Te NMs 依次通过与 Au(3+)和 Ag(+)离子的自发氧化还原反应来制备 Au-Ag(2)Te NMs。Au-Ag(2)Te 纳米笔在光照射下对亚甲基蓝的降解和活性羟基自由基的形成表现出最高的活性，主要是因为它们在可见光区域最强地吸收光。三种不同形状的 Au-Ag(2)Te NMs（10 μg mL(-1)) 在 60 分钟内提供大于 80%的大肠杆菌死亡率，高于商业 TiO(2)纳米颗粒（100 μg mL(-1)) 的 51%。在光照射下，Au-Ag(2)Te NMs 中的 Au NPs 通过更快的电荷分离增强了 Ag(2)Te NMs 的整体光氧化能力，因为 Ag(2)Te 和 Au 段之间有良好的接触。由于具有高抗菌活性和对正常细胞的低毒性，Au-Ag(2)Te NMs 具有作为高效抗菌剂的巨大潜力。
