Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light
Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light
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DOI：
10.1038/nnano.2016.138
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发表时间：
2016-12-01
影响因子：
38.3
通讯作者：
Cui, Yi
中科院分区：
文献类型：
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作者：
Liu, Chong;Kong, Desheng;Cui, Yi
太阳能在大多数气候条件下都很容易获得，可用于水净化。然而，饮用水的太阳能消毒主要依赖于紫外线，其仅占总太阳能的4%，这导致处理速度缓慢。因此，非常需要开发可以收集可见光用于水消毒的新材料，从而加速太阳能水净化。在这里，我们展示了多层垂直排列的MoS 2（FLV-MoS 2）薄膜可用于收集整个可见光光谱（类似于50%的太阳能），并实现高效的水消毒。通过减小畴尺寸，MoS 2的带隙从1.3 eV增加到1.55 eV，这允许FLV-MoS 2产生活性氧物质（ROS）用于水中的细菌灭活。FLV-MoS 2显示出比散装MoS 2更好的指示细菌的对数灭活效率15倍，并且与广泛使用的TiO 2相比，在可见光和太阳光照射下细菌的灭活更快。此外，通过在FLV-MoS 2顶部使用5 nm的铜膜作为催化剂以促进电子-空穴对分离并促进ROS的产生，消毒率进一步提高了六倍。用我们的方法，我们实现了水消毒>99.999%的细菌灭活在20分钟内与少量的材料（1.6毫克l（-1））在模拟可见光下。
Solar energy is readily available in most climates and can be used for water purification. However, solar disinfection of drinking water mostly relies on ultraviolet light, which represents only 4% of the total solar energy, and this leads to a slow treatment speed. Therefore, the development of new materials that can harvest visible light for water disinfection, and so speed up solar water purification, is highly desirable. Here we show that few-layered vertically aligned MoS2 (FLV-MoS2) films can be used to harvest the whole spectrum of visible light (similar to 50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS2 was increased from 1.3 to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS2 to generate reactive oxygen species (ROS) for bacterial inactivation in the water. The FLV-MoS2 showed a 15 times better log inactivation efficiency of the indicator bacteria compared with that of bulk MoS2, and a much faster inactivation of bacteria under both visible light and sunlight illumination compared with the widely used TiO2. Moreover, by using a 5 nm copper film on top of the FLV-MoS2 as a catalyst to facilitate electron-hole pair separation and promote the generation of ROS, the disinfection rate was increased a further sixfold. With our approach, we achieved water disinfection of >99.999% inactivation of bacteria in 20 min with a small amount of material (1.6 mg l(-1)) under simulated visible light.