Transparent Glass with the Growth of Pyramid-Type MoS2 for Highly Efficient Water Disinfection under Visible-Light Irradiation.

Abstract

Water disinfection is of great importance for human health and daily life. Photocatalysts with high efficiency, environmental protection, and narrow bandgaps are critical for practical watertreatment. Here, a general approach is reported for the direct growth of pyramid-type MoS2 (pyramid MoS2) on transparent glass by chemical vapor deposition (CVD). The pyramid MoS2 exhibits a smaller bandgap and higher bactericidal activity than most TiO2-based photocatalysts. The adjustable-bandgap nature of two-dimensional (2-D) MoS2 can harvest a wide spectrum of sunlight and provide more active sites with which to generate reactive oxygen species (ROS) for bacterial death in water. Furthermore,silver (Ag) with several nanometers thicknesses is thermally evaporated on the pyramid MoS2, which can greatly facilitate electron-hole pair separation to generate more ROS and has a certain bactericidal effect. With our established approach, under simulated visible light, more than 99.99% of Escherichia coli can be successfully deactivated in 40 min, with an effective mass per unit of less than 0.7 mg L-1 in a 0.9 wt % NaCl solution. Besides, for the first time, the generation of ROS is confirmed with in situ Raman spectroscopy on pyramid MoS2@Ag glass, and the related bactericidal mechanism is present as well.