Photocatalytic activity of molybdenum disulfide nanotube arrays with different wall thicknesses under visible light

Light trapping based on nanostructure has emerged as an effective method to improve light absorption of the photocatalytic devices. Herein, molybdenum disulfide nanotube arrays with different wall thicknesses were successfully synthesized by changing reactant concentration from 50 % to 150 %. The nanotubes overcame aggregation of the nanosheets, offered multiple scattering centers and enabled multiple refraction of light, leading to excellent light harvest in the visible range and molecule absorption efficiency as high as 21.0 %. The photodegradation efficiency of methylene blue as catalyzed by the nanotubes was modulated by the wall thickness, in which the highest degradation efficiency of 69.6 % and the largest kinetic constant of 5.516 x10-- 3 min-- 1 & sdot;cm- 2 were achieved for the thinnest wall. The analysis revealed that the photocatalytic activity of the nanotube arrays was dominated by the dye absorption, environment, light excitation and charge recombination, which would provide structural design for their applications in optoelectronics and photo- catalysis.