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Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light

Abstract

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 (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.

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Figure 1: FLV-MoS2 disinfection schematic.
Figure 2: FLV-MoS2 morphology and band-structure characterization.
Figure 3: FLV-MoS2 disinfection performance.
Figure 4: Performance enhancement of FLV-MoS2 by 5 nm of catalysts of Cu or Au.

References

  1. Shannon, M. A. et al. Science and technology for water purification in the coming decades. Nature 452, 301–310 (2008).

    Article  CAS  Google Scholar 

  2. Schwarzenbach, R. P. et al. The challenge of micropollutants in aquatic systems. Science 313, 1072–1077 (2006).

    Article  CAS  Google Scholar 

  3. Liu, C. et al. Conducting nanosponge electroporation for affordable and high-efficiency disinfection of bacteria and viruses in water. Nano Lett. 13, 4288–4293 (2013).

    Article  CAS  Google Scholar 

  4. Liu, C. et al. Static electricity powered copper oxide nanowire microbicidal electroporation for water disinfection. Nano Lett. 14, 5603–5608 (2014).

    Article  CAS  Google Scholar 

  5. Logan, B. E. & Elimelech, M. Membrane-based processes for sustainable power generation using water. Nature 488, 313–319 (2012).

    Article  CAS  Google Scholar 

  6. McGuigan, K. G. et al. Solar water disinfection (SODIS): a review from bench-top to roof-top. J. Hazard. Mater. 235, 29–46 (2012).

    Article  Google Scholar 

  7. Sinha, R. P. & Hader, D. P. UV-induced DNA damage and repair: a review. Photochem. Photobiol. Sci. 1, 225–236 (2002).

    Article  CAS  Google Scholar 

  8. Hijnen, W. A. M., Beerendonk, E. F. & Medema, G. J. Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: a review. Water Res. 40, 3–22 (2006).

    Article  CAS  Google Scholar 

  9. Silverman, A. I., Peterson, B. M., Boehm, A. B., McNeill, K. & Nelson, K. L. Sunlight inactivation of human viruses and bacteriophages in coastal waters containing natural photosensitizers. Environ. Sci. Technol. 47, 1870–1878 (2013).

    Article  CAS  Google Scholar 

  10. Dong, S. Y. et al. Recent developments in heterogeneous photocatalytic water treatment using visible light-responsive photocatalysts: a review. RSC Adv. 5, 14610–14630 (2015).

    Article  CAS  Google Scholar 

  11. Dong, S. Y. et al. Designing three-dimensional acicular sheaf shaped BiVO4/reduced graphene oxide composites for efficient sunlight-driven photocatalytic degradation of dye wastewater. Chem. Eng. J. 249, 102–110 (2014).

    Article  CAS  Google Scholar 

  12. Dong, S. Y. et al. ZnSnO3 hollow nanospheres/reduced graphene oxide nanocomposites as high-performance photocatalysts for degradation of metronidazole. Appl. Catal. B 144, 386–393 (2014).

    Article  CAS  Google Scholar 

  13. Chong, M. N., Jin, B., Chow, C. W. K. & Saint, C. Recent developments in photocatalytic water treatment technology: a review. Water Res. 44, 2997–3027 (2010).

    Article  CAS  Google Scholar 

  14. Malato, S., Fernandez-Ibanez, P., Maldonado, M. I., Blanco, J. & Gernjak, W. Decontamination and disinfection of water by solar photocatalysis: recent overview and trends. Catal. Today 147, 1–59 (2009).

    Article  CAS  Google Scholar 

  15. Wardman, P. Reduction potentials of one-electron couples involving free-radicals in aqueous-solution. J. Phys. Chem. Ref. Data 18, 1637–1755 (1989).

    Article  CAS  Google Scholar 

  16. Wood, P. M. The potential diagram for oxygen at pH-7. Biochem. J. 253, 287–289 (1988).

    Article  CAS  Google Scholar 

  17. Lawless, D., Serpone, N. & Meisel, D. Role of OH radicals and trapped holes in photocatalysis—a pulse radiolysis study. J. Phys. Chem. 95, 5166–5170 (1991).

    Article  CAS  Google Scholar 

  18. Liao, H. D. & Reitberger, T. Generation of free OHaq radicals by black light illumination of Degussa (Evonik) P25 TiO2 aqueous suspensions. Catalysts 3, 418–443 (2013).

    Article  CAS  Google Scholar 

  19. Chen, X. & Mao, S. S. Titanium dioxide nanomaterials: synthesis, properties, modifications, and applications. Chem. Rev. 107, 2891–2959 (2007).

    Article  CAS  Google Scholar 

  20. Li, Q., Xie, R. C., Ll, Y. W., Mintz, E. A. & Shang, J. K. Enhanced visible-light-induced photocatalytic disinfection of E. coli by carbon-sensitized nitrogen-doped titanium oxide. Environ. Sci. Technol. 41, 5050–5056 (2007).

    Article  CAS  Google Scholar 

  21. Cong, Y., Zhang, J. L., Chen, F., Anpo, M. & He, D. N. Preparation, photocatalytic activity, and mechanism of nano-TiO2 co-doped with nitrogen and iron (III). J. Phys. Chem. C 111, 10618–10623 (2007).

    Article  CAS  Google Scholar 

  22. Asahi, R., Morikawa, T., Ohwaki, T., Aoki, K. & Taga, Y. Visible-light photocatalysis in nitrogen-doped titanium oxides. Science 293, 269–271 (2001).

    Article  CAS  Google Scholar 

  23. Choi, J., Park, H. & Hoffmann, M. R. Effects of single metal-ion doping on the visible-light photoreactivity of TiO2 . J. Phys. Chem. C 114, 783–792 (2010).

    Article  CAS  Google Scholar 

  24. Yu, J. C. et al. Efficient visible-light-induced photocatalytic disinfection on sulfur-doped nanocrystalline titania. Environ. Sci. Technol. 39, 1175–1179 (2005).

    Article  CAS  Google Scholar 

  25. Hayden, S. C., Allam, N. K. & El-Sayed, M. A. TiO2 nanotube/CdS hybrid electrodes: extraordinary enhancement in the inactivation of Escherichia coli. J. Am. Chem. Soc. 132, 14406–14408 (2010).

    Article  CAS  Google Scholar 

  26. Chen, C. et al. Synthesis of visible-light responsive graphene oxide/TiO2 composites with p/n heterojunction. ACS Nano 4, 6425–6432 (2010).

    Article  CAS  Google Scholar 

  27. Yu, J. G., Dai, G. P. & Huang, B. B. Fabrication and characterization of visible-light-driven plasmonic photocatalyst Ag/AgCl/TiO2 nanotube arrays. J. Phys. Chem. C 113, 16394–16401 (2009).

    Article  CAS  Google Scholar 

  28. Mor, G. K., Varghese, O. K., Paulose, M., Shankar, K. & Grimes, C. A. A review on highly ordered, vertically oriented TiO2 nanotube arrays: fabrication, material properties, and solar energy applications. Sol. Energy Mater. Sol. Cells 90, 2011–2075 (2006).

    Article  CAS  Google Scholar 

  29. Tao, J. G., Luttrell, T. & Batzill, M. A two-dimensional phase of TiO2 with a reduced bandgap. Nature Chem. 3, 296–300 (2011).

    Article  CAS  Google Scholar 

  30. Dette, C. et al. TiO2 anatase with a bandgap in the visible region. Nano Lett. 14, 6533–6538 (2014).

    Article  CAS  Google Scholar 

  31. Huang, J. H., Ho, W. K. & Wang, X. C. Metal-free disinfection effects induced by graphitic carbon nitride polymers under visible light illumination. Chem. Commun. 50, 4338–4340 (2014).

    Article  CAS  Google Scholar 

  32. Wang, X. C. et al. A metal-free polymeric photocatalyst for hydrogen production from water under visible light. Nature Mater. 8, 76–80 (2009).

    Article  CAS  Google Scholar 

  33. Xia, D. H. et al. Red phosphorus: an Earth-abundant elemental photocatalyst for ‘green’ bacterial inactivation under visible light. Environ. Sci. Technol. 49, 6264–6273 (2015).

    Article  CAS  Google Scholar 

  34. Gao, P., Liu, J. C., Sun, D. D. & Ng, W. Graphene oxide–CdS composite with high photocatalytic degradation and disinfection activities under visible light irradiation. J. Hazard. Mater. 250, 412–420 (2013).

    Article  Google Scholar 

  35. Gao, P., Ng, K. & Sun, D. D. Sulfonated graphene oxide–ZnO–Ag photocatalyst for fast photodegradation and disinfection under visible light. J. Hazard. Mater. 262, 826–835 (2013).

    Article  CAS  Google Scholar 

  36. Wang, W. J. et al. Visible-light-driven photocatalytic inactivation of E. coli K-12 by bismuth vanadate nanotubes: bactericidal performance and mechanism. Environ. Sci. Technol. 46, 4599–4606 (2012).

    Article  CAS  Google Scholar 

  37. Wang, W. J., Yu, J. C., Xia, D. H., Wong, P. K. & Li, Y. C. Graphene and g-C3N4 nanosheets co-wrapped elemental α-sulfur as a novel metal-free heterojunction photocatalyst for bacterial inactivation under visible-light. Environ. Sci. Technol. 47, 8724–8732 (2013).

    Article  CAS  Google Scholar 

  38. Radisavljevic, B., Radenovic, A., Brivio, J., Giacometti, V. & Kis, A. Single-layer MoS2 transistors. Nature Nanotechnol. 6, 147–150 (2011).

    Article  CAS  Google Scholar 

  39. Wang, Q. H., Kalantar-Zadeh, K., Kis, A., Coleman, J. N. & Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nature Nanotechnol. 7, 699–712 (2012).

    Article  CAS  Google Scholar 

  40. Jaramillo, T. F. et al. Identification of active edge sites for electrochemical H2 evolution from MoS2 nanocatalysts. Science 317, 100–102 (2007).

    Article  CAS  Google Scholar 

  41. Kong, D. S. et al. Synthesis of MoS2 and MoSe2 films with vertically aligned layers. Nano Lett. 13, 1341–1347 (2013).

    Article  CAS  Google Scholar 

  42. Wang, H. T. et al. Electrochemical tuning of vertically aligned MoS2 nanofilms and its application in improving hydrogen evolution reaction. Proc. Natl Acad. Sci. USA 110, 19701–19706 (2013).

    Article  CAS  Google Scholar 

  43. Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).

    Article  Google Scholar 

  44. Tong, H. et al. Nano-photocatalytic materials: possibilities and challenges. Adv. Mater. 24, 229–251 (2012).

    Article  CAS  Google Scholar 

  45. Sakthivel, S. et al. Enhancement of photocatalytic activity by metal deposition: characterisation and photonic efficiency of Pt, Au and Pd deposited on TiO2 catalyst. Water Res. 38, 3001–3008 (2004).

    Article  CAS  Google Scholar 

  46. Li, H. X. et al. Mesoporous Au/TiO2 nanocomposites with enhanced photocatalytic activity. J. Am. Chem. Soc. 129, 4538–4539 (2007).

    Article  CAS  Google Scholar 

  47. Subramanian, V., Wolf, E. E. & Kamat, P. V. Catalysis with TiO2/gold nanocomposites. Effect of metal particle size on the Fermi level equilibration. J. Am. Chem. Soc. 126, 4943–4950 (2004).

    Article  CAS  Google Scholar 

  48. Bai, H. W., Liu, Z. Y. & Sun, D. D. Hierarchical ZnO/Cu ‘corn-like’ materials with high photodegradation and antibacterial capability under visible light. Phys. Chem. Chem. Phys. 13, 6205–6210 (2011).

    Article  CAS  Google Scholar 

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Acknowledgements

We acknowledge the Stanford facilities, Stanford Nanocharacterization Laboratory and Soft & Hybrid Materials, for characterization. Y.C. acknowledges support from the US Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division, under contract DE-AC02-76SF00515. We thank G. M. Stewart for his help with the schematic drawing.

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Contributions

C.L. and Y.C. developed the concept. C.L. synthesized the samples and conducted the disinfection measurement and material characterizations. D.K. and H.W. helped with the material synthesis. P.-C.H. and S.W. helped with the optical measurement. H.Y. helped with the Kelvin probe measurement. H.-W.L. did the TEM characterization. D.K. helped with the Raman spectroscopy measurement. Y.L. helped with catalyst measurements. P.A.M. helped with estimation of the real-sunlight spectrum. K.M.P. helped with HPLC measurement. C.L., A.B.B. and Y.C. analysed the data and co-wrote the paper. K.Y. and D.L. provided important experimental insights. All the authors discussed the whole paper.

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Correspondence to Yi Cui.

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Liu, C., Kong, D., Hsu, PC. et al. Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light. Nature Nanotech 11, 1098–1104 (2016). https://doi.org/10.1038/nnano.2016.138

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