New route to clean wastewater


  • Self-propelling nanomotors, just 200 nanometre in size, could be used for wastewater management in chemical industries. Developed by researchers from Indian Institute of Science Education and Research, Kolkata, and The Institute of Mathematical Sciences, Chennai, the nanomotor can be used for transporting catalysts needed in harsh chemical environments and removing unwanted chemicals in water.


  • Nanorods (rod shaped nanomotors) are made using ammonium heptamolybdate tetrahydrate and dispersed in the solution to be treated.
  • When hydrazine sulphate is added to water, it reacts with the nanorods producing nitrogen gas.
  • This leads to an osmotic stress in the fluid and causes the nanorods to move along the direction of the gas evolved.


  • Molybdenum based soft-oxometalates are non-toxic and easy to synthesize.
  • The complementary charge interactions on the surface trigger their motion.
  • The speed can be increased by increasing the concentration of the fuel hydrazine on the surface of the nanorods and they were found to remain in their motile state for about three days.


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