LAUSR

The friction between nanomaterials and Teflon magnetic stirring rods has recently drawn much attention for its role in dye degradation by magnetic stirring in dark. Presently the friction between TiO 2 nanoparticles and magnetic stirring rods in water has been deliberately enhanced and explored. As much as 1.00 g TiO 2 nanoparticles were dispersed in 50 mL water in 100 mL quartz glass reactor, which got gas-closed with about 50 mL air and a Teflon magnetic stirring rod in it. The suspension in the reactor was magnetically stirred in dark. Flammable gases of 22.00 ppm CO, 2.45 ppm CH 4 , and 0.75 ppm H 2 were surprisingly observed after 50 h of magnetic stirring. For reference, only 1.78 ppm CO, 2.17 ppm CH 4 , and 0.33 ppm H 2 were obtained after the same time of magnetic stirring without TiO 2 nanoparticles. Four magnetic stirring rods were simultaneously employed to further enhance the stirring, and as much as 30.04 ppm CO, 2.61 ppm CH 4 , and 8.98 ppm H 2 were produced after 50 h of magnetic stirring. A mechanism for the catalytic role of TiO 2 nanoparticles in producing the flammable gases is established, in which mechanical energy is absorbed through friction by TiO 2 nanoparticles and converted into chemical energy for the reduction of CO 2 and H 2 O. This finding clearly demonstrates a great potential for nanostructured semiconductors to utilize mechanical energy through friction for the production of flammable gases.