Threefold growth efficiency improvement of silica nanosprings by using silica nanosprings as a substrate

The growth efficiency of one-dimension (1D) nanostructures via the vapor-liquid-solid process is commonly attributed to parameters such as precursor vapor pressure, substrate temperature, and the choice of the catalyst. The work presented herein is an investigation of the use of silica nanosprings (SNs) as a 3D substrate for improving the growth efficiency of SN themselves. SNs are a 1D nanomaterial that form a nonwoven structure with optimal geometric characteristics and surface properties that mitigate collisions between growing nanosprings and ripening of the gold catalyst, which should improve SN yield. Nanospring growth, for an eight hour period, on an SN coated surface relative to an equivalent flat substrate increased from ≈25 mgh^-1 to ≈80 mgh^-1, respectively. All things being equal, by splitting the typical amount of catalyst, in this case gold, between the first and second growth, the double growth procedure produced more than three times more nanosprings than the equivalent single growth of a SN. In addition, using an SN as a substrate increased the sustained growth condition from four to eight hours, and thus increased by a factor of ten the gravimetric yield of SNs relative to the mass of gold used.