Ultrathin gamma-Al2O3 nanofibers with large specific surface area and their enhanced thermal stability by Si-doping

摘要

A series of ultrathin boehmite nanofibers with large specific surface area (302-385 m(2) g(-1)) were synthesized via a parallel flow co-precipitation method using cheap NaAlO2 and Al-2(SO4)(3) as reactive agents and then transformed into gamma-Al2O3 by calcination at 500 degrees C. The resultant gamma-Al2O3 possesses similar nanofibrous morphology with a length of over 100 nm and a transverse size of similar to 2 nm, large specific surface area of up to 419 m(2) g(-1) and relatively high thermal stability, and still retain a specific surface area of 132, 104 and 70 m(2) g(-1) after being calcined at 1000, 1100 and 1200 degrees C, respectively. Moreover, the thermal stability could be further improved by doping Si for inhibiting the phase transformation and the specific surface area of Si-doped gamma-Al2O3 nanofibers could be up to 113 m(2) g(-1) at 1200 degrees C.