Ni(NO3)2-Assisted Catalytic Synthesis and Photoluminescence Property of Ultralong Single Crystal Sialon Nanobelts

Ultralong single crystal Sialon nanobelts were prepared on a graphite cover coated with Ni(NO3)2 by facile thermal chemical vapor deposition reactions of Si, Al, and Al2O3 with flowing N2 at 1450 °C. The as-synthesized Sialon nanobelts were up to several millimeters long and several hundred nanometers wide, and they had width/thickness ratios of 5–15. Their growth process was codominated by a Ni-catalytic vapor–liquid–solid (VLS) base-growth mechanism and a vapor–solid (VS) tip-growth mechanism. The former was responsible for the initial nucleation and proto-nanobelt formation of Sialon and the subsequent growth along the [100] direction, and the latter additionally contributed the growth at tips. The room-temperature photoluminescence (PL) spectrum showed that the as-synthesized Sialon nanobelts had a special emission with two maximum peaks at 409 nm (3.03 eV) and 428 nm (2.90 eV) located in the violet-blue spectral range, making possible potential applications in LED and optoelectronic nanodevices.