Vapor-phase preparation of gold nanocrystals by chloroauric acid pyrolysis

[Display omitted] •A facile method to prepare high quality gold nanocrystals by HAuCl4 pyrolysis.•The growth mechanism of the gold nanocrystals was systemically investigated.•The gold nanocrystals show excellent plasmonic properties for SERS. We report that gold nanocrystals can be prepared from vapor phase using chloroauric acid (HAuCl4) as the precursor. By tuning the vapor-phase deposition parameters, the size and space distribution of the gold nanocrystals can be well controlled on substrates. Systematic control experiments demonstrate that intermediate AuCl and AuCl3 products pyrolyzed from HAuCl4 play an essential role in this vapor-phase deposition process. Compared to conventional wet-chemical synthesis process, vapor-phase process enables direct deposition of gold nanoparticles on solid substrates with better coverage and uniformity, which may find applications in surface-enhanced Raman scattering and plasmon-enhanced photocatalysis.