Quick formation of single-crystal nanocubes of silver through dual functions of hydrogen gas in polyol synthesis

High yields of 40-nm silver nanocubes were produced in 20 min by bubbling hydrogen gas through a conventional polyol synthesis. Hydrogen gas both accelerated the reduction rate and generated nitric acid in situ. Twinned seeds were selectively dissolved by balancing the reduction rate with etching by nitric acid, so that only single crystals were produced.