The biogeochemical transformation of gold(Au),i.e.its dissolution and re-precipitation,is critical in supergene transport of Au and formation of Au granules.Besides biogenic reduction,the formation Au granules can als...The biogeochemical transformation of gold(Au),i.e.its dissolution and re-precipitation,is critical in supergene transport of Au and formation of Au granules.Besides biogenic reduction,the formation Au granules can also be driven by chemical processes.Previous studies have showed the fo rmation of Au nanoparticles(AuNPs)from ionic Au(Ⅲ)can be mediated by dissolved organic matter under sunlight.In this letter,we further demonstrated that these AuNPs can further slowly(in years)grow into visible Au granules.Different sized nano-flower and fractal dendrite-like branched gold structures(from tens of nanometres to over 100μm)were observed in the Au granule sample.This growth of AuNPs into visible Au granules may play a critical role in the supergene mineralization and enrichment of secondary Au and drive the biogeochemical cycle of Au.展开更多
基金the National Natural Science Foundation of China(No.21777178)Key Projects for Frontier Sciences ofthe Chinese Academy of Sciences(No.QYZDB-SSWDQC018)+2 种基金the CAS Interdisciplinary Innovation Team(No.JCTD-2018-04)supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2016037)。
文摘The biogeochemical transformation of gold(Au),i.e.its dissolution and re-precipitation,is critical in supergene transport of Au and formation of Au granules.Besides biogenic reduction,the formation Au granules can also be driven by chemical processes.Previous studies have showed the fo rmation of Au nanoparticles(AuNPs)from ionic Au(Ⅲ)can be mediated by dissolved organic matter under sunlight.In this letter,we further demonstrated that these AuNPs can further slowly(in years)grow into visible Au granules.Different sized nano-flower and fractal dendrite-like branched gold structures(from tens of nanometres to over 100μm)were observed in the Au granule sample.This growth of AuNPs into visible Au granules may play a critical role in the supergene mineralization and enrichment of secondary Au and drive the biogeochemical cycle of Au.
