Dissolved organic matter-mediated reduction of ionic Au(Ⅲ) to elemental Au nanoparticles and their growth to visible granules

作者：Ying Chen; Yingying Guo; Guangliang Liu; Maoyong Song; Yong Cai; Yongguang Yin^*

来源：Chinese Chemical Letters, 2020, 31(07): 1970-1973.

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 100 μm) 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.

• 单位
  中国科学院大学; 环境化学与生态毒理学国家重点实验室