Molecular fractionation and sub-nanoscale distribution of dissolved organic matter on allophane

Ding, Yang1,2; Lu, Yang1,2; Liao, Peng1,2,3; Peng, Shimeng1,2; Liang, Yuzhen1,2; Lin, Zhang1,2; Dang, Zhi1,2; Shi, Zhenqing1,2

2019-07

10.1039/c9en00335e

Environmental Science-Nano   影响因子和分区

2051-8153

2051-8161

Allophane, a nano-size alumino-silicate mineral, has a peculiar hollow and spherical nanostructure with diameters of 3.5-5 nm and some defects or open pores. The adsorptive fractionation of dissolved organic matter (DOM) within allophane nanostructures is a key soil process affecting carbon cycling in soil environments, but the underlying mechanisms are poorly understood. In this study, we employed both double spherical-aberration-corrected scanning transmission electron microscopy (Cs-STEM) and Fouriertransform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to elucidate the spatial distribution of DOM on allophane at sub-nanoscales and the mechanisms controlling the adsorptive fractionation of DOM molecules. Copper titration experiments and WHAM 7 were used to assess the role of carboxylic groups in the fractionation of DOM on allophane. Cs-STEM results revealed that within allophane aggregates, C mainly distributed on the edges of the pore spaces between allophane aggregates while some DOM molecules localized at some small pore spaces. Moreover, the Cs-STEM results suggested that DOM molecules were able to enter the interior spaces within tiny allophane nanoparticles/aggregates. FT-ICRMS analysis indicated that molecules with high aromaticity, oxygen numbers and amounts of COO groups were preferentially adsorbed. The results of Cu titration and WHAM 7 calculations indicated that the carboxylic functional groups of DOM were selectively removed from solutions during adsorptive fractionation. Overall, both chemical adsorption and physical isolation may be responsible for the strong sequestration of DOM molecules on allophane. Our results contribute to prediction of C cycling in the environment.

SCI ; EI

英语

其他

Basic Research Project of Shenzhen[JCYJ20170307110055182]

Chemistry ; Environmental Sciences & Ecology ; Science & Technology - Other Topics

Chemistry, Multidisciplinary ; Environmental Sciences ; Nanoscience & Nanotechnology

WOS:000475481100023

ROYAL SOC CHEMISTRY

20192907207626

Aberrations ; Aggregates ; Aspherics ; Biogeochemistry ; Biological materials ; High resolution transmission electron microscopy ; Mass spectrometry ; Molecules ; Nanostructures ; Organic compounds ; Scanning electron microscopy ; Silicate minerals ; Titration

Highway Engineering:406 ; Biological Materials and Tissue Engineering:461.2 ; Minerals:482.2 ; Light/Optics:741.1 ; Optical Devices and Systems:741.3 ; Nanotechnology:761 ; Chemistry:801 ; Biochemistry:801.2 ; Organic Compounds:804.1 ; Atomic and Molecular Physics:931.3 ; Solid State Physics:933

Web of Science

1.South China Univ Technol, Sch Environm & Energy, Guangzhou 510006, Guangdong, Peoples R China
2.South China Univ Technol, Key Lab Pollut Control & Ecosyst Restorat Ind Clu, Minist Educ, Guangzhou 510006, Guangdong, Peoples R China
3.Southern Univ Sci & Technol, Sch Environm Sci & Engn, Guangdong Prov Key Lab Soil & Groundwater Pollut, Shenzhen 518055, Peoples R China

Ding, Yang,Lu, Yang,Liao, Peng,et al. Molecular fractionation and sub-nanoscale distribution of dissolved organic matter on allophane[J]. Environmental Science-Nano,2019,6(7):2037-2048.

Ding, Yang.,Lu, Yang.,Liao, Peng.,Peng, Shimeng.,Liang, Yuzhen.,...&Shi, Zhenqing.(2019).Molecular fractionation and sub-nanoscale distribution of dissolved organic matter on allophane.Environmental Science-Nano,6(7),2037-2048.

Ding, Yang,et al."Molecular fractionation and sub-nanoscale distribution of dissolved organic matter on allophane".Environmental Science-Nano 6.7(2019):2037-2048.