Facet-specific photoreduction and immobilization of Cr(vi) on hematite nanocrystals

doi:10.1039/d4en00040d

	Chen, Chaorong 1,2,6; Xian, Haiyang 1,2; Liu, Jing 3; Chen, Qingze 1,2; Liang, Xiaoliang1,2 ; Zhu, Runliang1,2 ; Hochella Jr, Michael F.4,5
	Facet-specific photoreduction and immobilization of Cr(vi) on hematite nanocrystals
刊名	ENVIRONMENTAL SCIENCE-NANO
ISSN号	2051-8153
	2024-06-20
卷号	11 期号:8 页码:3510-3521
DOI	10.1039/d4en00040d
语种	英语
WOS研究方向	Chemistry ; Environmental Sciences & Ecology ; Science & Technology - Other Topics
摘要	Photochemical and adsorptive reactions occurring at the mineral-water interface are of great importance in controlling the fate and transport of contaminants in nature, but the effects of the mineral surface structure on the interplay of these two processes and the underlying mechanisms remain largely unknown. In this work, two different structurally well-defined hematite nanocrystals were employed to explore the coupled photoreduction and immobilization of Cr(vi) on various facets of hematite under light irradiation. Compared with hematite quasi-nanocubes (HNCs) exposing only {012} facets, hematite nanoplates (HNPs) with exposed {001} and {113} facets exhibited higher immobilization ability for Cr(vi) under light irradiation, indicating that the coupled process of photoreduction and adsorption of Cr(vi) strongly relied on the particularly exposed facets of hematite. X-ray photoelectron spectroscopy measurements indicated that the removed Cr(vi) from solution was mainly immobilized on hematite surfaces in the form of Cr(iii) (the reduced products of Cr(vi)). Transmission electron microscopy and electron energy-loss spectroscopy results revealed that the accumulation of Cr species was predominantly on the {113} facets of HNPs and the {012} facets of HNCs. Theoretical calculations show that the work function difference between the {113} and {001} facets was directly linked with the effective separation of photogenerated electron-hole pairs in HNPs, which is beneficial for the reduction of Cr(vi). The results of desorption experiments indicate that the coupling of photoreduction and adsorption processes significantly promotes the long-term immobilization of Cr species and effectively reduces their environmental risks (the desorption of Cr(vi) from the HNP and HNC samples decreased from 35.9% and 33.5% to 0.3% and 1.7%, respectively). Overall, the exposed facets can significantly affect the electron transfer properties of hematite as well as the binding affinity for Cr species, thereby governing the reduction and immobilization behavior of Cr(vi) on various facets of hematite. These results advance our understanding of the speciation and immobilization of redox-sensitive contaminants at the surfaces of semiconducting minerals in nature.
WOS记录号	WOS:001261840500001
收录类别	SCI
引用统计	被引频次：4[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.gig.ac.cn/handle/344008/83065
专题	中国科学院矿物学与成矿学重点实验室
作者单位	1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Guangdong Prov Key Lab Mineral Phys & Mat, Guangzhou 510640, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Macau Univ Sci & Technol, State Key Lab Lunar & Planetary Sci, Taipa 999078, Macau, Peoples R China 4.Pacific Northwest Natl Lab, Energy & Environm Directorate, Richland, WA 99354 USA 5.Virginia Tech, Dept Geosci, Blacksburg, VA 24061 USA 6.Xiangtan Univ, Coll Environm & Resources, Dept Environm, Xiangtan 411105, Peoples R China
推荐引用方式 GB/T 7714	Chen, Chaorong,Xian, Haiyang,Liu, Jing,et al. Facet-specific photoreduction and immobilization of Cr(vi) on hematite nanocrystals[J]. ENVIRONMENTAL SCIENCE-NANO,2024,11(8):3510-3521.
APA	Chen, Chaorong.,Xian, Haiyang.,Liu, Jing.,Chen, Qingze.,Liang, Xiaoliang.,...&Hochella Jr, Michael F..(2024).Facet-specific photoreduction and immobilization of Cr(vi) on hematite nanocrystals.ENVIRONMENTAL SCIENCE-NANO,11(8),3510-3521.
MLA	Chen, Chaorong,et al."Facet-specific photoreduction and immobilization of Cr(vi) on hematite nanocrystals".ENVIRONMENTAL SCIENCE-NANO 11.8(2024):3510-3521.