Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Liu, Xin1,2; Liu, Huan1,2; Zong, Meirong1; Chen, Meng3 ; He, Hongping3,4; Wang, Rucheng1; Lu, Xiancai1,2,5
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| Mn substitution and distribution in goethite and influences on its photocatalytic properties: A combined study using first-principles calculations and photocatalytic experiments | |
| Source Publication | AMERICAN MINERALOGIST
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| ISSN | 0003-004X |
| 2023-05-25 | |
| Volume | 108Issue:5Pages:968-977 |
| DOI | 10.2138/am-2022-8182 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics ; Mineralogy |
| Abstract | Goethite and modified goethites have been found as good photocatalysts because their conduction band can mediate electron transfer in various redox processes. Many kinds of metal elements can be incorporated into the structure of goethite to form solid solutions in nature, but their optoelectronic properties have not been well disclosed. Mn-substituted goethite is one of the potential photocatalysts, which can exhibit high-photocatalytic activity in many Earth's surface processes. Based on the first-principles calculation, pairwise interaction energies and static lattice energies of goethitegroutite solid solution were computed, and the most thermodynamically stable configurations of Mn-substituted goethite were determined. The results indicate that Mn3+ ion tends to distribute within the cation layer parallel to the (001) plane. Phase relations of goethite-groutite solid solution were derived by subsequent configurational statistics with energies of all 2(32) configurations of a 2 x 1 x 4 supercell with 32 exchangeable cations. The phase diagram shows that no more than 3 mol% Fe of goethite can be substituted by Mn ions. Therefore, Mn-substituted goethite is thermodynamically metastable or bears groutite-like clusters/lamellae. Furthermore, the effects of Mn substitutions on the band gap were experimentally and theoretically investigated. It is found that a small amount of Mn-substitution can reduce the band gap of goethite significantly, and the decrease ceases when the Mn content is higher than 3-4 mol%. Such a decrease in band gap causes red-shift to the photo response wavelength of goethite and improves the responding capability. This improvement was confirmed in the experiments of photocatalytic degradation of methylene blue (MB). Such kind of photocatalytic reaction probably can happen widely in natural environments. Therefore, the contribution of photocatalysis of natural goethites to geochemical processes on Earth's surface should be considered. |
| Keyword | Goethite Mn substitution solid solution band gap photocatalytic property first-principles calculation |
| WOS ID | WOS:000989025200014 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/74351 |
| Collection | 中国科学院矿物学与成矿学重点实验室 |
| Corresponding Author | Lu, Xiancai |
| Affiliation | 1.Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposits Res, Nanjing 210023, Peoples R China 2.Nanjing Univ, Frontiers Sci Ctr Crit Earth Mat Cycling, Nanjing 210023, Peoples R China 3.Chinese Acad Sci, Inst Earth Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny,Guangdong Prov K, Guangzhou 510640, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 5.Nanjing Univ, Sch Earth Sci & Engn, Key Lab Surficial Geochem, Minist Educ, Nanjing 210023, Peoples R China |
| Recommended Citation GB/T 7714 | Liu, Xin,Liu, Huan,Zong, Meirong,et al. Mn substitution and distribution in goethite and influences on its photocatalytic properties: A combined study using first-principles calculations and photocatalytic experiments[J]. AMERICAN MINERALOGIST,2023,108(5):968-977. |
| APA | Liu, Xin.,Liu, Huan.,Zong, Meirong.,Chen, Meng.,He, Hongping.,...&Lu, Xiancai.(2023).Mn substitution and distribution in goethite and influences on its photocatalytic properties: A combined study using first-principles calculations and photocatalytic experiments.AMERICAN MINERALOGIST,108(5),968-977. |
| MLA | Liu, Xin,et al."Mn substitution and distribution in goethite and influences on its photocatalytic properties: A combined study using first-principles calculations and photocatalytic experiments".AMERICAN MINERALOGIST 108.5(2023):968-977. |
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