A novel strategy for the efficient decomposition of toxic sodium cyanate by hematite

Dong, Kaiwei; Xie, Feng; Chang, Yuqing; Chen, Chunlin; Wang, Wei; Lu, Diankun; Gu, Xiaowei

doi:10.1016/j.chemosphere.2020.127047

Cited by 8 publications

(2 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1−5 Abundant iron-bearing minerals in soils and sediments significantly affect the migration and fate of arsenic. 6,7 Hematite (α-Fe 2 O 3 ) is one of the most common iron oxides that is widely distributed in tropical and subtropical regions. Due to its thermodynamic stability and high reactivity, hematite extensively participates in biogeochemical processes (e.g., via adsorption, oxidation/reduction, and catalytic processes) that have attracted much attention.…”

Section: Introductionmentioning

confidence: 99%

“…Arsenic (As) is a metalloid commonly found in polluted soils and groundwaters that has high toxicity and carcinogenicity, which might increase incidences of cancer, along with other negative health effects. Moreover, the migration of arsenic in the environment further increases its environmental risks. − Abundant iron-bearing minerals in soils and sediments significantly affect the migration and fate of arsenic. , Hematite (α-Fe 2 O 3 ) is one of the most common iron oxides that is widely distributed in tropical and subtropical regions. Due to its thermodynamic stability and high reactivity, hematite extensively participates in biogeochemical processes (e.g., via adsorption, oxidation/reduction, and catalytic processes) that have attracted much attention. − However, hematite hardly exists in perfectly crystalline form in natural environments due to the incorporation of impurities (e.g., Al and Mn ions) and the dynamic changes of environmental conditions (e.g., temperature), including redox conditions (e.g., via flooding and drainage), − which allows hematite to possess different vacancy defects, thereby showing varying physical and chemical properties.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quantitative Contribution of Oxygen Vacancy Defects to Arsenate Immobilization on Hematite

Xiang

Chen

et al. 2023

Environ. Sci. Technol.

View full text Add to dashboard Cite

Hematite is a common iron oxide in natural environments, which has been observed to influence the transport and fate of arsenate by its association with hematite. Although oxygen vacancies were demonstrated to exist in hematite, their contributions to the arsenate immobilization have not been quantified. In this study, hematite samples with tunable oxygen vacancy defect (OVD) concentrations were synthesized by treating defect-free hematite using different NaBH 4 solutions. The vacancy defects were characterized by positron annihilation lifetime spectroscopy, Doppler broadening of annihilation radiation, extended X-ray absorption fine structure (EXAFS), thermogravimetric mass spectrometry (TG-MS), electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS). The results revealed that oxygen vacancy was the primary defect type existing on the hematite surface. TG-MS combined with EPR analysis allowed quantification of OVD concentrations in hematite. Batch experiments revealed that OVDs had a positive effect on arsenate adsorption, which could be quantitatively described by a linear relationship between the OVD concentration (C def , mmol m −2 ) and the enhanced arsenate adsorption amount caused by defects (ΔQ m , μmol m −2 ) (ΔQ m = 20.94 C def , R 2 = 0.9813). NH 3diffuse reflectance infrared Fourier transform (NH 3 -DRIFT) analysis and density functional theory (DFT) calculations demonstrated that OVDs in hematite were beneficial to the improvement in adsorption strength of surface-active sites, thus considerably promoting the immobilization of arsenate.

show abstract

Section: Introductionmentioning

confidence: 99%