The impact of redox annealing on intrinsic properties and fluoride adsorption performance of CeO2 nanomaterials

Pan，Yu1; Liu，Xun1,2; Zhang，Meng1; Han，Qi1; Shu，Yufei1; Wang，Mengxia1,2; Liu，Bei1; Wang，Zhongying1

2023-11-15

10.1016/j.cej.2023.146347

Chemical Engineering Journal   影响因子和分区

1385-8947

1873-3212

The presence of excess fluoride ions in drinking water has raised widespread concerns, necessitating the development of effective methods for its removal. Cerium dioxide (CeO) holds promise as a selective adsorbent for fluoride ions, due to its exceptional affinity for fluoride and stability across a wide pH range. However, the impact of intrinsic properties of CeO on its adsorption characteristics and mechanisms remains unclear. In this study, we prepared a range of CeO materials with diverse intrinsic properties by adjusting the annealing temperature and atmosphere. Through a series of characterization techniques, we discovered a correlation between the content of oxygen vacancies, Ce(III) species, and surface hydroxyl groups (–OH), all of which decreased simultaneously with increasing air annealing temperature. With respect to the adsorption performance, the highest fluoride adsorption capacity of 111.1 mg g was observed in un-CeO, representing the nanomaterials with the highest oxygen vacancies. This capacity gradually decreased to 29.1 mg g in 800-CeO. Following fluoride adsorption, the oxygen vacancy density, Ce(III) content, and surface –OH content of all CeO materials decreased. When CeO materials were annealed in H for 1 h, the F adsorption density increased due to the formation of more oxygen vacancies and surface –OH. Based on our findings, we conclude that oxygen vacancies play a critical role in determining whether fluoride ions can successfully exchange with surface –OH groups and enter the crystal lattice of CeO, which significantly affects the adsorption performance. The pivotal role of oxygen vacancies, as proposed in this study, provides a valuable direction for future research aimed at enhancing the fluoride adsorption performance of CeO.

Cerium dioxide Fluoride removal Hydroxyl group Oxygen vacancies Redox annealing

SCI ; EI

英语

第一 ; 通讯

National Natural Science Foundation of China[22076075]

Engineering

Engineering, Environmental ; Engineering, Chemical

WOS:001094385700001

ELSEVIER SCIENCE SA

20234214882556

Adsorption ; Cerium oxide ; Fluorine compounds ; Ions ; Nanostructured materials ; Oxygen vacancies ; Potable water

Water Resources:444 ; Heat Treatment Processes:537.1 ; Nanotechnology:761 ; Chemical Operations:802.3 ; Inorganic Compounds:804.2 ; Crystalline Solids:933.1

ENGINEERING

2-s2.0-85173678991

Scopus

1.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.School of Environment,Harbin Institute of Technology,China

Pan，Yu,Liu，Xun,Zhang，Meng,et al. The impact of redox annealing on intrinsic properties and fluoride adsorption performance of CeO2 nanomaterials[J]. Chemical Engineering Journal,2023,476.

Pan，Yu.,Liu，Xun.,Zhang，Meng.,Han，Qi.,Shu，Yufei.,...&Wang，Zhongying.(2023).The impact of redox annealing on intrinsic properties and fluoride adsorption performance of CeO2 nanomaterials.Chemical Engineering Journal,476.

Pan，Yu,et al."The impact of redox annealing on intrinsic properties and fluoride adsorption performance of CeO2 nanomaterials".Chemical Engineering Journal 476(2023).