Enhanced Water Adsorption Performance of UiO-66 Modulated with p-Nitrobenzoic or p-Hydroxybenzoic Acid: Introduced Defects and Functional Groups

Guodong Fu; Ping Wu; Jinguang Yang; Shiping Zhang; Li Wang; Min Xu; Xiulan Huai

doi:10.1021/acs.inorgchem.2c01543

Enhanced Water Adsorption Performance of UiO-66 Modulated with p-Nitrobenzoic or p-Hydroxybenzoic Acid: Introduced Defects and Functional Groups

Inorg Chem. 2022 Nov 14;61(45):17943-17950. doi: 10.1021/acs.inorgchem.2c01543. Epub 2022 Nov 1.

Authors

Guodong Fu¹, Ping Wu¹, Jinguang Yang¹, Shiping Zhang¹, Li Wang², Min Xu³, Xiulan Huai³

Affiliations

¹ Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing100083, China.
² Beijing Engineering Research Centre of Energy Saving and Environmental Protection, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing100083, China.
³ Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing100190, China.

PMID: 36318203
DOI: 10.1021/acs.inorgchem.2c01543

Abstract

Adding appropriate modulators can effectively improve the porosity and adsorption performance of UiO-66. Herein, UiO-66 samples were synthesized with p-nitrobenzoic acid (PNBA) and p-hydroxybenzoic acid (PHBA) as modulators. All samples exhibited good crystallinity and thermal stability. The polar functional groups (-NO₂ and -OH) and defects were introduced into UiO-66, which significantly improved its water adsorption performance and applications in adsorption heat transformation. With the addition of six equiv PNBA, the saturated water uptake of UiO-66 increased from 0.40 to 0.58 g/g. Also, 4eqPNBA-UiO-66 exhibited the highest water uptake under low relative pressure, which was almost twice that of "low-defect" LD-UiO-66. The addition of PHBA had little effect on the saturated water absorption. However, its highest water uptake at P/P₀ = 0.3 is 0.23 g/g, which is equivalent to that of 4eqPNBA-UiO-66. Ten consecutive adsorption/desorption cycles indicated that these samples had good cycle stability.