Defective Metal-Organic Frameworks Incorporating Iridium-Based Metalloligands: Sorption and Dye Degradation Properties.
Artificial control and engineering of metal-organic framework (MOF) crystals with defects can endow them with suitable properties for applications in gas storage, separation, and catalysis. A series of defective iridium-containing MOFs, [Zn4(μ4-O)(Ir-A)2(1-x)(Ir-B)2x] (ZnIr-MOF-dx), were synthesized by doping heterostructured linker Ir-BH3into the parent [Zn4(μ4-O)(Ir-A)2] (ZnIr-MOF), in which Ir-AH3represents [Ir(ppy-COOH)3] (ppyCOOH=3-(pyridin-2-yl)benzoic acid) and Ir-BH3is [Ir(ppy-COOH)2(2-pyPO3H)] (2-pyPO3H2=2-pyridylphosphonic acid). Samples with different degrees of defects were characterized by SEM, IR and NMR spectroscopy, powder XRD measurements, and thermal and elemental analyses. ZnIr-MOF-d0.3was selected as a representative for gas (N2, CO2) or vapor (H2O, alcohol) sorption studies. The results demonstrate that defective ZnIr-MOF-d0.3possesses multiple pore size distributions, ranging from micro- to mesopores, unlike the parent material, which shows a uniform micropore distribution. The hydrophilicity of the interior surface is also increased after defect engineering. As a result, ZnIr-MOF-d0.3shows an enhanced adsorption capability toward n-butanol, relative to that of the parent compound. Optical studies reveal that both ZnIr-MOF and ZnIr-MOF-d0.3have low band gaps (2.35 and 2.40 eV), corresponding to semiconductors. ZnIr-MOF-d0.3exhibits dramatically increased photocatalytic efficiency for dye degradation.
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Kun
K
Fan
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Wei-Xuan
WX
Nie
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Lu-Ping
LP
Wang
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Chwen-Haw
CH
Liao
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Song-Song
SS
Bao
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P.R. China.
Li-Min
http://orcid.org/0000-0003-4437-1105
LM
Zheng
adsorption; defect engineering; dyes/pigments; iridium; metal-organic frameworks