TY - JOUR
T1 - Environmentally friendly synthesis of flexible MOFs M(NA)2 (M = Zn, Co, Cu, Cd) with large and regenerable ammonia capacity
AU - Chen, Yang
AU - Shan, Bohan
AU - Yang, Chengyin
AU - Yang, Jiangfeng
AU - Li, Jinping
AU - Mu, Bin
N1 - Funding Information:
We express great gratitude to the National Natural Science Foundation of China (No. 21676175), the Graduate Education Innovation Project of Shanxi Province (No. 2017BY051), and the State Scholarship Fund from China Scholarship Council (No. 201706930002).
PY - 2018
Y1 - 2018
N2 - Two environmentally friendly and efficient synthesis methods, NH3-assisted synthesis and solvent-evaporated conversion, have been developed for the synthesis of a series of M(NA)2 (M = Zn, Co, Cu, Cd; NA = nicotinate) flexible MOFs. The two-dimensional M(NA)2 (M = Zn, Co) and three-dimensional M(NA)2 (M = Cu, Cd) materials exhibit peculiar structural transformation. These frameworks can be obtained from dehydration of M(NA)2(H2O)4 (M = Zn, Co, Cu, Cd) which are zero-dimensional supramolecular structures. Interestingly, the structural transformation of M(NA)2 (M = Zn, Co, Cd) is reversible after liquid water adsorption. Due to the flexible structure of these MOFs, they exhibit abnormal NH3 adsorption properties. The two-dimensional Zn(NA)2 shows a gate-opening behavior for NH3 adsorption. Its layers opened at a pressure of 0.22 bar in the first cycle, resulting in a two-step NH3 uptake with a capacity of 10.2 mmol g-1 at 1 bar. The gate-opening pressure shifted to a lower value with cycles. Co(NA)2 has a huge NH3 uptake of 17.5 mmol g-1, which is top-ranking among the reported values. For the NH3 adsorption over Cu(NA)2 and Cd(NA)2, the adsorption rates increase and adsorption equilibrium is achieved faster after three cycles. Their maximum capacity at 1 bar is 13.4 and 6 mmol g-1, respectively. More importantly, all MOFs can be regenerated under vacuum and heating conditions of 150 °C for 70 min, and they all retained the capacity. The advantages of environmentally friendly synthesis, large adsorption capacity, and regenerable properties indicate that M(NA)2 (M = Zn, Co, Cu) are promising candidates for NH3 adsorption.
AB - Two environmentally friendly and efficient synthesis methods, NH3-assisted synthesis and solvent-evaporated conversion, have been developed for the synthesis of a series of M(NA)2 (M = Zn, Co, Cu, Cd; NA = nicotinate) flexible MOFs. The two-dimensional M(NA)2 (M = Zn, Co) and three-dimensional M(NA)2 (M = Cu, Cd) materials exhibit peculiar structural transformation. These frameworks can be obtained from dehydration of M(NA)2(H2O)4 (M = Zn, Co, Cu, Cd) which are zero-dimensional supramolecular structures. Interestingly, the structural transformation of M(NA)2 (M = Zn, Co, Cd) is reversible after liquid water adsorption. Due to the flexible structure of these MOFs, they exhibit abnormal NH3 adsorption properties. The two-dimensional Zn(NA)2 shows a gate-opening behavior for NH3 adsorption. Its layers opened at a pressure of 0.22 bar in the first cycle, resulting in a two-step NH3 uptake with a capacity of 10.2 mmol g-1 at 1 bar. The gate-opening pressure shifted to a lower value with cycles. Co(NA)2 has a huge NH3 uptake of 17.5 mmol g-1, which is top-ranking among the reported values. For the NH3 adsorption over Cu(NA)2 and Cd(NA)2, the adsorption rates increase and adsorption equilibrium is achieved faster after three cycles. Their maximum capacity at 1 bar is 13.4 and 6 mmol g-1, respectively. More importantly, all MOFs can be regenerated under vacuum and heating conditions of 150 °C for 70 min, and they all retained the capacity. The advantages of environmentally friendly synthesis, large adsorption capacity, and regenerable properties indicate that M(NA)2 (M = Zn, Co, Cu) are promising candidates for NH3 adsorption.
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U2 - 10.1039/c8ta02845a
DO - 10.1039/c8ta02845a
M3 - Article
AN - SCOPUS:85047875079
SN - 2050-7488
VL - 6
SP - 9922
EP - 9929
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 21
ER -