Designing heterogeneous MOF-on-MOF membrane with hierarchical pores for effective water treatment

MOFs meet membrane: application in water treatment and separation

“…In addition to the composite of structurally similar MOF materials, some composite membranes of MOF materials with completely different structures have been prepared. 136 Inspired by this, Xu et al designed a heterogeneous layered UiO-66-NH 2 @ZIF-8 membrane 137 using a simple layer-by-layer assembly method. The UiO-66-NH 2 @ZIF-8 membrane retained the large pores of the UiO-66-NH 2 material and the molecular-sieving pores of ZIF-8, which promoted the transport of water and intercepted the dye with a >97% dye removal rate.…”

Isolation of Sensing Units and Adsorption Groups Based on MOF-on-MOF Hierarchical Structure for Both Highly Sensitive Detection and Removal of Hg2+

“…The characteristic peaks of ZIF-8 were at 7.33, 10.45, 12.78, 14.75, 16.49, and 18.11°, corresponding to the (011), (002), ( 112), ( 022), (013), and (222) crystal planes, respectively; these results were consistent with previous reports. 26,27 For the prepared UiO-66-NH 2 @ AuNCs/ZIF-8, the characteristic peaks of UiO-66-NH 2 , AuNCs, and ZIF-8 were all observed, although weak. The weakening of the UiO-66-NH 2 peaks could be attributed to the effect of the covering AuNCs/ZIF-8 layer on UiO-66-NH 2 , while the weakening of the ZIF-8 peaks originated from the formation of amorphous structures due to the competition of AuNCs and the N atom of 2-MIM for Zn 2+ .…”

“…The weakening of the UiO-66-NH 2 peaks could be attributed to the effect of the covering AuNCs/ZIF-8 layer on UiO-66-NH 2 , while the weakening of the ZIF-8 peaks originated from the formation of amorphous structures due to the competition of AuNCs and the N atom of 2-MIM for Zn 2+ . 27,28 The N 2 adsorption−desorption isotherms of UiO-66-NH 2 , ZIF-8, UiO-66-NH 2 @ZIF-8, and UiO-66-NH 2 @AuNCs/ZIF-8 displayed type I hysteresis loops and microporous structures (Figure 1H). Compared with pure UiO-66-NH 2 (1559.19 m 2 • g −1 ) and ZIF-8 (1757.07 m 2 •g −1 ), the Brunauer−Emmett− Teller (BET) surface area of UiO-66-NH 2 @ZIF-8 was decreased to 1083.02 m 2 •g −1 ; this was attributed to the agglomeration of ZIF-8 on the UiO-66-NH 2 surface.…”

Robust MOF-on-MOF heterostructures as efficient cathode candidates for next-generation supercapacitors

“…, one of the MOFs can provide high surface area, and the other can provide higher conductivity, (iv) their low-cost and environment-friendly nature helps bulk production for commercial use, and (v) the robust nature of the MOF structure makes them stable. So far, MOF-on-MOF architectures have been utilized for various applications like catalysis, separation, sensing, water treatment, pesticide removal, and oxygen evolution reaction 50–53 However, the application of MOF-on-MOF in supercapacitors is still in the initial stages of development and requires attention to improving the performance and stability.…”

“…There are several advantages to using MOF-on-MOF structures, such as 48,49 (i) higher energy density and power density, (ii) versatility with MOF selection and functionalization, (iii) various MOFs can be used to customize structures with tailored properties, leading to optimized energy storage performance, i.e., one of the MOFs can provide high surface area, and the other can provide higher conductivity, (iv) their low-cost and environment-friendly nature helps bulk production for commercial use, and (v) the robust nature of the MOF structure makes them stable. So far, MOF-on-MOF architectures have been utilized for various applications like catalysis, separation, sensing, water treatment, pesticide removal, and oxygen evolution reaction [50][51][52][53] However, the application of MOF-on-MOF in supercapacitors is still in the initial stages of development and requires attention to improving the performance and stability.…”