Agar Aerogel Containing Small-Sized Zeolitic Imidazolate Framework Loaded Carbon Nitride: A Solar-Triggered Regenerable Decontaminant for Convenient and Enhanced Water Purification

Abstract

Although ZIF-based adsorbents are promising for environmental remediation, their performance is limited by their large crystal size, intrinsic fragility, and poor processability and reusability. To this end, in this work, highly dispersed and small sized (14.95 nm) metal−organic frameworks (MOFs), via the restriction of overgrowth and agglomeration on carbon nitride (C 3 N 4 ) nanosheets, are integrated into agar aerogel, forming a flexible and efficient aerogel absorbent with photocatalytic activity. This separationfree hybrid aerogel mantaining the crystal structure of zeolitic imidazolate framework (ZIF-8) with smaller size exhibits a 1.44 times greater adsorption capacity for dye than that of pristine bulk ZIF-8. Most importantly, the introduction of C 3 N 4 nanosheets not only regulates the growth of ZIF-8 crystals but also enables the hybdrid aerogel with stable reusability throughout five consecutive adsorption−degradation cycles, obtained via solar irradiation. This ecofriendly, regeneration technology provides a convenient and sustainable approach to reduce the cost and eliminate the use of hazardous substances for environmental remediation. Dramatically, for practical use under sunlight, attributed to the photocatalysis effect of the uniquely designed adsorbent, the active adsorption sites of the aerogel are continuously provided, resulting in enhanced dye removal ability. Therefore, this work establishes an innovative, low-cost, convenient, solar-triggered, sustainable solution for the management of water contamination by a MOF-based aerogel decontaminant.

Regeneration of Used Frying Oils by Selected Metal–Organic Frameworks as Adsorbents

“…In another study (Vlasova et al, ), MIL‐53 (Al), Zn‐MOF, and MIL‐125 (Ti) MOF were used to refine crude vegetable oils, and shown that the MOF pose great ability to selectively adsorb and remove FFA, peroxides, and color pigments from the oils. In two recent studies (Yang et al, ; Zhang et al, ), some food dyes were selectively removed from aqueous solution by MOF, indicating the potential of MOF application for the selective adsorption of chemicals from liquids.…”

A Review on Revolutionary Natural Biopolymer-Based Aerogels for Antibacterial Delivery

“…Aerogel have been also fabricated from other biopolymers such as pectin [ 62 ], starch [ 63 ], carrageenan [ 64 ], agar [ 65 ], and xanthan [ 10 , 66 ]. Nešić et al fabricated environmentally friendly pectin-based aerogel using TiO 2 as an antibacterial agent.…”

Carbon Aerogels for Environmental Clean‐Up

“…Carbon aerogels are widely used in heavy metal adsorption because of their porous structure, large specific surface area, high porosity and, most importantly, controllable surface functional groups , , . In earlier times, Meena et al investigated the adsorption of seven kinds of heavy metals (Cd, Pb, Hg, Cu, Ni, Mn and Zn) using carbon aerogel (carbonized from resorcinol formaldehyde (RF) aerogel).…”

“…Therefore, their application for environmental clean‐up has grown rapidly and drawn significant scientific interest . Up to now, carbon aerogels have been used in lots of the remediation processes based on their adsorption and catalysis properties, like oil/water separation,, , removal of heavy metal ions,, clean‐up of volatile organic compounds (VOCs), CO 2 capture,, removal of nitrogen oxide (NO x ) and so on (Figure ).…”