Tuning Hydrophilicity of Aluminum MOFs by a Mixed‐Linker Strategy for Enhanced Performance in Water Adsorption‐Driven Heat Allocation Application

Abstract

Water adsorption-driven heat transfer (AHT) technology has emerged as a promising solution to address crisis of the global energy consumption and environmental pollution of current heating and cooling processes. Hydrophilicity of water adsorbents plays a decisive role in these applications. This work reports an easy, green, and inexpensive approach to tuning the hydrophilicity of metal-organic frameworks (MOFs) by incorporating mixed linkers, isophthalic acid (IPA), and 3,5-pyridinedicarboxylic acid (PYDC), with various ratios in a series of Al−xIPA-(100−x)PYDC (x: feeding ratio of IPA) MOFs. The designed mixed-linkers MOFs show a variation of hydrophilicity along the fraction of the linkers. Representative compounds with a proportional mixed linker ratio denoted as KMF-2, exhibit an S-shaped isotherm, an excellent coefficient of performance of 0.75 (cooling) and 1.66 (heating) achieved with low driving temperature below 70 °C which offers capability to employ solar or industrial waste heat, remarkable volumetric specific energy capacity (235 kWh m −3 ) and heat-storage capacity (330 kWh m −3 ). The superiority of KMF-2 to IPA or PYDC-containing single-linker MOFs (CAU-10-H and CAU-10pydc, respectively) and most of benchmark adsorbents illustrate the effectiveness of the mixed-linker strategy to design AHT adsorbents with promising performance.

Shaping the Water-Harvesting Behavior of Metal–Organic Frameworks Aided by Fine-Tuned GPT Models

“…In previous work, originating from the linker structure of the state-of-the-art water-harvesting adsorbent MOF-303, a linker extension strategy can be employed to yield the new H2PZVDC linker through the introduction of a vinyl spacer to yield LAMOF-1 (Figure ). Further iterations on this structure, employing heteroatom replacement over several generations, yielded a suite of variants via multivariate tuning strategies. − This linker “evolution” introduced heterogeneity into the backbone, incorporating moieties such as pyrazole, thiophene, furan, thiazole, or an additional vinyl group. Cumulatively, this design paradigm represents a systematic expansion of linkers previously employed in the synthesis of certain aluminum rod MOFs. ,, Once a pool of linker candidates was proposed, they were selected based on commercial availability and evaluated by humans to propose routes for synthesis.…”

“…In this report, we present a multipronged approach to revolutionize the reticular design and synthesis of water-harvesting MOFs (Figure ). First, we report a family of 10 MOFs known as LAMOFs, synthesized through a synergistic integration of linker extension ,,− and multivariate (MTV) tuning strategies. − Second, we discuss how artificial intelligence (AI) can significantly accelerate the pace of research by efficiently proposing potential linker variants with minimum hallucinations, thereby reducing the number of labor-intensive tasks. In this work, we build a MOF linker mutation database, which consists of 3943 molecular editing examples, and use it to train large language models (LLMs) like GPT-3.5 to propose new MOF linker structures with high accuracy through a simple fine-tuning method.…”

Defect-containing metal–organic framework materials for sensor applications

“…The mixed linker approach, also a widely adopted strategy in the DNS methods, 55 involves directly combining two or more organic ligands as precursors during synthesis. 56 This concise and versatile method allows for the intentional introduction of defects, offering new possibilities for tailoring material properties.…”

Recent advances in metal–organic frameworks for water absorption and their applications

“…At 70 °C/30 °C in the adsorption chamber and 5 °C in the evaporation chamber, and KMF-2 performed a higher COP C of 0.75 exceeding CAU-10 (0.72). 125…”