Electrodeposited MOFs Membrane with In Situ Incorporation of Charged Molecules for Osmotic Energy Harvesting

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 18; pp. e2207559 - n/a
• Main Authors: Yao, Bing, Hussain, Shabab, Ye, Zhizhen, Peng, Xinsheng
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.05.2023
• Subjects: Aluminum oxide; cation selective transport; Cations; Electrodeposition; Energy conversion efficiency; Energy harvesting; HKUST‐1; Membranes; Metal-organic frameworks; Nanochannels; Nanotechnology; Polystyrene resins; polystyrene sulfonate; salinity gradient power generation; Sodium polystyrene sulfonate; Structural design; salinity gradient power generation; HKUST-1; cation selective transport; polystyrene sulfonate
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202207559

Ion‐selective membranes are considered as the promising candidates for osmotic energy harvesting. However, the fabrication of highly perm‐selective membrane is the major challenge. Metal‐organic frameworks (MOFs) with well‐defined nanochannels along functional charged groups show great importance to tackle this problem. Here, a series of dense sodium polystyrene sulfonate (PSS) incorporated MOFs composite membranes (PSS@MOFs) on a porous anodic aluminum oxide (AAO) membrane via in situ anodic electrodeposition process are developed. Benefiting to the novel structural design of the confined Ag layer, PSS@MOFs dense composite membrane with less defects formed. The sulfonated nanochannels of the PSS@MOFs composite membrane provided rapid and selective transport of cations due to the enhanced electrostatic interaction between the permeating ions and MOFs. While osmotic energy conversion, 860 nm thick negatively charged PSS@MOFs composite membrane achieves an ultrahigh cation transfer number of 0.993 and energy conversion efficiency of 48.8% at a 100‐fold salinity gradient. Moreover, a large output power of 2.90 µW has been achieved with an ultra‐low internal resistance of 999 Ω, employing an effective area of 12.56 mm2. This work presents a promising strategy to construct a high‐performance MOFs‐based osmotic energy harvesting system for practical applications. Polystyrene sulfonate (PSS)@metal‐organic framework composite membranes (PSS@MOFs) are prepared by electrodeposition. The resulted membranes show an energy conversion efficiency of 48.76% and low internal resistance of 999 Ω at a 100‐fold salinity gradient with an output power of 2.90 µW.