Schottky-like photo/electro-catalytic carbon nanotube composite ultrafiltration membrane reactors. (February 2023)

• Record Type: Journal Article
• Authors: Rashed, Ahmed O.; Huynh, Chi; Merenda, Andrea; Qin, Si; Usman, Ken Aldren S.; Sadek, Abu; Kong, Lingxue; Kondo, Takeshi; Dumée, Ludovic F.; Razal, Joselito M.
• Is Part Of: Carbon. Volume 204(2023)
• Page Start: 238
• Page End: 253
• Publication Date: 2023-02
• Subjects: Carbon nanotube spinning -- Carbon nanotube membranes -- Catalytic membrane reactor -- Schottky-like nanocomposites -- Photo/electro-catalytic membrane; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.12.073
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Stimuli-responsive membrane reactors offer advanced strategies towards simultaneous separation and degradation of persistent organic contaminants, allowing for triggered response through photo or electro stimuli. However, the scalable fabrication of stimuli-responsive nanoporous membranes with high selectivity and catalytic reactivity is still challenging in practical application. Here, photo-electro responsive membranes were designed by assembling carbon nanotubes (CNT) scaffolds decorated with conformal nanoscale SnO2 coatings. The membranes, built from spinnable CNT materials supported the generation of a unique class of ultrathin and flexible ultrafiltration membranes with thicknesses down to 25 nm and pore size as narrow as ∼20 nm. The CNTs were used as effective conductive photosensitizers to promote charge transfer from the graphitic to the SnO2 layer, supporting synergistic effects arising from generated Schottky-like diodes to improve the photo/electro-catalytic activity of nanocomposite membranes. The SnO2 -CNT membranes exhibited high water permeance of 2.24 × 10 3 L m −2 h −1 .bar −1, and faster reaction kinetics of 77.6 × 10 −3 for acetaminophen degradation, which was 2–10 times higher than the kinetics achieved by currently available catalytic membrane reactors. The structural stability and outstanding performance of SnO2 -CNT membranes were maintained over 8 reuse cycles with ∼99% degradation efficiency against acetaminophen in 60 min. The unique solid-state fabrication method of uniformly coated catalytic metal oxide on well aligned CNTs provides a scalable feasible approach to produce high-performance ultrafiltration photo/electro-catalytic membrane reactors towards cost-effective water purification at a competent reaction rate. Graphical abstract: Image 1 Highlights: Schottky-like SnO2 -CNT membranes are developed via solid-state CNT spinning and SnO2 atomic layer deposition. Stimuli-responsive SnO2 -CNT ultrafiltration membranes exhibit fine-tuned pore size down to 20 nm. Synergistic photo/electro-catalytic performance is boosted via generated SnO2 -CNT Schottky barriers. A feasible approach to engineer high performance CNT-based catalytic membrane reactors. High water permeance and fast reaction kinetics are achieved during photo/electro-catalytic ultrafiltration of acetaminophen.