Work

A tin disulfide/vanadium carbide MXene@cellulose acetate-nanofiltration (SnS2/V2CTx@CA-NF) membrane for photocatalytic degradation of perfluorononanoic acid (PFNA)

Year: 2026

Type: article

Abstract: Perfluorononanoic acid (PFNA) is a persistent pollutant that poses significant environmental and health risks, demanding advanced photodegradation methods. This study introduces a tin disulfide/vanadium carbide MXene (SnS 2 /V 2 CT x ) Schottky junction incorporated into a polyamide layer for efficient photocatalytic degradation of PFNA. The support membrane employed in this study was cellulose acetate, fabricated using a phase inversion method. This resulted in a photocatalytic thin-film composite membrane denoted as (SnS 2 /V 2 CT x )@CA-NF. The membrane pore size was assessed using the convection-diffusion model, which indicated a decrease of 0.88 nm for the pristine membrane to 0.77 nm for the modified membrane. The thin-film composite membrane also exhibited an enhanced pure water flux, increasing from 70.97 L/m −2 ·h for CA-NF to 150.11 L/m −2 ·h for the (SnS 2 /V 2 CT x )@CA-NF modified membrane. Moreover, the (SnS 2 /V 2 CT x ) 1.0% @CA-NF membrane showed enhanced salt rejection of both NaCl (90.20% and 89.37%) and Na 2 SO 4 (94.65% and 94.50%) at low and high concentrations (1000 and 5844 mg/L), respectively. Liquid chromatography mass spectrometry (LC-MS/MS) was employed to monitor the degradation efficiency and to study the by-products formed as a result of PFNA photodegradation. An enhanced photodegradation efficiency of 88% was obtained for the (SnS 2 /V 2 CT x ) 1.0% @CA-NF membrane opposed to the pristine CA-NF membrane. The PFNA pollutants fragmented into smaller organic molecules, including perfluoropentanol (C 5 HF 11 O) and Trifluoroacetaldehyde (C 2 HF 3 ). The detected final fragments presented relatively smaller mass-to-charge ratio ( m/z ) values of 97.9979 m/z compared to the parent counterpart, which was 463.9665 m/z , suggesting efficient photocatalytic decompositions. This work demonstrates the promising potential of integrating photocatalysis with membrane separation to efficiently remove and degrade persistent organic pollutants in water systems.

Source: Separation and Purification Technology

DOI: 10.1016/j.seppur.2026.140109

Authors: Valentia Pheladi Letswalo, Thollwana Andretta Makhetha, Mathapelo Pearl Seopela, Anthony Szymczyk, Soraya Phumzile Malinga

Institutions: University of Johannesburg, Institut des Sciences Chimiques de Rennes, Université de Rennes

Language: English

Topic: Membrane Separation Technologies

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $4,060