2026-04-29T17:06:12Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/110642025-11-15T01:05:32Zcom_10259_5822com_10259_5086com_10259_2604col_10259_5823

Graphene quantum dot-based hydrogels for photocatalytic degradation of organic dyes Ibarbia, Antton Sánchez-Abella, Laura Lezama, Luis Grande, Hans J. Ruiz Fernández, Virginia Graphene quantum dot Hydrogel Photocatalysis Dye photodegradation Peroxidase activity Nanozyme Química analítica Ciencia de materiales Chemistry, Analytic Materials science Graphene oxide quantum dots (GOQD) covalently immobilized in hydrogels have shown great promise as artificial enzymes for the photodegradation of the organic dye rhodamine B (RhB). Suitably functionalized with cross-linkable 3-(triethoxysilyl)propyl methacrylate (MPS) units, GOQD-MPS were incorporated by free radical copolymerization into poly[2-(Methacryloyloxy)ethyl]trimethylammonium]-co-(3-Sulfopropylmethacrylate) 50:50 (A50coS50) hydrogels with known antiadhesive properties. The peroxidase mimetic activity of GOQD solutions for the oxidation of chromogenic peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in presence of hydrogen peroxide increased significantly upon functionalization with MPS. Consequently, composite GOQD-A50coS50 hydrogels also exhibited high peroxidase activity for TMB oxidation. Moreover, GOQD-MPS solutions and GOQD-A50coS50 hydrogels showed remarkable catalytic activity for degradation of model RhB dye in darkness, an activity that was notably enhanced by visible light irradiation. The photoactivity depended on GOQD-MPS loading and hydrogel volume. Interestingly, GOQD-A50coS50 hydrogels retained the high photocatalytic activity after several months stored wet as well as after undergoing drying-rehydration processes, key from a practical point of view for applications in water treatment. The activity of rehydrated hydrogels for RhB photodegradation was only reduced by 15% compared to the activity of a non-dried hydrogel under the same test conditions. Financial support from the Basque Government under the ELKARTEK program (ACTIMAT project, grant KK-2018/00099) is gratefully acknowledged. The authors wish to thank Prof. Andrey Chuvilin from CIC nanoGUNE (Donostia-San Sebastián, Spain) for TEM characterization of hydrogels and Eider Beguiristain (CIDETEC) for help with hydrogel characterization. 2025-11-14T13:23:00Z 2025-11-14T13:23:00Z 2020-10 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion 0169-4332 https://hdl.handle.net/10259/11064 10.1016/j.apsusc.2020.146937 eng Applied Surface Science. 2020, V. 527, 146937 https://doi.org/10.1016/j.apsusc.2020.146937 Attribution-NonCommercial-NoDerivatives 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess application/pdf Elsevier