Graphene quantum dot-based hydrogels for photocatalytic degradation of organic dyes

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 incorporat...

ver descrição completa

Detalhes bibliográficos
Autores: Ibarbia, Antton, Sánchez-Abella, Laura, Lezama, Luis, Grande, Hans J., Ruiz Fernández, Virginia
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2020
País:España
Recursos:Universidad de Burgos (UBU)
Repositório:Repositorio Institucional de la Universidad de Burgos (RIUBU)
OAI Identifier:oai:riubu.ubu.es:10259/11064
Acesso em linha:https://hdl.handle.net/10259/11064
Access Level:Acceso aberto
Palavra-chave:Graphene quantum dot
Hydrogel
Photocatalysis
Dye photodegradation
Peroxidase activity
Nanozyme
Química analítica
Ciencia de materiales
Chemistry, Analytic
Materials science
Descrição
Resumo: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.