Synthesis, structure analysis and Fenton-like catalytic properties of copper-modified graphitic carbon nitride

Author(s)

Almeida, Janio S. ; Batista, Walker F. C. ; Barbosa, Luele R. S. ; Damaceno, Fernanda B. ; Pires, Manoel Jose Mendes ; Mesquita, Joao Paulo ; Mastelaro, Valmor R. ; dos Santos, Wayler Silva ; Pereira, Marcio Cesar ; Mourao, Henrique A. J. L.

• Document type: Journal article
• Source: MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING; v. 181, p. 11-pg., 2024-06-26.

Abstract

Heterogeneous catalysts based on graphitic carbon nitride (g-C 3 N 4 ) modified by metals have received increasing attention due to the possibility of obtaining materials with better structural properties and catalytic performance. However, achieving a high content of metal-Nx species from the pyrolysis of the precursor mixture and a clear understanding of the structure of these materials are still challenges to be overcome. Herein, copper -modified graphitic carbon nitride materials were synthesized using different proportions in mass of the cooper/melamine precursors. The synthesized catalysts were characterized by a variety of techniques, which include X-ray diffractometry (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), electrochemical impedance (Mott -Schottky plots), among others. The results reveal structural and surface changes in the g-C 3 N 4 matrix after incorporating copper ions. The prepared materials were used as catalyst in Fenton and the pseudo -first -order kinetic model was used to describe the catalytic process of degradation of methylene blue (MB) and indigo carmine (IC) dyes. The MB degradation was 100 % in the CuCN-30/H 2 O 2 system after 20 min of reaction at a removal rate of 0.2 min -1 , while for IC, the CuCN-15/ H 2 O 2 system obtained 87 % removal after 40 min at 0.04 min -1 . The copper ions were directly responsible for generating highly reactive radicals (mainly center dot O 2 - ) from H 2 O 2 . In this way, the Cu -modified samples presented unique properties of bulk and surface, good stability, excellent activity (especially under neutral and alkaline conditions) and, therefore, are promising for applications in environmental remediation processes. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC