beta-Cyclodextrin as a Precursor to Holey C-Doped g-C3N4 Nanosheets for Photocatalytic Hydrogen Generation

• Tipo: Artigo em Revista Científica Internacional
• Data: 2018

Autores

Eliana S. da Silva (Autor) FEUP; Nuno M. M. Moura (Autor) Outra; Ana Coutinho (Autor) Outra; Goran Drazic (Autor) Outra; Bruno M. S. Teixeira (Autor) Outra; Nikolai A. Sobolev (Autor) Outra; Cláudia G. Silva (Autor) FEUP; M. Graça P. M. S. Neves (Autor) Outra; Manuel Prieto (Autor) Outra; Joaquim L. Faria (Autor) FEUP

Revista

Título: ChemSusChem

Vol. 11 Nº 16

Páginas: 2681-2694

ISSN: 1864-5631

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 10 Citações

ISI Web of Science

Scopus - 43 Citações

Classificação Científica

CORDIS: Ciências Tecnológicas > Engenharia > Engenharia química

FOS: Ciências da engenharia e tecnologias > Engenharia química

Projetos Associados

IF/00514/2014/CP1249/CT0004 - Desafiando a síntese em química fina: uma nova abordagem utilizando fotocatalisadores isentos de metais

Outras Informações

ID Authenticus: P-00P-HEQ

DOI: 10.1002/cssc.201801003

Abstract (EN): A green, template-free and easy-to-implement strategy was developed to access holey g-C3N4 (GCN) nanosheets doped with carbon. The protocol involves heating dicyandiamide with beta-cyclodextrin (beta CD) prior to polymerization. The local symmetry of the GCN skeleton is broken, yielding CxGCN (x corresponds to the initial amount of beta CD used) with pores and a distorted structure. The electronic, emission, optical and textural properties of the best-performing material, C2GCN, were significantly modified as compared to bulk GCN. The spectroscopic and luminescent features of C2GCN show the characteristic pi-pi* electronic transition of GCN, accompanied by much stronger n-pi* electronic transitions owing to the porous and distorted network. These new electronic transitions, along with the presence of additional carbon synergistically contributed to enhanced visible light absorption and restrained recombination of electron-hole pairs. Steady-state and time-resolved photoluminescence showed an effective quench of the fluorescence emission, accompanied by a decrease of fluorescence lifetime of C2GCN (2.20 ns) in comparison with GCN (5.85 ns), owing to the delocalization of electron and holes to new recombination centers. The photocatalytic activity of C2GCN was attributed to efficient charge carrier separation and improved visible-light absorbing ability. As result, C2GCN exhibited similar to 5 times higher photocatalytic H-2 generation under visible light than bulk GCN.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14