Biomass-derived carbon quantum dot: "On-off-on" fluorescent sensor for rapid detection of multi-metal ions and green photocatalytic CO2 reduction in water

Autor(es)

Raja, Sebastian ; da Silva, Gelson T. S. T. ; Anbu, Sellamuthu ; Ribeiro, Caue ; Mattoso, Luiz H. C.

• Tipo de documento: Artigo Científico
• Fonte: BIOMASS CONVERSION AND BIOREFINERY; v. N/A, p. 13-pg., 2023-05-02.

Resumo

We have developed carbon quantum dots (CQDs) with excellent photoluminescence (PL) properties from macauba (Acrocomia aculeate) fibers; a widely available cellulosic biomass species of palm trees in South America. As-prepared CQDs showed quasi-spherical morphology with high aqueous solubility and strong excitation-dependent fluorescence behaviour. Interestingly, the CQDs display fluorescence 'turn-off' response with excellent sensitivity toward multi-metal ions including Fe3+, Cu2+ and Hg2+ with very low detection limits of 0.69 mu M, 0.99 mu M, 0.25 mu M, respectively. Notably, ascorbic acid (AA) induced a change in the (turn-off) fluorescence of Fe3+-CQDs, which caused an almost 70% revival of fluorescence (turn-on) by displacing Fe3+ ions. We have also harnessed CQDs as the visible-light-induced photocatalyst to reduce CO2 in water. Especially, the CQDs efficiently promote the photocatalytic reduction of CO2 into methane (CH4) with an evolution rate of 99.8 nmol/g at 436 nm in aqueous conditions. This indicates that the CQDs provide abundant active sites for CO2 adsorption and thus enhance the separation and migration of photo-induced charge carriers that efficiently reduce CO2 into CH4 without any co-catalyst in 100% water. (AU)

• Processo FAPESP: 18/01258-5 - Novos processos catalíticos e fotocatalíticos para a conversão direta de metano e CO2 em produtos
• Beneficiário: José Maria Correa Bueno
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 17/22017-3 - Nanocristais de celulose (NIR - CNC) de infravermelho próximo (NIR) para bioimagem celular
• Beneficiário: Raja Sebastian
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 15/00094-0 - Modificações químicas de nanowhiskers de celulose
• Beneficiário: Raja Sebastian
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado