Evaluation of structural and photocatalytic properties of g-C3N4/ZnO/carbon xerogel composites synthesized with different types of tannin

Author(s)

Juliana Giancoli Martins de Sousa ^[1] ; Nicolas Perciani de Moraes ^[2] ; Clarice Moreira Goes ^[3] ; Gustavo Viégas Jucá Dantas ^[4] ; Maria Lucia Caetano Pinto da Silva ^[5] ; Liana Alvares Rodrigues ^[6]

Affiliation

^[1] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

^[2] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

^[3] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

^[4] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

^[5] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

^[6] USP. Escola de Engenharia de Lorena. Departamento de Engenharia Química - Brasil

• Document type: Journal article
• Source: MATERIA-RIO DE JANEIRO; v. 27, n. 1 2022-05-06.

Abstract

ABSTRACT The influence of different carbonaceous precursors on the development of g-C3N4/carbon xerogel/ZnO photocatalysts was explored. The coupling between zinc oxide and graphitic carbon nitride is suitable for boosting the degradation of organic pollutants. The function of carbon xerogel is to improve charge transfer and increase catalyst activity under visible radiation. Different commercial tannins (PHENOTAN AP, AG and BS) were used to evaluate the precursor effect on the composite’s properties. X-ray diffractometry showed that the materials have the hexagonal crystal structure of zinc oxide. Diffuse reflectance spectra obtained exhibited the characteristic behavior of zinc oxide (λ<420nm). Furthermore, the material prepared with PHENOTAN AP had a superior visible light absorption capacity. The scanning electron microscopy analysis showed that the materials are composed of clusters of particles similar to spheres and the materials in particle size. The dispersive energy spectroscopy analysis was performed only for the material prepared with PHENOTAN AP and evidenced that all elements are well distributed in g-C3N4/carbon xerogel/ZnO matrix. The nitrogen adsorption isotherms of the materials showed that the isotherms characteristics (type IV-H3), whereas the material synthesized with PHENOTAN AP has the largest specific surface area. The pore distribution of the materials showed that the materials had most developed porous structure, with pores ranging from 20 nm to 40 nm. Through thermogravimetry analysis it is possible to observe that the PHENOTAN AP has superior thermal stability. It was observed that the precursor used in the synthesis of composites significantly influences the photocatalytic activity of the materials. The composite with the highest photodegradation efficiency of 4-Chlorophenol under solar radiation was prepared with PHENOTAN AP, since it has a superior visible radiation absorption, greater amount of carbon, greater surface area and greater volume of pores. It is also worth noting that there was no significant adsorption of 4-chlorophenol in the materials synthesized, as well as no leaching of the photocatalysts during the process. (AU)

• FAPESP's process: 19/03641-3 - Photodegradation of 4-chlorophenol using ZnO/SnO2/carbon xerogel composite as catalyst
• Grantee: Clarice Moreira Goes
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 18/10492-1 - Photocatalytic evaluation of heterojunctions semiconductor/ZnO/carbon xerogel in the photodegradation of 4-chlorophenol in both fluidized bed and batch reactors
• Grantee: Liana Alvares Rodrigues
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/16360-0 - Development of ZnO/Bi2O3/Carbon xerogel ternary composites as photocatalysts for the degradation of persistent organic pollutants
• Grantee: Nicolas Perciani de Moraes
• Support Opportunities: Scholarships in Brazil - Doctorate