Evaluation of ZnO/Carbon Xerogel Composite as a Photocatalyst for Solar and Visible Light Degradation of the Rhodamine B Dye

Abstract

This study is focused on the evaluation of the Rhodamine B photodegradation using ZnO/carbon xerogel composite as a photocatalyst, in order to enhance the photocatalytic process efficiency under visible light. The proposed synthesis employs tannin as a precursor for the carbon xerogel, which enhances the economic and environmental aspect of the composite. The synthesized materials have the hexagonal structure of the zinc oxide (wurtzite), which is homogeneously distributed on the carbonaceous matrix. The diffuse reflectance test shows that light absorption was significantly enhanced for the composite. The solar light-driven photodegradation results revealed that the synthesized composite achieved virtually complete degradation of the dye present in the solution in less than 3 h, in all concentrations tested. The results of visible light driven photocatalysis showed that the carbonaceous material presents better photoactivity than the pure oxide (70% and 40% degradation of Rhodamine B, respectively), due to the synergistic effect between the carbon xerogel and zinc oxide on the properties of the composite. The photocatalytic mechanism main active species are the photogenerated vacancies and superoxide radicals.

Visible Light Active Photocatalysts for Environmental Remediation and Organic Synthesis

“…ZnO/carbon xerogel composite were prepared using tannin as carbon source [93]. The diffuse reflectance test demonstrated that light absorption was significantly enhanced for the composite, while the solar light-driven photodegradation tests revealed that the synthesized composite achieved almost complete degradation of Rhodamine B.…”

Enhanced Effluent Degradation with Zinc Oxide, Carbon Nitride, and Carbon Xerogel Trifecta on brass monoliths

“…On the other hand, the incorporation of carbonaceous materials into the system, such as carbon xerogels (CX), can help reduce this drawback. These materials exhibit desirable intrinsic properties for photocatalytic reactions, such as high surface area, high absorption of visible radiation, and high conductivity, which can act as electron reservoirs (Moraes et al 2022;Cunha et al 2021;Santos et al 2021).…”

Desenvolvimento de compósitos ternários ZnO/Bi>sub<2>/sub<O>sub<3>/sub</Xerogel de carbono como fotocatalisadores para a degradação de poluentes orgânicos persistentes

“…Como esperado, a Figura 85 mostra que os materiais XCL/ZnO 1.0 e XCL/ZnO-Bi2O3 5% apresentam uma maior capacidade de absorver radiações de menor energia, quando comparados ao óxido de zinco puro. Como discutido anteriormente, esse comportamento é derivado da presença da fase carbonosa no material e pode levar à uma maior atividade dos compósitos quando submetidos à processos baseados em radiação natural (Santos et al, 2021).…”