Agradecimentos: The authors acknowledge the financial support provided by the Sao Paulo Research Foundation (Grants No 2018/10492-1, No 2018/12035-7, No 2017/10118-0, No 2013/02762-5 and No 2018/16360-0) and by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (Grants No 155550/2018-7 and No 405543/2016-6). The authors are also grateful to TANAC S.A., which supplied the black wattle tannin Ver menos

Abstract: This work aimed to study the development and properties of Bi-doped ZnO/beta-Bi2O3/Carbon xerogel composites towards visible light photocatalysis applications. The materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, dispersive energy spectroscopy, infrared spectroscopy, nitrogen adsorption isotherms, Raman spectroscopy, diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. The photocatalytic activity of the developed composites was evaluated through the photo degradation of the 4-chlorophenol molecule and by chronoamperometry tests. The results obtained show that the calcination temperature poses a major influence in the final structure of the materials developed. The calcination temperature of 600 degrees C resulted in the formation of the beta-Bi2O3 and Bi-0 phases, consequently enhancing the photocatalytic activity of the composites due to the increased charge mobility provided by the heterojunctions between zinc oxide, carbon xerogel, bismuth oxide and metallic bismuth. The composite with intermediate bismuth composition (XC/ZnO-Bi2O3 5%) displayed the best photocatalytic response among the materials tested, which was confirmed by its increased photocurrent generation capability. The photocatalytic mechanism is highly dependent in the generation of hydroxyl radicals and the composite presents good reusability properties Ver menos