Influência do tratamento térmico assistido por pressão na energia de gap de materiais modificados Ti:Nb:Ru

Abstract

This study aims to analyze the impact of pressure-assisted thermal treatment (PAHT) on the properties of modified semiconductor oxides, focusing on Ti:Nb:Ru oxides synthesized via sol-gel, varying compositions (100Ti, 100Nb, 50Ti:50Nb) and including doping with ruthenium. The sol-gel methodology is presented as a versatile approach for controlled synthesis and the application of PAHT is explored to improve the synthesis of semiconductor oxides. Semiconductors are essential in catalysts, solar cells, and photocatalysts, especially when doped to improve the efficiency of hydroxyl radical formation. The experimental procedures involved submitting the developed oxides to PAHT, varying pressure and temperature, followed by morphological, optical, and structural analysis using scanning electron microscopy, Raman spectroscopy, UV-Vis spectroscopy, photoacoustic spectroscopy, and X-ray diffraction. The conclusions highlight significant changes in morphological and optical properties, especially in the band gap and visible light absorption, after PAHT. The results indicate that the 100Ti:1Ru oxide, obtained by the sol-gel method, calcined at 800 °C, and subjected to PAHT, presents promising characteristics for chemical reactions activated by solar radiation, with a notable reduction in band gap and visible absorption. Furthermore, PAHT promoted more stable crystalline phases at temperatures much lower than those indicated in the literature related to synthesizing titanium dioxide and niobium pentoxide. These discoveries contribute significantly to the advancement of knowledge, providing valuable guidance for developing and optimizing materials with specific properties in technological applications.