Sustainable synthesis of titanium based photocatalysts via surfactant templating: from kerosene to sunflower oil

Abstract

Recent research conducted by the United Nations indicates that 2 billion people worldwide lack access to safe, clean drinking water, while about half of the global population experiences acute water scarcity no less than once every year. Therefore, materials and technologies that sustainably address drinking water pollution and/or its treatment are urgently needed. This study aims to develop novel, sustainable titanosilicate photocatalysts by replacing expensive and harmful oils/surfactants, typically used as templating agents during their synthesis for pore structure generation, by cheap, innocuous and sustainable feedstocks such as sunflower oil. The results indicate that sunflower oil-based titanosilicates are more effective in degradation and removal of model pollutant Rhodamine B via combined photocatalysis-adsorption action, compared to their counterparts synthesized with a fossil-fuel derived kerosene oil mixture. Moreover, the catalysts are shown to be robust, recyclable, are ∼50% cheaper to produce on a laboratory scale and displayed up to three times the reaction rates of their conventional counterparts. Compared to commercial TiO₂ photocatalysts, these titanosilicates are shown to have superior overall stability in water. Additionally, they show bandgaps close to or lower than that of TiO₂ (3.2 eV), without the use of added dopants, providing more effective UV/visible light absorption. Thus, they have the potential to be used as sustainable yet effective alternatives in the treatment of drinking water.