Nanohybrids based on F-doped titanium dioxides and carbon species with enhanced dual adsorption-photodegradation activity for water decontamination

Abstract

In recent years, titanium dioxide has shown high photocatalytic effectiveness when applied to different decontamination processes. However, the relatively low surface area of this material compared with those of other metal oxides limits its adsorption capacity. The modification of titanium dioxides with carbon species with high surface porosity is an excellent option in generating photocatalysts with high adsorption capacity and a promising activation potential. In addition, carbon materials may improve electron lifetime in TiO2 by decreasing charge recombination and reducing the band gap. In the present study, material synthesis has been carried out using different quantities of a variety of carbon species which were supported on mesoporous aggregates of photocatalytically active fluorine-doped anatase nanoparticles with ultra-reactive anatase facets {001}. These systems showed an initial adsorption capacity of 15–25% which favours an efficient photodegradation. High activity was observed in the adsorption/photodegradation of organic pollutants with elimination of up to 95% of concentrated solutions of methylene blue and common emerging pollutants such as ciprofloxacin (88%) and naproxen (75%) under UV light (300 W) in 10 min. Moreover, the systems were also doped with palladium nanoparticles thus becoming effective heterogeneous catalysts in Suzuki-Miyaura reactions with good to excellent halide conversions (between 80 and 99% for the formation of biphenyl derivatives) and high TON values (up to 110) at short reaction times and low Pd loading.

Keywords

• Titanium dioxide
• Fluorine doping
• Mesoporous carbon species
• Carbon nanotubes
• Graphene
• Photocatalysis