New materials to improve water quality
The PHOTOMAT (Tunable materials: Preparation, characterization and investigation of photocatalytic activity of new hybrid materials) project developed new materials with tunable properties, combining good mechanical properties and photocatalytic activity. Advanced materials were synthesised, characterised and evaluated for their photocatalytic efficiency in abating pollutants such as emerging pollutants. Scientists developed high-quality carbon nanoparticles (CNPs) for producing polymer nanocomposites. CNPs include carbon nanotubes (CNTs) and functionalised graphene sheets. CNTs were grown using chemical vapour deposition, whereas functionalised graphene sheets were synthesised by the rapid thermal expansion of graphite oxide. The materials were then surface modified using controlled oxidation and diazonium chemistry. Surface modification of CNTs allowed in situ control of the synthesis of titanium dioxide (TiO2) nanoparticles on graphene sheets. By changing surface functional groups, researchers synthesised nanoparticles with different morphology, exposing different facets. The ability to control TiO2 morphology and its coupling to graphene was found to have a deep impact on the photocatalytic activity of the hybrid material. Graphene functionalised with carboxylic groups proved to be a suitable candidate in binding the amino groups in proteins. A first successful example was reported in using this hybrid material as a substrate for a multi-analyte homogeneous immunoassay. Another task was to prepare semiconductor oxides and dope them with non-metal elements. Different techniques were used to obtain materials with different morphology and high surface area, with hydrothermal and precipitation being amongst the most promising methods. Cerium-doped zinc oxide demonstrated exceptional ability as a photocatalyst and in abating pollutants. Scientists combined CNTs, functionalised graphene and the semiconductor nanoparticles in ultraviolet-cured polymeric films. Cured films with dispersed carbon fillers proved to be good photocatalysts, and cross-linked films containing gold-functionalised graphene demonstrated improved electrical conductivity. Scientists explored different routes to obtaining self-supporting composites in which materials can be dispersed. In particular, they used electrospinning, graphene scaffolds, thermal conductive composites and polydopamine-functionalised membranes. Made up from nanoscopic fibres, electrospun materials can lead to obtaining films with very high surface areas and therefore excellent photocatalytic efficiency. Membranes functionalised with polydopamine demonstrated exceptional ability in removing dyes from wastewater. PHOTOMAT's novel nanomaterials have a significant impact on the photocatalytic breakdown of water pollutants, thereby protecting public health in Europe.
Keywords
Hybrid materials, water pollutants, PHOTOMAT, photocatalytic activity, carbon nanotubes, graphene, doped zinc oxide
