**TiO2-SiO2-PMMA Terpolymer Floating Device for the Photocatalytic Remediation of Water and Gas Phase Pollutants**

**Valentina Sabatini 1,2,3,\*, Luca Rimoldi 1,2,\*, Laura Tripaldi 1,2, Daniela Meroni 1,2,\*, Hermes Farina 1,2,3, Marco Aldo Ortenzi 1,2,3 and Silvia Ardizzone 1,2,3**


Received: 23 October 2018; Accepted: 16 November 2018; Published: 21 November 2018

**Abstract:** Floating photocatalytic devices are highly sought-after as they represent good candidates for practical application in pollutant remediation of large water basins. Here, we present a multilayer floating device for the photocatalytic remediation of contaminants present in water as well as of volatile species close to the water surface. The device was prepared on a novel tailored ter-polymer substrate based on methylmethacrylate, α-methylstyrene and perfluoroctyl methacrylate. The ad hoc synthesized support presents optimal characteristics in terms of buoyancy, transparency, gas permeability, mechanical, UV and thermal stability. The adhesion of the TiO2 top layer was favoured by the adopted casting procedure, followed by a corona pre-treatment and by the deposition of an intermediate SiO2 layer, the latter aimed also at protecting the polymer support from photocatalytic oxidation. The device was characterized by contact angle measurement, UV-vis transmittance and scanning electron microscopy. The final device was tested for the photocatalytic degradation of an emerging water pollutant as well as of vapors of a model volatile organic compound. Relevant activity was observed also under simulated solar irradiation and the device showed good stability and recyclability, prospecting its use for the photocatalytic degradation of pollutants in large water basins.

**Keywords:** composite; polymethylmethacrylate; photocatalytic oxidation; titanium dioxide; tetracycline; ethanol
