TiO2 Surface Hybridisation with Noble Metals (Ag and CuxO) for Solar De-NOx and VOC Removal

Abstract

<p>Indoor and outdoor air pollution remains a major health risk for human beings. Nitrogen oxides and volatile organic compounds are amongst the major pollutant found outdoor. Thus, actions to diminish such risks and to provide safer outdoor / indoor environment are required. In this research work, we have decorated the surface of TiO<sub>2</sub> with noble-metal oxides (Ag and/or Cu<i><sub>x</sub></i>O) to improve the photocatalytic performances (removal of nitrogen oxides and benzene) under simulated solar-light irradiation. By means of advanced X-ray methods it has been shown that noble metals did not enter the TiO<sub>2</sub> crystal structure, although they retarded the anatase-to-rutile phase transition and crystal growth. </p> <p>Photocatalytic activity was assessed in the gas-solid phase, monitoring the degradation of NO<i><sub>x</sub></i> and benzene, using a lamp simulating the solar radiation. Results showed that TiO<sub>2</sub> modified with an Ag:Cu molar ratio equal to 1:1 (with Ag+Cu = 0.5+0.5 mol% = 1 mol%), was that exhibiting best de-NO<i><sub>x</sub></i> and benzene removal performances.</p>