Role Of Semiconductor Nanoparticles Functionalized With Silver Clusters As Photocatalysts Under UVA And White Light

BAVA YANINA BELÉN; M.A. LÓPEZ-QUINTELA; L. FERNÁNDEZ; C. VÁZQUEZVÁZQUEZ; M.T. MOREIRA; J. GONZÁLEZ-RODRÍGUEZ; D. BUCETA; G. FEIJOO

Naples

Congreso; NINE2019 - 3rd International Conference on NANOTECHNOLOGY BASED INNOVATIVE APPLICATIONS FOR THE ENVIRONMENT; 2019

AIDIC - Association of Chemical Engineering

Emerging contaminants (ECs) represent a wide and varied class of chemical compounds, whose complete elimination from wastewaters by conventional methods is not always guaranteed, representing risks associated with public health and ecosystem preservation. Advanced oxidation processes (AOPs) are based on the generation of highly oxidizing species, mainly hydroxyl radicals (OH●), which lead to the degradation of organic compounds. In the case of AOP technologies based on photochemical routes, the operating costs related to energy consumption (particularly in terms of the use of UV light) represent an important drawback that limits their implementation in full-scale systems. In this context, TiO2 and ZnO are the most widely used inorganic photocatalysts, mainly due to their low cost and wide availability; however, their use requires ultraviolet (UV)light. Aiming to overcome this impediment, the addition of small amounts of noble metals in the form of metal clusters may lead to greater absorption in the visible range of the spectrum and an attenuation effect on the recombination rate of the electron/hole pairs generated by light absorption, resulting in improved photocatalytic activity.In this work, we propose the use of heterogeneous photocatalysts, made up of silver clusters deposited on ZnO nanoparticles (ZnO-Ag), with the aim of evaluating their catalytic activity both under ultraviolet A (UVA) and in the optical window of visible light, in order to reduce energetic requirements in prospective applications on a larger scale. The catalysts were produced and characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and inductively coupled plasma ? optical emission spectrometry (ICP-OES). To investigate their potential in water treatment, experiments were carried out towards the photodegradation of the azo dye Orange II (OII). The results obtained showed a drastic reduction in the concentration of OII.