ABSTRACT
This study presents a green method of producing copper nanoparticles (CuNPs) using aqueous extracts from Sargassum spp. as reducing, stabilizing, and capping agents. The CuNPs created using this algae-based method are not hazardous, they are eco-friendly, and less toxic than their chemically synthesized counterparts. The XRD characterization of the CuNPs revealed the presence of Cu and CuO, with a crystallite size ranging from 13 to 17â nm. Following this, the CuNPs were supported onto a carbon substrate, also derived from Sargassum spp. (biochar CSKPH). The CuNPs in biochar (CuNPs-CSKPH) did not appear in the XRD diffractograms, but the SEM-EDS results showed that they accounted for 36 % of the copper weight. The voltamperometric study of CuNps-CSKPH in acid media validated the presence of Cu and the amount was determined to be 2.58â µg. The catalytic activity of CuNPs-CSKPH was analyzed for the electrochemical reduction of CO2. The use of Sargassum spp. has great potential to tackle two environmental problems simultaneously, by using it as raw material for the synthesis of activated biochar as support, as well as the synthesis of CuNPs, and secondly, by using it as a sustainable material for the electrochemical conversion of CO2.
Subject(s)
Carbon Dioxide , Copper , Electrochemical Techniques , Green Chemistry Technology , Metal Nanoparticles , Oxidation-Reduction , Sargassum , Copper/chemistry , Sargassum/chemistry , Carbon Dioxide/chemistry , Metal Nanoparticles/chemistry , Charcoal/chemistry , Catalysis , Particle SizeABSTRACT
A four stage semi-pilot scale RFR reactor with ceramic disks as support for TiO2 modified with silver particles was developed for the removal of organic pollutants. The design presented in this article is an adaptation of the rotating biological reactors (RBR) and its coupling with the modified catalyst provides additional advantages to designs where a catalyst in suspension is used. The optimal parameter of rotation was 54 rpm and the submerged surface of the disks offer a total contact area of 387 M². The modified solid showed a decrease in the value of its bandgap compared to commercial titanium. The system has a semi-automatic operation with a maximum reaction time of 50 h. Photo-activity tests show high conversion rates at low concentrations. The results conform to the Langmuir heterogeneous catalysis model.
