UK Catalysis Hub

Professor Graham Hutchings and Dr Josie Goodall explain the function of the UK Catalysis Hub and how it is working to maintain the UK’s position as a global scientific and industrial leade

In situ spectroscopic monitoring of CO2 reduction at copper oxide electrode

Copper oxide modified electrodes were investigated as a function of applied electrode potential using in situ infrared spectroscopy and ex situ Raman and X-ray photoelectron spectroscopy. In deoxygenated KHCO3 electrolyte bicarbonate and carbonate species were found to adsorb to the electrode during reduction and the CuO was reduced to Cu(I) or Cu(0) species. Carbonate was incorporated into the structure and the CuO starting material was not regenerated on cycling to positive potentials. In contrast, in CO2 saturated KHCO3 solution, surface adsorption of bicarbonate and carbonate was not observed and adsorption of a carbonato-species was observed with in situ infrared spectroscopy. This species is believed to be activated, bent CO2. On cycling to negative potentials, larger reduction currents were observed in the presence of CO2; however, less of the charge could be attributed to the reduction of CuO. In the presence of CO2 CuO underwent reduction to Cu2O and potentially Cu, with no incorporation of carbonate. Under these conditions the CuO starting material could be regenerated by cycling to positive potentials

Optical and photocatalytic behaviours of nanoparticles in the Ti-Zn-O binary system

Continuous hydrothermal flow synthesis (CHFS) has been used as a rapid and clean, synthetic method to produce a range of crystalline nanoparticles in the Ti-Zn-O binary system. The nanopowders were prepared from aqueous solutions of titanium(iv) bis(ammonium lactato)dihydroxide (TIBALD) and hydrated zinc nitrate, respectively, using a CHFS reactor which uses superheated water (at 400°C and 24.1 MPa) as a reagent and crystallizing medium. The resulting nanopowders were heat-treated at 850°C for five hours in air to give photoactive semiconductor mixtures of rutile and zinc oxide and/or zinc titanates. The as-prepared powders and their corresponding heat-treated mixed phase photocatalysts were characterized using powder X-ray synchrotron diffraction, transmission electron microscopy, BET surface area measurement, X-ray photoelectron spectroscopy and UV-Vis spectrophotometry. Because of the interest for these materials in UVA and UVB attenuating materials, the UV-Vis profiles of the nanocomposites and solid solutions were studied. Photocatalytic activity of the samples towards the decolourisation of methylene blue dye was also assessed. © 2014 the Partner Organisations