Successful CO2 reduction under visible light photocatalysis using porous NiO nanoparticles, an atypical metal oxide

An efficient, one-pot wet chemical synthesis strategy for the preparation of NiO nanoparticles has been reported. The nanostructured NiO has surface bound hexamine and it has emerged as a proficient catalyst for the conversion of carbon dioxide (CO2) into formaldehyde with a maximum turnover number of 369 in the presence of blue LED light. The nano-photocatalyst has shown great catalytic efficiency (in terms of the turnover number) and excellent reusability for the photoreduction of CO2. To the best of our knowledge this will be the first report on photoreduction of CO2 to formaldehyde in water under visible light irradiation using NiO nanoparticles as the photocatalyst. The as-prepared NiO nanomaterial has been thoroughly characterized using several spectroscopic and microscopic techniques, e.g. UV-vis spectroscopy, PXRD, XPS, SEM, FESEM and TEM. The mechanism of formation has been predicted from a detailed FTIR analysis.