The reformation of CO 2 through photocatalytic processes to obtain products with high energy value and compatibility with the current energy infrastructure is a compelling strategy to minimize the emission of CO 2 into the atmosphere, one of the main greenhouse gases. However, practical application of such a photocatalytic system requires significant efforts for improved CO 2 photoreduction performance and product selectivity. Thus, in the present work, CuO nanoparticles were combined with Nb 2 O 5 in order to improve the photocatalytic properties of these semiconductors in the CO 2 photoreduction process. Nb 2 O 5 / CuO heterojunctions were prepared via a solvothermal treatment method, while the experimental tools, such as FESEM, HRTEM, and DRS, were employed to evaluate the microstructural and electronic properties. We describe how CuO decoration over Nb 2 O 5 adjusts its selectivity for CO 2 reduction to CH 4 , HCOOH, or H 3 CCOOH in different contents. An investigation of CO 2 photoreduction using different electron donors/scavengers (water, sodium oxalate, and potassium bromate) under ultraviolet radiation revealed that its decoration influences local CO production by modifying the selectivity. CO has been confirmed as the main intermediate for HCOOH and CH 3 COOH production, and CO 2 reduction efficiency increases at low CuO content (2.5% wt), leading to the formation of soluble hydrocarbons, and increases for CH 4 in higher amounts (10% wt).
Environmental problems related to the generation of wastewater contaminated with organic compounds and the emissions of pollutants from fuel burning have become major global problems. Thus, there is a need for the development of alternative and economically viable technologies for the remediation of the affected ecosystems. Therefore, this work describes the preparation and characterization of a Ti(OH)4 catalyst with the modified surface for application in the photodegradation of organic compounds (methylene blue (MB) dye and the drug amiloride (AML)) and in the artificial photosynthesis process. Characterization results reveal that peroxo groups on the surface of the catalyst had a great influence on the optical properties of the Ti(OH)4 and consequently in its photocatalytic property. This catalyst showed a high photocatalytic activity for the degradation of organic pollutants under visible radiation, reaching approximately 98% removal of both the dye and the drug in 150 min of reaction. In addition, the catalyst presented a great potential for the reduction of CO2 under ultraviolet (UV) radiation when compared to P25, which is a classic catalyst used in photocatalytic processes. The highest photocatalytic activity can be attributed to the strong visible light absorption, due to the narrow band gap, and the effective separation of photogenerated electron-hole pairs caused by the peroxo groups on the Ti(OH)4 surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.