Photoelectrocatalytic hydrogen production with TiO2 nanostructures formed by alternating voltage anodization

Abstract. A photoelectrocatalytic (PEC) cell uses solar light to split the water in hydrogen and oxygen. The hydrogen is a green fuel, delivers more energy than gasoline (per unit mass) and during its combustion only water is generated. The splitting of the water molecule is achieved in a PEC cell when light interacts with a photoactive semiconductor, oxidative and reductive species are generated. Nevertheless, in its current state, the PEC technology generates hydrogen at a cost 3 to 5 times higher than the target cost for industrial operation, and demands an additional electrical power input to operate at maximum efficiency. Two strategies are commonly used to reduce the operational cost of the PEC cell, first to increase the efficiency of the photoactive semiconductor, and second to supply the demanded electrical power from alternative and cost-effective energy sources. In this thesis TiO2 nanotubes prepared by anodization are used as photoanode in a PEC cell. The nanotube morphology: tube length, diameter and the number of rings on the external wall, is studied in order to increase the PEC efficiency of the material. Also, the PEC cell with nanotubes of optimized morphology is coupled to two different alternative electricity generation systems in order to provide the demanded electrical power. One of those systems removes organic pollutants from wastewater and uses light to generate the electrical power (photo-fuel cell, PFC), and the second system uses the potential generated naturally between atmospheric clouds and the Earth’s surface (harvesting of the corona effect). When coupled, the PEC cell was able to produce hydrogen independently from the power grid.

• Autores: Arias Monje, Pedro Jose
• Fecha de publicación: 2016
• Institución: Universidad Nacional de Colombia
• Repositorio: Universidad Nacional de Colombia
• Idioma: spa
• OAI Identifier: oai:repositorio.unal.edu.co:unal/56792
• Acceso en línea: https://repositorio.unal.edu.co/handle/unal/56792; http://bdigital.unal.edu.co/52732/
• Palabra clave: 6 Tecnología (ciencias aplicadas) / Technology; 66 Ingeniería química y Tecnologías relacionadas/ Chemical engineering; Photoelectrocatalytic (PEC) cell; water splitting; TiO2 nanotubes; Anodization; Photo-fuel cell (PFC); Corona current; Celda Fotoelectrocatalítica (PEC cell); Separación de la molécula de agua; Nanotubos de TiO2; Anodización; Foto celda de combustible (PFC); Corriente corona
• Rights: openAccess
• License: Atribución-NoComercial 4.0 Internacional