IUNAT: Photocatalysis and Spectroscopy for Environmental Applications

Affiliated Research areas

• Structural properties of materials
• Mechanical engineering
• Individuals, Markets and Organisations
• Social aspects of teaching and learning, curriculum studies, education and educational policies

Scientific Areas

• Not available

Keywords

• Wetlands
• Wastewaters
• Computational chemistry
• Chemometry
• Heterogeneous photocatalysis
• TiO2
• Semiconductor synthesis
• Synthesis
• Hydrogen production
• Adsorption
• Biochar
• Removal pollutants
• Materials characterisation
• Synthesis of carbons
• Heterogeneous photocatalysis

Summary

- Development and characterization of adsorbent materials and their environmental application: This line focuses on: (1) Obtaining carbon-based materials such as biochar and activated carbons from the transformation of waste to be revalued, from biomass remains or from any precursor suitable for transformation; (2) Application of these materials in processes of environmental interest, alone in adsorption processes or combined with other materials for other processes such as photocatalytic processes; (3) Characterisation of this type of materials.
- Synthesis and characterization of materials for hydrogen production by heterogeneous photocatalysis: Synthesis of materials by solvothermal processes, sol-gel, impregnation and photodeposition. Characterization of these materials using the techniques available by the FEAM group (XRD, SEM-EDX, Raman and FTIR) and those of access through the Institute of Materials Science of Seville (BET, TG-DTA, TEM, XPS). Testing of these materials in hydrogen production in continuous systems with detection and quantification by gas microchromatography.
- Photocatalysis in environmental processes: The Photocatalysis uses light (UV spectra) absorbed by a semiconductor, which is in contact with an aqueous or gaseous dissolved organic pollutants or heavy metals in the presence of oxygen, to cause an oxidation-reduction reaction that can mineralize these pollutants to CO2 and water and / or recover the metal. A feature of this process is the presence of a Photocatalyst (semiconductor), which absorb solar radiation to produce oxidizing and reducing species (electrons and holes free surface). Titanium dioxide (TiO2) is the semiconductor most used, it is nontoxic, chemically stable, cheap and abundant and commonly used as a pigment in paint manufacture. The photocatalytic detoxification system is composed by an irradiated semiconductor which is in contact with the solution containing toxic agents. The TiO2 has the disadvantage that it takes a small part of the solar spectrum, UV radiation (λ = 380 nm). Our group investigates the improvement of Photocatalyst (TiO2) in order to maximize natural light and improve the decantability for recovery and reuse.
- Spectroscopy applied to the environment: Fourier Transform Infrared Spectrophotometry (FTIR) is a technique that allows the monitoring of chemical-physical interactions that occur on the surface of the photocatalyst between contaminants and the semiconductor solid. The technique is based on the use of infrared radiation that excites the vibro-rotational levels at the molecular level. The analysis of the obtained interferograms allows us to detect how the contaminating species are distributed on the surface of the semiconductor, and what is the chemical or physical nature of the interaction. The analysis also allows us to observe the changes produced in them, when we apply light, that is, when we carry out photocatalytic processes. This surface information controls the process of contaminant degradation in the solid, which complements the information extracted from the liquid or gas, depending on whether the advanced oxidation technique is applied to contaminants carried in the liquid or gas phase.
- Incorporation, optimization and development of instrumental physical-chemical techniques: The objective of this line of research is the incorporation, adaptation, optimisation and development of appropriate instrumental techniques for the characterisation of materials of photocatalytic interest, as well as for the monitoring and determination of organic and inorganic pollutants in the environment and their intermediates derived from photocatalytic application.
- Theoretical chemistry applied to catalysis and synthesis processes within green chemistry (sustainable): Theoretical Chemistry applied to Catalysis and synthesis processes within Green Chemistry (sustainable)
- Natural wastewater treatments: In the Canary Islands, water has been a cause of concern for its inhabitants, and has become more valuable to an eminently rural society than the land itself. In medium and small populations, natural or low-cost treatment systems emerge as viable and sustainable alternatives. The advantages of these purification systems are low energy consumption, reduction of microorganisms that indicate faecal contamination, low maintenance and operating costs, and positive ecological and visual impact. The land requirement is a disadvantage of these wastewater treatment systems. Our group has the following objectives: To determine the applicability of these systems in wastewater treatment in the Canary Islands, managing and studying a natural wastewater treatment plant located in the Tafira Campus of the ULPGC. To determine its capacity for the treatment of hazardous waste, water contaminated with solvents and organic compounds. Collaborate with research groups, combining natural treatment techniques with advanced oxidation techniques (solar photocatalysis) in order to increase their efficiency.