Sustainable Energy: The Contribution of Photocatalysis and Photonics.
Principles, Properties and Applications

summer term 2017

Monday till Friday 18.9. - 29.9.17 8:15 to 9:45 in room NW2 C0300 (25th and 26th in C0290)

Prof. Dr. Cecilia B. Mendive
Laboratory of Photonic Photocatalysis
Department of Chemistry
Faculty of Exact and Natural Sciences
National University of Mar del Plata
-Visiting professor at Bremen Universitaet-


Due to limited energy resources of the planet, maximizing the potential use of solar light turns into a pressing need to meet the increasing demand. Thus, the synthesis and preparation of visible light photocatalysts is an undoubtedly interesting challenge not only from the fundamental point of view, but also a technological issue. Of particular importance is the case of nanoparticulate TiO2, which photocatalytic activity finds multiple applications, among others: air and water purification for environmental remediation, disinfection, technological solutions as self-cleaning or anti-fogging surfaces, and production of H2 by water splitting as an alternative clean fuel. But, as the practical use of TiO2 is limited because its absorption corresponds to a wavelength range within the UV spectrum of light, different and diverse are the efforts focused in modifying the system in order to make a more efficient use of the solar light. In this course, several techniques to extend its absorption to the visible region, spanning chemical and structural modifications will be revised: doping with foreign atoms, electronic coupling with noble metals, preparations of composites, and a quite recently developed technique that combines elements of photonics for an effective use of “slow photons”. An introduction to photonic crystals will cover basic definitions, such as the fundamentals of forbidden bands for photons, the origin of photonic band-gaps (PBG), and the description of the slow photons present in the systems. The practical work will therefore include the preparation and characterization of such structures. The work in the lab will focus on the critical points necessary to achieve a minimum concentration of defects that hinder the photonic properties of the crystals. Thus, additionally to the wet chemistry tools, advanced instrumental characterization will be employed, to finally test the photocatalytic activity of the prepared samples in order to identify the effect of the slow photons. The photonic efficiencies of the samples will be measured for the photocatalytic degradation of a model compound. Reactor parameters and surface chemistry mechanistic issues will be particularly considered.


• General introduction and motivation
• Introduction to the band structure of semiconductors
• Conductors, insulators and semiconductors
• Semiconductors and currents
• Semiconductors and light
• The principle of photocatalysis
• Titanium dioxide and its multiple applications
• Band gap tuning, methods and mechanisms
• A case study: “The deaggregation mechanism”
• Monte Carlo simulations for uncertainties estimations
• Introduction to photonic crystals
• The Maxell Equations and the theta operator
• Comparisons with quantum mechanics
• Photonic crystals and semiconductors
• Photonic photocatalysis: Slow photons
Scripts and more