Photocatalysis, A Laboratory Experiment for an Integrated Physical Chemistry-Instrumental Analysis Course

Abstract

The laboratory experiments described are intended for a junior-level integrated (Physical Chemistry–Instrumental Analysis) laboratory course. In these experiments, students explore various attributes of photocatalytic reactions, including kinetics and product characterization. The students may select the system they wish to study and the question they wish to investigate. This allows the project to be more open-ended than the typical laboratory. One system involves the solution-phase photocatalytic decomposition of benzoquinone or 2-chlorophenol using either TiO2 or ZnO as photocatalysts. In this series of experiments, the students may choose to compare photocatalysts to determine which catalyst is more effective or they may explore the kinetics of one reactant–photocatalyst combination. Another system for study is the gas-phase photocatalytic decomposition of trichloroethylene using TiO2 as the photocatalyst. This experiment requires the students to characterize the products of their photocatalytic reaction using FTIR and GC–MS. Thus the instructor and the students may select the portion of the experiment that best fits in with the students' and instructor's interests. Examples are included of student data collected from this experiment.

Demonstrating Online Monitoring of Air Pollutant Photodegradation in a 3D Printed Gas-Phase Photocatalysis Reactor

“…A visible color change of the solution is observed within 5 to 30 min, which can readily be quantified spectrophotometrically. 29 In contrast, tutorial demonstration of gas phase photocatalysis for educational purposes is more challenging and, as there is no visible change, advanced analytical equipment such as gas chromatography (GC), mass spectrometry (MS), GC−MS, or advanced IR spectroscopy setups is required, 30 which complicates online (in situ) analysis.…”

Photocatalytic Hydrogen Production over CdS Nanomaterials: An Interdisciplinary Experiment for Introducing Undergraduate Students to Photocatalysis and Analytical Chemistry

“…The concept and study of photocatalysis have also received increasing emphasis in undergraduate chemistry courses recently. Many teaching experiments and reactors about heterogeneous photocatalytic degradation and oxidation of pollutants have been reported, which help students to understand the basic chemistry, concepts, and extensive applications of semiconductors and photocatalysis. − For instance, Tatarko et al and Chen et al designed a cheap photocatalytic reactor and a simple parallel photochemical reactor for the remediation of the azo dye Congo Red and methylene blue in water for undergraduate students, respectively. , Boffa et al prepared sol–gel-derived TiO 2 powders for the photodegradation of toluidine blue in solution using UV–vis light, thus effectively introducing undergraduate students to materials chemistry . Pitcher et al described a simple demonstration of photocatalysis using the photodegradation of 2,6-dicholorophenolindophenol sodium salt (DCIP) over the commercially available TiO 2 .…”

Wetting Modification by Photocatalysis: A Hands-on Activity To Demonstrate Photoactivated Reactions at Semiconductor Surfaces

“…The application of photocatalysis to the tailoring of wetting phenomena is well suited to provide engaging activities for students of all levels, which can introduce the general concepts of photocatalysis in a more tangible and immediate/compelling way than conventional experiments such as pollutant degradation [7][8][9][10] . Moreover, very few works have proposed teaching laboratory activities on the modification of wetting properties of oxide materials by chemical [11][12][13] or physical 14 means.…”

“…The application of photocatalysis to the tailoring of wetting phenomena is well suited to provide engaging activities for students of all levels, which can introduce the general concepts of photocatalysis in a more tangible and immediate/compelling way than conventional experiments such as pollutant degradation. − Moreover, very few works have proposed teaching laboratory activities on the modification of wetting properties of oxide materials by chemical − or physical means. Physical chemistry courses for both Bachelor’s and Master’s students rarely deal with these concepts, and few practical experiences that can provide basic knowledge by adopting easy experimental procedures are reported.…”