Photooxidation of Water with Thin Film Tungsten Oxides

Abstract

Tungsten oxide semiconductors are used to photooxidize water. Students prepare WO 3 , CuWO 4 , and mixed composition thin film photoanodes. The syntheses are simple, allowing for the quick production of a range of materials. Photoanodes are tested in a photoelectrochemical cell assembled from common equipment, allowing for the direct comparison of photoanode performance. Composite photoanodes perform best, leading to a discussion of what limits overall performance in these materials. Additional instrumental methods such as SEM, EDS, XRD, and diffuse reflectance UV−vis spectrophotometry, if available, can be incorporated readily into the experiment, providing additional insights into material properties. Students are introduced to solid-state chemistry, semiconductors, and the photooxidation of water in the context of the hydrogen economy.

Teaching Heterogeneous Electrocatalytic Water Oxidation with Nickel- and Cobalt-Based Catalysts Using Cyclic Voltammetry and Python Simulation

“…Although different concepts of electrochemistry are taught in courses such as general chemistry, inorganic chemistry, analytical chemistry, and physical chemistry, experimental techniques of electrochemistry are not often applied in laboratory courses . Since it is challenging to provide students a comprehensive understanding of electrochemistry solely with lectures, more and more laboratory experiments and simulation tools have been developed in the past few years to promote hands-on experience in electrochemistry education. ,− Water electrolysis has recently been incorporated into the teaching laboratory curriculum as an introduction module to electrochemistry . Water electrolysis also serves as a model system for comprehending its side reactions, its implementation via photoelectrochemical (PEC) process as well as the spectroelectrochemistry technique .…”

“…6,8−19 Water electrolysis has recently been incorporated into the teaching laboratory curriculum as an introduction module to electrochemistry. 6 Water electrolysis also serves as a model system for comprehending its side reactions, 8 its implementation via photoelectrochemical (PEC) process 11 as well as the spectroelectrochemistry technique. 9 Several activities were also developed to teach the important fundamental concepts in electrochemistry such as electrode kinetics and mass transfer to undergraduate students.…”

Preparing GQDs/NiAl-LDH Composites and Investigating the Photocatalytic CO2 Reduction Performance: An Undergraduate Laboratory Experiment

“…The exploitation of efficient, cheap, and stable photocatalysts is still the priority of research, so early exposure to laboratories and chemical experiments can help undergraduates participate in research . Though similar teaching experiments have been published in this Journal , including electrochemical reduction of CO 2 and photooxidation of water, the emphasis of this experiment is to develop students’ practical ability and the capacity to analyze the internal mechanism.…”

Photocatalytic Hydrogen Evolution Using ZnS Particles and LEDs

“…Many educational publications have already addressed hydrogen evolution and water splitting. However, most of them presented electrolysis or photoelectrolysis experiments in which, in contrast to photocatalytic hydrogen evolution, external voltage was applied and the photocurrent was measured. , Previously published photocatalysis experiments mainly focused on photocatalytic degradation. − For example, water was decontaminated by the photocatalytic degradation of dyes or other water contaminating organic compounds. Photocatalytic hydrogen generation experiments are relatively rare. − Zhang et al performed one with TiO 2 nanoparticles and monitored it with an oxygen sensor .…”

“…However, most of them presented electrolysis or photoelectrolysis experiments in which, in contrast to photocatalytic hydrogen evolution, external voltage was applied and the photocurrent was measured. 3,4 Previously published photocatalysis experiments mainly focused on photocatalytic degradation. 5−16 For example, water was decontaminated by the photocatalytic degradation of dyes or other water contaminating organic compounds.…”