Can we realize the photocatalytic reaction driven by NIR light region? Who are the best candidates (TiO2, bimetallic doped or lanthanides) What are the major hurdles that should be overcome for the bright future of these phonon-photon interactions?
This question is kinda general, since the choice of an efficient photocatalyst depends on your system .There are three primary factors to be considered for the photocatalytic system.
1. Absorption and effective charge separation in NIR
2. Band edge positions of the photocatalyst relative to the system.
3. Stability
Now 1 is entirely dependent on your photocatalyst, its band gap and absorbance range. TiO2 is not a good choice since it has a band gap of 3.2 eV in UV. Lower band gap semiconductors are better options for NIR absorption. Look up a variety of Phopshides and Chalcogenides. Fullerenes also absorb in NIR.
2 and 3 depend on your system and their compatibility with the photo catalyst of choice. Say you want to use photocatalyst for water splitting, you need to make sure that the valance and conduction band edge positions reach up to the energy (or potential, on electrochemical terms) for oxygen evolution and and hydrogen evolution respectively. If this important criteria is not met, any amount of light absorption will be futile. Example, though hematite is active in visble region, it cannot produce hydrogen (only oxygen) since its conduction band edge does not surpass the hydrogen evolution potential. Dopants can shift the valance or conduction band edge positions, and what dopants you need to add depends on the reaction you aim to achieve by photocatalysis. Then, there are other things we need to focus on, such as lifetime of charge carriers and the issue of recombination. These can be resolved by adding supports and optimization. Last and most importantly, the photocatalyst must be stable in the system of choice.
Thank you, Arun. I shall take that into consideration. Can you suggest me on any papers considering NIR for photocatalyst. Hopefully, that will deepen my understanding.
please read one of our recent paper on the subject.
Infrared radiation active, novel nanocomposite photocatalyst for water splitting , in International Journal of Hydrogen Energy.
Thank you for the paper. Nice paper especially on performance. Just curious on the photocatalytic mechanism. Plus, is it possible to perform photocatalysis for dye degradation using the technique.
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