After fabrication, the photothermally active silica monoliths undergo several stages of characterization. In addition to morphological, mechanical, optical, CO₂ adsorption capacity, surface area, and stability analyses, a key step is the evaluation of their photothermal performance.
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Photothermal characterization using narrowband light sources (image above:
The sample is illuminated from both sides with narrowband lights, and its photothermal response is evaluated using an HD-IR thermal camera (for surface temperature monitoring) and an optical probe positioned at the center of the monolith.
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Heating under conventional conditions (standard temperature swing method):
The monolith is placed in a box furnace and heated to a predefined temperature, while its surface temperature is monitored using an HD-IR thermal camera (middle image). The resulting temperature profiles are compared to the photothermal experiment using narrowband lights and therefore for estimate the energy required to reach the temperature necessary for complete CO₂ desorption.
3. In-situ/real-time photothermally triggered CO₂ desorption:
The optical setup is integrated around the sorbent analyzer system (above left image). During CO₂ adsorption at different pressures, the light source is periodically switched on and off, inducing photothermal desorption of CO₂ (above right image).