Adsorption technology is used to treat VOCs (Volatile Organic Compounds) and is considered one of the primary technologies for its treatment. In the past, MOFs (Metal-Organic Frameworks) have been in the limelight due to their amazing absorption abilities. LDHs (Layered Double Hydroxides) are closely related to MOFs, also referred to as hydrotalcite-like systems or anionic clays have also been at the end of special attention for their enhanced absorption characteristics. This is because of their enhanced porosity and chemical affinity at distinct active sites.
A SERS (Surface-Enhanced Raman Spectroscopy) gas sensor was developed by a research team that can easily detect aldehyde with high sensitivity and selectivity. This is a big advancement for Oil Gas Sensors Market as it will provide scientists with a new detection method to further their studies on the adsorption of gas molecules on porous materials. The research provides evidence that the SERS sensor has ultra-high sensitivity for aldehyde gas and has several advantages: selectivity, repeatability, and accuracy.
In the present study, composite nanomaterials (Co-Ni LDH ) and silver nanocubes (AgNCs) were arranged in the template sacrifice method. They were modified with 4-aminophenol (4-ATP) for both functions of trapping and probe. On the basis of prepared composite material, the research team built a high-efficiency gas sensor for detecting the aldehyde gas.
The experiments proved that the SERS sensor could be verified to be a great achievement. Together with the principal component analysis method, the team was able to identify and analyze the similar SERS spectrum of aldehyde gas through the sensor proving the application value.
A further investigation helped on the absorption kinetics and thermodynamic process of benzaldehyde molecules on Co-Ni LDH with the help of the sensor. The kinetic process would be better fitted if the pseudo-first-order-kinetics with a better correlation coefficient would be used instead of a pseudo-second-order model. The isotherm absorption matches the Langmuir isotherm model. Its adsorption constant is known to be 6.25 × 106 L/mol, which proves that the adsorption sites of the composites are homogenous and largely dominated by monolayer chemisorption.
The study is immensely beneficial and would be able to establish a new measurement method for probing the adsorption process with very low consumption levels of both adsorbents and adsorbates. Furthermore, it might also lay down the foundational work for constructing rapid and ultra-sensitive SERS sensors penetrating VOCs in the future.