Global warming is a serious threat to the planet and the living beings. The increase in the atmospheric CO2 level is one of the leading causes of global warming. The primary source of this CO2 is from the burning of fossil fuels in daily lives, including electricity, vehicles, industry, and many more.
The TIFR researchers have created the solution phase synthesis of Dendritic Plasmonic Colloidosomes (DPCs) with varying interparticle distances between the gold Nanoparticles (NPs) using a cycle-by-cycle growth approach by optimizing the nucleation-growth step. These DPCs absorbed the entire visible and near-infrared region of solar light, due to interparticle plasmonic coupling as well as the heterogeneity in the Au NP sizes which transformed golden gold material to black gold.
With the use of solar energy, black (nano) gold was able to catalyze CO2 to methane (fuel) conversion at atmospheric pressure and temperature. Also, the team observed the significant effect of the plasmonic hotspots on the performance of these DPCs for the purification of seawater to drinkable water through steam generation; temperature jump assisted protein unfolding, oxidation of cinnamyl alcohol using pure oxygen as the oxidant, and hydrosilylation of aldehydes.
In these DPCs, there was an attribution to varying interparticle distances and particle sizes. The outcomes indicate the synergistic effects of EM and thermal hotspots as well as hot electrons on DPCs performance. Thus, DPCs catalysts can effectively be utilized as Vis-NIR light photo-catalysts, and the design of new plasmonic nanocatalysts for a wide range of other chemical reactions may be possible using the concept of plasmonic coupling.
Surface-enhanced Raman Spectroscopy, SERS, and Raman thermometry offer information about the thermal and electromagnetic hotspots and local temperatures which was found to be dependent on the interparticle plasmonic coupling. The spatial distribution of the localized surface Plasmon modes by STEM-EELS Plasmon mapping confirmed the role of the interparticle distance in the SPR (Surface Plasmon Resonance) of the material.
Therefore, with this research, by utilizing the methods of nanotechnology, the researchers transformed golden gold to black gold by changing the size and gaps between gold nanoparticles. With the same effect to the real trees which use CO2, sunlight, and water to produce a fuel which can be used to run the cars. Notably, black gold can also be used to convert sea water into drinkable water using the heat that black gold generates after it captures sunlight.
This study initiates a way forward to develop "Artificial Trees," which capture and convert CO2 to fuel and useful chemicals. Even when the production rate of fuel is low at this stage, in the future, these challenges can be resolved. It may be possible to convert CO2 to fuel using sunlight at atmospheric condition, at a commercially viable scale and CO2 may then become our primary source of clean energy.
