Nanomaterials and Their Surface Chemistry: Manipulating Catalytic Efficiency through Quantum Dots
https://doi.org/10.5281/zenodo.19890383
Keywords:
Quantum Dots (QDs), Surface Chemistry Modification, Heteroatom Doping, Photocatalysis, Hydrogen Evolution Reaction (HER), Electrocatalytic CO₂ Reduction, Ligand Engineering, Defect Engineering, Core–Shell Nanostructures, Carbon Quantum Dots (CQDs).Abstract
The question of quantum dots (QDs) has turned out to be highly viable nanocatalysts in various processes such as electrocatalysis, photocatalysis, and environmental remediation since their surface chemistry can be altered and they can be confined to a small area. Their performance as catalysts is strongly influenced by surface structure, their interactions with the ligands, and defect states. Enhancement of surface functions can increase catalytic reactions by 63.2 percent relative to those that have not been modified. As an illustration, the electron transfer rate constant (k 3) is 3.4 x 10 -3 s -1 but it changes to 9.1 x 10 -3 s -1 upon the addition of nitrogen to carbon quantum dots (CQDs). This increases surface-mediated charge transport by 2.67. The mathematical model demonstrates that the addition of artificial surface states boosts the catalytic turnover frequency (TOF).
The rate of the adsorption is known as kads and 0active is the proportion of active surface sites. Kd [S] is a constant that informs you of the amount of the surface reactant that is available. It has been found that surface ligand exchange reaction especially that of thioglycolic acid by insulating oleylamine leads to an improvement in hydrogen evolution rate by 72 percent on exposure to visible light. This is mostly because the separation of charge carriers has gotten better, and the losses from interfacial recombination have gotten smaller.
Moreover, experimental results demonstrate that quantum dots (QDs) with elevated defect density produce mid-gap states, leading to a decrease in activation energy (Ea) by approximately 0.31 eV and promoting enhanced photocatalytic reaction rates. The addition of surface groups with sulphur increased the quantum yield for the photocatalytic breakdown of methylene blue from 11.5% to 33.9%. This shows how important it is to add heteroatoms to functional groups.
This study systematically investigates the utilisation of surface chemistry engineering to augment the catalytic efficiency of quantum dots through both mathematical and experimental methodologies. It also suggests predictive models that connect electron mobility with ligand structure, making it easier to systematically design QDs that work better for energy and environmental uses by more than 50%.
