d–sp Interband Transition Excited Carriers Promoting the Photochemical Growth of Plasmonic Gold Nanoparticles
Jian Li, Qi Shen, Jin Li, Jing Liang, Kang Wang, Xing‐Hua Xia
Abstract
As an important damping way of the light absorption of plasmonic nanoparticles, the d-sp interband transition within the short wavelength regime has been recently drawing attentions in photochemistry. Compared with the intraband Landau damping, the d-sp interband transition excited carriers have larger populations and longer relaxation times, which is promising to match the photochemical reactions in time scale. Here, we propose a novel approach to the growth of plasmonic gold nanoparticles more efficiently promoted by d-sp interband transition excited charge carriers than by plasmon excited carriers. It is founded that photochemical growth of plasmonic gold nanoparticles can be modulated by engineering the electrochemical potential of precursor using different surfactants. From the distribution of surfactant on a single gold nanoparticle revealed by nanoscale resolved IR mapping, a reasonable photochemical reaction mechanism mediated by d-sp interband excitation is suggested. The results highlight the importance of d-sp interband transition excited carriers in photochemical reactions especially for materials science.