title: Superresolution fluorescence mapping of single-nanoparticle catalysts reveals spatiotemporal variations in surface reactivity.
abstract: For the practical application of nanocatalysts, it is desirable to understand the spatiotemporal fluctuations of nanocatalytic activity at the single-nanoparticle level. Here we use time-lapsed superresolution mapping of single-molecule catalysis events on individual nanoparticles to observe time-varying changes in the spatial distribution of catalysis events on Sb-doped TiO2 nanorods and Au triangle nanoplates. Compared with the active sites on well-defined surface facets, the defects of the nanoparticle catalysts possess higher intrinsic reactivity but lower stability. Corners and ends are more reactive but also less stable than flat surfaces. Averaged over time, the most stable sites dominate the total apparent activity of single nanocatalysts. However, the active sites with higher intrinsic activity but lower stability show activity at earlier time points before deactivating. Unexpectedly, some active sites are found to recover their activity ("self-healing") after deactivation, which is probably due to desorption of the adsorbate. Our superresolution measurement of different types of active catalytic sites, over both space and time, leads to a more comprehensive understanding of reactivity patterns and may enable the design of new and more productive heterogeneous catalysts.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China; Jilin Province Key Laboratory of Low Carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China;
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Mechanical Engineering, University of California at Berkeley, CA 94720; Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
authors.forename: J Matthew
authors.initials: JM
authors.lastname: Lucas
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China; Jilin Province Key Laboratory of Low Carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China;
authors.forename: Ping
authors.initials: P
authors.lastname: Song
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Materials Science and Engineering, University of California at Berkeley, CA 94720;
authors.forename: Brandon
authors.initials: B
authors.lastname: Beberwyck
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China; Jilin Province Key Laboratory of Low Carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China;
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China; Jilin Province Key Laboratory of Low Carbon Chemical Power, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, People's Republic of China; weilinxu@ciac.ac.cn alivis@berkeley.edu.
authors.forename: Weilin
authors.initials: W
authors.lastname: Xu
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720; Department of Chemistry, University of California at Berkeley, CA 94720; Kavli Energy Nano Science Institute, University of California, Berkeley, CA 94720 weilinxu@ciac.ac.cn alivis@berkeley.edu.
authors.forename: A Paul
authors.initials: AP
authors.lastname: Alivisatos
keywords: optical superresolution imaging; photocatalysis; single-molecule nanocatalysis; surface restructuring