Facet‐Dependent and Light‐Assisted Efficient Hydrogen Evolution from Ammonia Borane Using Gold–Palladium Core–Shell Nanocatalysts

Abstract

Au-Pd core-shell nanocrystals with tetrahexahedral (THH), cubic, and octahedral shapes and comparable sizes were synthesized. Similar-sized Au and Pd cubes and octahedra were also prepared. These nanocrystals were used for the hydrogen-evolution reaction (HER) from ammonia borane. Light irradiation can enhance the reaction rate for all the catalysts. In particular, Au-Pd THH exposing {730} facets showed the highest turnover frequency for hydrogen evolution under light with 3-fold rate enhancement benefiting from lattice strain, modified surface electronic state, and a broader range of light absorption. Finite-difference time-domain (FDTD) simulations show a stronger electric field enhancement on Au-Pd core-shell THH than those on other Pd-containing nanocrystals. Light-assisted nitro reduction by ammonia borane on Au-Pd THH was also demonstrated. Au-Pd tetrahexahedra supported on activated carbon can act as a superior recyclable plasmonic photocatalyst for hydrogen evolution.

Serrated Au/Pd Core/Shell Nanowires with Jagged Edges for Boosting Liquid Fuel Electrooxidation

“…[5] Also, the catalytic activity and selectivityo fthe core/shell structure can be regulated by tailoring the morphology [6] and thickness [7] of the shell:t he morphology determines the exposed facets, and the thickness determines the modification of the inner core to the electronic state [7a, 8] and the lattice strain [7b, 8, 9] of outsides hell. Therefore, rationally designing shells of different morphologya nd thickness is vital for developing core/shell nanostructures into highly efficient catalysts.Among different types of core/shell structures, Au/Pd core/ shell nanostructures are one of most promising nanocatalysts for boosting the catalytic performance in organic synthesis, [6a] fuel cells, [6b, c] hydrogen production, [10] and analytical detection. [11] To date, Au/Pd core/shell nanostructures have been produced throughs eed-mediated growth, [6a, d, 10a, 11b, 12] successive reduction, [13] andc o-reduction [6c, 14] approaches.…”

“…Among different types of core/shell structures, Au/Pd core/ shell nanostructures are one of most promising nanocatalysts for boosting the catalytic performance in organic synthesis, [6a] fuel cells, [6b, c] hydrogen production, [10] and analytical detection. [11] To date, Au/Pd core/shell nanostructures have been produced throughs eed-mediated growth, [6a, d, 10a, 11b, 12] successive reduction, [13] andc o-reduction [6c, 14] approaches.…”

Donut Assembly of Nanoparticles with High Catalytic Efficiency for Hydrogen Gas Generation from Ammonia Borane

“…The presence of gold in these assemblies also promoted us to investigate the plasmonic resonance effect with the expectation that the local heating from gold NPs under light irradiation could speed up the AB decomposition, given the previously examples in which the plasmon effect of gold or silver increased the activity of close catalytic centers …”

“…The presence of gold in these assemblies also promoted us to investigate the plasmonic resonance effect with the expectation that the local heating from gold NPs under light irradiation could speed up the AB decomposition, given the previously examples in which the plasmon effect of gold or silver increased the activity of close catalytic centers. [43][44][45] In fact, the reaction conducted under the irradiation of white light exhibited the highest TOF reaching 980 min À 1 for CP1À Au 0.1 Rh 0.9 ( Figure 3A). The temperature of the reaction mixture measured the same as that in the dark reaction, and we speculated that in our case the LSPR effect enhanced the reaction rate in two ways including local thermal heating and charge separation.…”

In Situ Observations of Shell Growth and Oxidative Etching Behaviors of Pd Nanoparticles in Solutions by Liquid Cell Transmission Electron Microscopy

“…In the practical nanostructure synthesis and nanofabrication, it is sometimes desirable that the controllable shell growth or etching processes can occur in the same nanostructures. This will facilitate the manufacturing of complex nanostructures and expand their important applications . In this report, by taking Pd nanoparticles in Au salt (specifically HAuCl 4 ) solutions as an example, we performed systematic LCTEM investigations of the solution reaction characteristics with/without the presence of stabilizing agents.…”