Anran Li

Direct evidence of plasmon enhancement on photocatalytic hydrogen generation over Au/Pt-decorated TiO2 nanofibers.

Direct evidence of plasmon-enhanced H2 generation is observed in photocatalytic water reduction by using TiO2 electrospun nanofibers co-decorated with Au and Pt nanoparticles through dual-beam irradiation. The Au/Pt/TiO2 nanofibers exhibit certain activity for H2 generation under single irradiation at 420 nm that excites the defect/impurity states of TiO2. Significantly, when secondary irradiation at 550 nm is introduced to simultaneously excite Au SPR, we observed 2.5 times higher activity for H2 generation. Further investigation by finely controlling the irradiation wavelengths reveals that the enhancement factor on the photocatalytic activity for H2 generation is directly correlated with the plasmon absorption band of the Au nanoparticles in the Au/Pt/TiO2 nanofibers. The control experiments with different sacrificial agents suggest that the hot plasmonic electrons of Au are responsible for the enhanced photocatalytic activity that can be magnified when TiO2 is simultaneously excited.

Dually Ordered Porous TiO2-rGO Composites with Controllable Light Absorption Properties for Efficient Solar Energy Conversion

Quadruple-layered TiO2 films with controllable macropore size are prepared via a confinement self-assembly method. The inverse opal structure with ordered mesoporous (IOM) presents unique light reflection and scattering ability with different wavelengths. Cyan light (400-600 nm) is reflected and scattered by IOM-195, which is in accord with N719 absorption spectra. By manipulating the macropore size, different light responses are obtained.

Enhanced Photoresponse of Conductive Polymer Nanowires Embedded with Au Nanoparticles

A conductive polymer nanowire embedded with a 1D Au nanoparticle chain with defined size, shape, and interparticle distance is fabricated which demonstrates enhanced photoresponse behavior. The precise and controllable positioning of 1D Au nanoparticle chain in the conductive polymer nanowire plays a critical role in modulating the photoresponse behavior by excitation light wavelength or power due to the coupled-plasmon effect of 1D Au nanoparticle chain.

Gold mesoflowers with a high density of multilevel long sharp tips: synthesis and characterization

A one-step, aqueous-based, and surfactant-free method to synthesize gold mesoflowers (AuMFs) with multilevel long sharp tips is reported. The method enables control of the size, morphology, and optical properties of the AuMFs by tuning the reaction parameters such as concentration of precursor, halide, and reducing agent. The nanoparticle growth process is studied in detail and our findings suggest that chloride ions play a decisive role in the formation of long sharp tips and tip branching. The synthesized particles exhibit a tunable localized surface plasmon resonance (LSPR) response in the NIR and MIR regions (∼1800–3000 nm). These experimental observations are in agreement with simulations based on the finite-difference time-domain (FDTD) method. Moreover, the simulations also point towards a highly morphology-dependent field enhancement that opens up future applications of the AuMFs in surface-enhanced vibrational spectroscopy and sensing/therapeutics.

Polymer Nanowires: Enhanced Photoresponse of Conductive Polymer Nanowires Embedded with Au Nanoparticles (Adv. Mater. 15/2016)

A photoconductor based on composite conductive polymer nanowires embedded with one-dimensional gold nanoparticle chains is developed by L. Jiang, X. Chen, and co-workers, as shown on page 2978. The precise and controllable positioning of the nanoparticle array in the composite photoconductor endues a distinct plasmon-resonance-coupling effect, which plays a critical role in promoting and modulating the photoresponse behavior by the excitation-light wavelength or the power.