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• Multiphysics modeling of fluid flow, heat and mass transport, and electrochemistry. • Simulation gives in-depth information about plasmonic heated electrochemical system. • Electrochemistry experiments confirmed quantitative relations found by simulation. • Rotating disk electrode shows linear response under the effect of plasmonic heating. Plasmon-mediated chemical reaction (PMCR) is an emerging research field recently, with potential applications in solar energy conversion such as water splitting and CO 2 reduction. However, the exact mechanism of PMCR is still not fully understood mainly because the plasmonic heating effect and generation of energized charge carriers can both accelerate chemical reactions. It remains a challenge to quantitatively distinguish the plasmonic heating's contribution from overall plasmonic catalysis effect. To solve this problem, in this paper we utilized a strategy of combined multiphysics numerical simulation and photoelectrochemical experiment to qualitatively characterize the plasmonic heating-induced change of electrochemical response, as well as explain the mechanism behind such change, especially on the rotating disk electrode system which is commonly used in electrocatalysis research. Finite element method was used to solve the numerical model while ferricyanide oxidation was used as a probe reaction. Heat transfer, fluid flow, mass transfer, and electrode kinetics were modeled into the theoretical framework, showing convective flow near plasmonic heated electrode plays a crucial role both in terms of heat dissipation and electroactive species transportation. Simulated intermittent light chronoamperometry shows an exponential current onset process caused by plasmonic heating. For the rotating disk electrode system, a linear relationship of illuminating light power-limiting current was discovered, explained by simulation results, and confirmed by photoelectrochemical experiments. This comprehensive investigation is beneficial for future research on the mechanism of PMCR and photoelectrochemical catalysis. [Display omitted] [ABSTRACT FROM AUTHOR]

With the ever-growing demand in fresh water supply, great efforts have been devoted to developing sustainable systems which could generate fresh water continuously. Solar vapor generation is one of the promising strategies which comprise an unlimited energy source and efficient solar-to-heat generators for overcoming fresh water scarcity. However, current solar vapor generation systems suffer either from inefficient utilization of solar energy or an expensive fabrication process. In this paper, we introduced a nano-plasmonic approach, i.e., a floatable nanocompoiste where copper sulfide nanorods (Cu2-xS NRs) are embedded in a polyvinyl alcohol (PVA) matrix, for solar-to-vapor generation. A high solar vapor generation efficiency of ~87% and water evaporation rate of 1.270 kg m−2 h−1 were achieved under simulated solar irradiation of 1 sun. With the illumination of natural daylight, seawater was purified using Cu2-xS NRs-PVA gel, with high purity, as distilled drinking water. The plasmonic nanocomposites demonstrated here are easy to fabricate and highly efficient for solar vapor generation, illustrating a potential solution for future seawater desalination. [ABSTRACT FROM AUTHOR]

Atmospheric frosting and icing pose significant problems for critical and common-use infrastructures. Passive anti-frosting and anti-icing strategies that require no energy input have been actively sought, with no viable and permanent solutions known yet. Bioinspired superhydrophobic (SH) materials have been considered promising path to explore; however, the outcome has been less than compelling because of their low resistance to atmospheric humidity. In most cases, condensing water on an SH surface eventually leads to mechanical locking of ice instead of ice removal. Hybrid strategies involving some form of limited energy input are being increasingly considered, each with its own challenges. Here, we propose the application of plasmonic heating of silver nanowires (AgNWs) for remote frost removal, utilizing an SH hybrid passive-active system. This novel system comprises a durable nanocomposite covered with a hydrophobized mesh of AgNWs, protected against environmental degradation by a tin oxide (SnO2) shell. We demonstrate the frost removal ability at âˆ'10 °C and 30% RH, achieved by a combination of plasmonic heating of AgNWs with a non-sticking behavior of submicrometric droplets of molten frost on the SH surface. Heating was realized by illuminating the mesh with low-power blue laser light. Adjustment of the nanowire (NW) and shell dimensions allows the generation of surface plasmon resonance in illuminated NWs at a wavelength overlapping the emission maximum of the light used. In environmental stability tests, the nanostructures exhibited high atmospheric, mechanical, and thermal stability. The narrow-wavelength absorption of the structure in the blue light range and the reflective properties in the infrared range were designed to prevent protected surfaces from overheating in direct sunlight. [ABSTRACT FROM AUTHOR]

A stimuli-responsive (pH- and thermoresponsive) micelle-forming diblock copolymer, poly(1,2-butadiene)290-block-poly(N,N-dimethylaminoethyl methacrylate)240 (PB-b-PDMAEMA), was used as a polymer template for the in situ synthesis of silver nanoparticles (AgNPs) through Ag+ complexation with PDMAEMA blocks, followed by the reduction of the bound Ag+ with sodium borohydride. A successful synthesis of the AgNPs on a PB-b-PDMAEMA micellar template was confirmed by means of UV–Vis spectroscopy and transmission electron microscopy, wherein the shape and size of the AgNPs were determined. A phase transition of the polymer matrix in the AgNPs/PB-b-PDMAEMA metallopolymer hybrids, which results from a collapse and aggregation of PDMAEMA blocks, was manifested by changes in the transmittance of their aqueous solutions as a function of temperature. A SERS reporting probe, 4-mercaptophenylboronic acid (4-MPBA), was used to demonstrate a laser-induced enhancement of the SERS signal observed under constant laser irradiation. The local heating of the AgNPs/PB-b-PDMAEMA sample in the laser spot is thought to be responsible for the triggered SERS effect, which is caused by the approaching of AgNPs and the generation of "hot spots" under a thermo-induced collapse and the aggregation of the PDMAEMA blocks of the polymer matrix. The triggered SERS effect depends on the time of a laser exposure and on the concentration of 4-MPBA. Possible mechanisms of the laser-induced heating for the AgNPs/PB-b-PDMAEMA metallopolymer hybrids are discussed. [ABSTRACT FROM AUTHOR]

Plasmonic nanoheating can be utilized to induce nanophase transformation, which has important implications for nano‐optoelectronics, nano‐piezoelectronics, and high‐density data storage. Herein, optical poling of poly(vinyl difluoride) (PVDF) is shown with the assistance of surface plasmons. The ultrathin PVDF films are sandwiched between gold nanoparticles (Au NPs) and a gold film. By irradiating the Au NPs with continuous‐wave laser, nanoannealing of the PVDF films is realized, which locally transforms the PVDF from α phase to β phase as evidenced by Raman spectroscopy. This nanophase transformation is reproducible and scalable by scanning laser across the Au NP films deposited on the PVDF. In such a way, arbitrary patterns of β phases can be generated, which can potentially be applied for integrated piezoelectronic devices, high‐density data storage, and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Controlled manipulation of nanoscale objects in fluids is relevant to both fundamental studies and technological advances in nanotechnology. While standard techniques of nanomanipulation, such as optical and plasmonic tweezers have limitations in simultaneous trapping and transport of nanoscale cargo, magnetically driven plasmonic nanorobots under optical illumination provide a promising solution. These so called mobile nanotweezers (MNT) use strongly localized electromagnetic field near plasmonic nanostructures to trap objects with high efficiency and can simultaneously be driven by magnetic fields to selectively trap, transport and release colloidal cargo. Upon illumination, apart from strong optical gradient forces due to local electric field enhancement, additional fluidic forces arise due to the heat generated by absorption of light. Here, we present a method to understand and engineer thermally induced fluidic forces in mobile nanotweezers. The temperature enhancement and associated thermofluidic forces are studied as a function of MNT geometry. We also discuss illumination at wavelengths slightly detuned from plasmon resonance frequency, which produces sufficient field enhancement with negligible generation of heat, and therefore much reduced thermophoretic and convective forces. This allowed us to engineer thermoplasmonic forces in MNTs for enhanced trapping performance and diverse applications. [ABSTRACT FROM AUTHOR]

Heterogeneous bubble nucleation is one of the most fundamental interfacial processes that has received broad interest from diverse fields of physics and chemistry. While most studies focused on large microbubbles, here we employed a surface plasmon resonance microscopy to measure the nucleation rate constant and activation energy barrier of single nanosized embryo vapor bubbles upon heating a flat gold film with a focused laser beam. Image analysis allowed for simultaneously determining the local temperature and local nucleation rate constant from the same batch of optical images. By analyzing the dependence of nucleation rate constant on temperature, we were able to calculate the local activation energy barrier within a submicrometer spot. Scanning the substrate further led to a nucleation rate map with a spatial resolution of 100 nm, which revealed no correlation with the local roughness. These results indicate that facet structure and surface chemistry, rather than geometrical roughness, regulated the activation energy barrier for heterogeneous nucleation of embryo nanobubbles. [ABSTRACT FROM AUTHOR]

With the ever-growing demand in fresh water supply, great efforts have been devoted to developing sustainable systems which could generate fresh water continuously. Solar vapor generation is one of the promising strategies which comprise an unlimited energy source and efficient solar-to-heat generators for overcoming fresh water scarcity. However, current solar vapor generation systems suffer either from inefficient utilization of solar energy or an expensive fabrication process. In this paper, we introduced a nano-plasmonic approach, i.e., a floatable nanocompoiste where copper sulfide nanorods (Cu2-xS NRs) are embedded in a polyvinyl alcohol (PVA) matrix, for solar-to-vapor generation. A high solar vapor generation efficiency of ~87% and water evaporation rate of 1.270 kg m−2 h−1 were achieved under simulated solar irradiation of 1 sun. With the illumination of natural daylight, seawater was purified using Cu2-xS NRs-PVA gel, with high purity, as distilled drinking water. The plasmonic nanocomposites demonstrated here are easy to fabricate and highly efficient for solar vapor generation, illustrating a potential solution for future seawater desalination.

Whereas the application of optically or magnetically heated nanoparticles to destroy tumours is now well established, the extension of this concept to target pathogens has barely begun. Here we examine the challenge of targeting pathogens by this means and, in particular, explore the issues of power density and heat transfer. Depending on the rate of heating, either hyperthermia or thermoablation may occur. This division of the field is fundamental and implies very different sources of excitation and heat transfer for the two modes, and different strategies for their clinical application. Heating by isolated nanoparticles and by agglomerates of nanoparticles is compared: hyperthermia is much more readily achieved with agglomerates and for large target volumes, a factor which favours magnetic excitation and moderate power densities. In contrast, destruction of planktonic pathogens is best achieved by localised thermoablation and very high power density, a scenario that is best delivered by pulsed optical excitation. [ABSTRACT FROM AUTHOR]

The selective modification of silica/gold nanospheres (gold nanoshells) driven by plasmonic heating is demonstrated. Direct laser writing and reshaping of nanoshell assemblies can be easily controlled and exploited for nanofabrication purposes. The modified nanoshells exhibit improved surface enhanced Raman scattering, allowing to settle most of the issues related to nanoshell stability under working conditions. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We developed a complex three-dimensional (3D) multilayer deposition method for the fabrication of single-walled carbon nanotubes (SWCNTs) using vacuum filtration and plasmonic carbonization without lithography and etching processes. Using this fabrication method, SWCNTs can be stacked to form complex 3D structures that have a large surface area relative to the unit volume compared to the single-plane structure of conventional SWCNTs. We characterized 3D multilayer SWCNT patterns using a surface optical profiler, Raman spectroscopy, sheet resistance, scanning electron microscopy, and contact angle measurements. Additionally, these carbon nanotube (CNT) patterns showed excellent mechanical stability even after elastic bending tests more than 1000 times at a radius of 2 mm. [ABSTRACT FROM AUTHOR]