Balancing near-field enhancement and hot carrier injection: plasmonic photocatalysis in energy-transfer cascade assemblies

Photocatalysisstands as a very promisingalternativeto photovoltaicsin exploitingsolar energyand storingit inchemicalproductsthrougha single-stepprocess.A centralobstacleto its broad implementationis its low conversionefficiency,motivatingresearchin differentfields to bring about a breakthroughin this technology.Using plasmonicmaterialsto photosensitizetraditionalsemiconductorphotocatalystsis a popularstrategywhose full potentialis yet to be fully exploited.In this work, we useCdS quantumdots as a bridge system,reapingenergyfrom Au nanostructuresand deliveringit to TiO2nanoparticlesservingascatalyticcenters.The quantumdots can do this by becomingan intermediatestep in a charge-transfercascadeinitiatedin theplasmonicsystemor by creatingan electron−holepair at an improvedrate due to their interactionwith the enhancednear-fieldcreatedby the plasmonicnanoparticles.Our results show a significantaccelerationin the reactionupon combiningthese elementsinhybrid colloidalphotocatalyststhat promotethe role of the near-fieldenhancementeffect, and we show how to engineercomplexesexploitingthis approach.In doing so, we also explorethe complexinterplaybetweenthe differentmechanismsinvolvedin thephotocatalyticprocess,highlightingthe importanceof the Au nanoparticles’morphologyin their photosensitizingcapabilitiesMinisterio de Universidades | Ref. 33.50.460A.752Ministerio de Ciencia e Innovación | Ref. PDC2021-121787-I00Ministerio de Ciencia e Innovación | Ref. PID2020-113704RB-I00Ministerio de Ciencia e Innovación | Ref. PID2020-118282RA-I00Ministerio de Ciencia e Innovación | Ref. PID2020-120306RB-I00Ministerio de Ciencia e Innovación | Ref. RYC2021-033818-IMinisterio de Ciencia e Innovación | Ref. TED2021-130038A-I00Ministerio de Ciencia e Innovación | Ref. TED2021-132101B-I00Xunta de Galicia | Ref. IN607A 2018/5Generalitat de Catalunya | Ref. 2020SGR00166Centro Singular de Investigación de Galicia | Ref. ED431G 201906National Natural Science Foundation of China | Ref. 22250610200Universitat Rovira i Virgili | Ref. 2021PFR-URV-B2-02United States-Israel Binational Science Foundation | Ref. 2018050Universidade de Vigo/CISU

Synthesis of a mesoscale ordered 2D-conjugated polymer with semiconducting properties

2D materials with high charge carrier mobility and tunable electronic band gaps have attracted intense research effort for their potential use as active components in nanoelectronics. 2D-conjugated polymers (2DCP) constitute a promising sub-class due to the fact that the electronic band structure can be manipulated by varying the molecular building blocks, while at the same time preserving the key features of 2D materials such as Dirac cones and high charge mobility. The major challenge for their use in technological applications is to fabricate mesoscale ordered 2DCP networks since current synthetic routes yield only small domains with a high density of defects. Here we demonstrate the synthesis of a mesoscale ordered 2DCP with semiconducting properties and Dirac cone structures via Ullmann coupling on Au(111). This material has been obtained by combining rigid azatriangulene precursors and a hot dosing approach which favours molecular diffusion and reduces the formation of voids in the network. These results open opportunities for the synthesis of 2DCP Dirac cone materials and their integration into devices.Comment: 21 pages, 3 figure

Local growth mediated by plasmonic hot carriers: chirality from achiral nanocrystals using circularly polarized light

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGPlasmonic nanocrystals and their assemblies are excellent tools to create functional systems, including systems with strong chiral optical responses. Here we study the possibility of growing chiral plasmonic nanocrystals from strictly nonchiral seeds of different types by using circularly polarized light as the chirality-inducing mechanism. We present a novel theoretical methodology that simulates realistic nonlinear and inhomogeneous photogrowth processes in plasmonic nanocrystals, mediated by the excitation of hot carriers that can drive surface chemistry. We show the strongly anisotropic and chiral growth of oriented nanocrystals with lowered symmetry, with the striking feature that such chiral growth can appear even for nanocrystals with subwavelength sizes. Furthermore, we show that the chiral growth of nanocrystals in solution is fundamentally challenging. This work explores new ways of growing monolithic chiral plasmonic nanostructures and can be useful for the development of plasmonic photocatalysis and fabrication technologies.Xunta de Galicia | Ref. ED431C 2016-034Xunta de Galicia | IN607A 2018/5Agencia Estatal de Investigación | Ref. CTM2017-84050-RAgencia Estatal de Investigación | Ref. PID2020-113704RB-I00Agencia Estatal de Investigación | Ref. PID2020-118282RA-I0

Plasmonic Glasses and Films Based on Alternative Inexpensive Materials for Blocking Infrared Radiation

The need for energy-saving materials is pressing. This paper reports on the design of energy-saving glasses and films based on plasmonic composite glasses is nontrivial and requires to take full advantage of both materials and shape-related properties of the nanoparticles. We compute the performance of solar plasmonic glasses incorporating a transparent matrix and specially-shaped nanocrystals. Plasmonic nanoshells are shown to exhibit the best performances as compared to nanorods and nanocups. Simultaneously, the synthesis of plasmonic nanoshells is technologically feasible using gas-phase fabrication methods. The computational work was done for noble metals (Au, Ag) as well as for alternative plasmonic materials (Al, Cu, TiN). Inexpensive materials (Ag, Al, Cu, TiN) show overall good performance in terms of the commonly-used figures of merit of industrial glass windows. Together with numerical data for specific materials, this study includes a set of general rules for designing efficient plasmonic IR-blocking media. The plasmonic glasses proposed herein are good candidates for cheap optical media to be used in energy-saving windows in warm climates' housing or temperature-sensitive infrastructure