Plasmonic MOF for Highly Selective SERS Sensing of Trace Mercury (II) in Complex Matrices.

Developing Ag-based surface-enhanced Raman spectroscopy (SERS) sensors for detecting Hg(II) has garnered significant research interest due to their unparalleled selectivity, which is brought by the specific Ag-Hg amalgamation reaction. However, existing sensors perform unsatisfactorily in the trace detection of Hg(II) because the low concentration of Hg(II) does not have the redox potential sufficient to amalgamate with Ag. To address this challenge, a plasmonic MOF SERS sensor is developed, nanoetched Ag@UiO-68-SMe, by integrating the enormous Raman enhancement effects of nanoetched Ag with the selective enrichment function of UiO-68-SMe into single entity.

Single-Particle Imaging Photoinduced Charge Transfer of Ferroelectric Polarized Heterostructures for Photocatalysis.

Piezoelectric-assisted photocatalysis has a huge potential in solving the energy shortage and environmental pollution problems, and imaging their detailed charge-transfer process can provide in-depth understanding for the development of high-active piezo-photocatalysts; however, it is still challenging. Herein, topotactic heterostructures of TiO@BaTiO (TO@BTO-S) were constructed by the epitaxial growth of ferroelectric BaTiO mesocrystals on TiO-{001} facets, resulting in a ferroelectric photocatalyst with a polarization orientation on the surface. Notably, the photoinduced charge transfer in ferroelectric TiO@BaTiO was accurately monitored and directly visualized at the single-particle level by the advanced photoluminescence (PL) imaging microscopy systems.

Full-spectrum plasmonic semiconductors for photocatalysis.

Localized surface plasmon resonance (LSPR) of noble metal nanoparticles can focus surrounding light onto the particle surface to boost photochemical reactions and solar energy utilization. However, the rarity and high cost of noble metals limit their applications in plasmonic photocatalysis, forcing researchers to seek low-cost alternatives. Recently, some heavily doped semiconductors with high free carrier density have garnered attention due to their metal-like LSPR properties.

Constructing High-Active Surface of Plasmonic Tungsten Oxide for Photocatalytic Alcohol Dehydration.

Plasmonic semiconductors with broad spectral response hold significant promise for sustainable solar energy utilization. However, the surface inertness limits the photocatalytic activity. Herein, a novel approach is proposed to improve the body crystallinity and increase the surface oxygen vacancies of plasmonic tungsten oxide by the combination of hydrochloric acid (HCl) regulation and light irradiation, which can promote the adsorption of tert-butyl alcohol (TBA) on plasmonic tungsten oxide and overcome the hindrance of the surface depletion layer in photocatalytic alcohol dehydration.

Non-metallic plasmon-assisted upconversion fluorescence for ultrasensitive hydrogen peroxide detection from nM to μM.

Precise monitoring and quantification of HO is highly urgent and of great significance for biomedicine, food safety, environmental monitoring, . Herein, we proposed a facile near-infrared (NIR) excited fluorescent probe composed of upconversion nanoparticles (UCNPs) and non-metallic plasmonic WO for ultrasensitive quantitative HO detection. Plasmonic WO with oxygen vacancy-induced LSPR achieved over 680-fold enhancement of upconversion fluorescence at 520 nm, and also acts as the sensitive recognition site for HO.

Composite of formamidinium lead bromide perovskite FAPbBr with reduced graphene oxide (rGO) for efficient H evolution from HBr splitting.

Solar hydrobromic acid (HBr) splitting using perovskite photocatalysts provides an attractive avenue to store solar energy into hydrogen (H) and bromine (Br), while an efficient photocatalytic system is still demanded. As for the semiconductor photocatalyst, formamidinium perovskites show some superiorities in structural stability, light adsorption and charge dynamics compared to their methylammonium counterparts, which are fitter for the photocatalysis process. Herein, the composite of formamidinium lead bromide perovskite (FAPbBr) with reduced graphene oxide (rGO) is prepared using a facile photoreduction method.

Achieving Long-Lived Charge Separated State through Ultrafast Interfacial Hole Transfer in Redox Sites-Isolated CdS Nanorods for Enhanced Photocatalysis.

As opposed to natural photosynthesis, a significant challenge in a semiconductor-based photocatalyst is the limited hole extraction efficiency, which adversely affects solar-to-fuel efficiency. Recent studies have demonstrated that photocatalysts featuring spatially isolated dual catalytic oxidation/reduction sites can yield enhanced hole extraction efficiencies. However, the decay dynamics of excited states in such photocatalysts have not been explored.

On-chip ultrasensitive and rapid hydrogen sensing based on plasmon-induced hot electron-molecule interaction.

Hydrogen energy is a zero-carbon replacement for fossil fuels. However, hydrogen is highly flammable and explosive hence timely sensitive leak detection is crucial. Existing optical sensing techniques rely on complex instruments, while electrical sensing techniques usually operate at high temperatures and biasing condition.

Engineering a Copper Single-Atom Electron Bridge to Achieve Efficient Photocatalytic CO Conversion.

Developing highly efficient and stable photocatalysts for the CO reduction reaction (CO RR) remains a great challenge. We designed a Z-Scheme photocatalyst with N-Cu -S single-atom electron bridge (denoted as Cu-SAEB), which was used to mediate the CO RR. The production of CO and O over Cu-SAEB is as high as 236.

Full-spectrum nonmetallic plasmonic carriers for efficient isopropanol dehydration.

Plasmonic hot carriers have the advantage of focusing, amplifying, and manipulating optical signals via electron oscillations which offers a feasible pathway to influence catalytic reactions. However, the contribution of nonmetallic hot carriers and thermal effects on the overall reactions are still unclear, and developing methods to enhance the efficiency of the catalysis is critical. Herein, we proposed a new strategy for flexibly modulating the hot electrons using a nonmetallic plasmonic heterostructure (named WO-nanowires/reduced-graphene-oxides) for isopropanol dehydration where the reaction rate was 180-fold greater than the corresponding thermocatalytic pathway.

Assembly of gold nanorods functionalized by zirconium-based metal-organic frameworks for surface enhanced Raman scattering.

Surface-enhanced Raman scattering (SERS) is a promising detection technique providing outstanding molecular fingerprint identification and high sensitivity of analytes. Developing sensitive and stable SERS substrates is highly desirable but remains a challenge. We herein report a wet-chemistry approach for the preparation of (Au nanorod core)@(Zr-based metal-organic framework shell) (Au nanorod@Zr-MOF) nanostructures with the Zr-MOF shell thickness ranging from 3 nm to 90 nm.

Light-induced thermal convection for collection and removal of carbon nanotubes.

Carbon nanotubes (CNTs) have exhibited immense potential for applications in biology and medicine, and once their intended purpose is fulfilled, the elimination of residual CNTs is essential to avoid negative effects. In this study, we demonstrated the effective collection and simple removal of CNTs dispersed in a suspension via thermal convection. First, a tapered fiber tip with a cone angle and end diameter of 10° and 3 μm, respectively, was fabricated via a heating and pulling method.

Molecularly imprinted photoelectrochemical sensor for detecting tetrabromobisphenol A in indoor dust and water.

The gradual emissions of tetrabromobisphenol A (TBBPA) from the primitive recycling of E-waste create human health threats, which urgently require to develop an efficient, rapid yet simple detection method. The present study conducts a highly sensitive molecularly imprinted photoelectrochemical sensor (MIPES) containing molecularly imprinted (MI)-TiO, Au, and reduced graphene oxide for the trace detection of TBBPA in indoor dust and surface water from an E-waste recycling area. The photocurrent response is used to evaluate the sensing performance of the MIPES toward TBBPA detection.

Light-Induced In Situ Formation of a Nonmetallic Plasmonic MoS/MoO Heterostructure with Efficient Charge Transfer for CO Reduction and SERS Detection.

Low-cost and abundant reserved nonmetallic plasmonic materials have been regarded as a promising substitute of noble metals for photocatalysis and surface-enhanced Raman scattering (SERS). In this paper, a MoS/MoO heterostructure was synthesized by light-induced in situ partial oxidation of MoS nanosheets, exhibiting strong surface plasmon resonance (SPR) in a vis-near-infrared (NIR) region. Continuously plasmon-induced hot electrons boost CO reduction to CO due to efficient photoelectron injection from MoS to MoO.

Constructing Surface Plasmon Resonance on BiWO to Boost High-Selective CO Reduction for Methane.

Plasmonic BiWO with strong localized surface plasmon resonance (LSPR) around the 500-1400 region is successfully constructed by electron doping. Oxygen vacancies on W-O-W (V1) and Bi-O-Bi (V2) sites are precisely controlled to obtain BiWO-V with LSPR and BiWO-V with defect absorption. Density functional theory (DFT) calculation demonstrates that the V1-induced energy state facilitates photoelectron collection for a long lifetime, resulting in LSPR of BiWO.

Enhancement of exciton emission in WS based on the Kerker effect from the mode engineering of individual Si nanostripes.

Coupling between nanostructures and excitons has attracted great attention for potential applications in quantum information technology. Compared with plasmonic platforms, all-dielectric nanostructures with Mie resonances are more practical because of low-loss, low-cost and CMOS compatibility. However, weak field enhancements in single element dielectric nanostructures hinder their applications in both strong and weak coupling regimes.

Plasmonic hot electron transfer in anisotropic Pt-Au nanodisks boosts electrochemical reactions in the visible-NIR region.

Anisotropic plasmonic metals have attracted significant attention in enhancing the catalytic performance of catalysts due to their broad light-harnessing capabilities and active hot electrons; however, limited investigations have been dedicated towards improving their electrochemical reaction performance in the visible and near infrared (NIR) regions. Herein, anisotropic Pt-edged Au nanodisks (NDs) were synthesized by controlling the preferential loading of Pt and used as catalysts for plasmon-enhanced electrochemical methanol oxidation reactions (MORs) under visible-NIR light irradiation by, and the light-enhanced electric current over the Pt-edged Au NDs was found to be 3-fold higher than that under dark conditions. Wavelength-dependent electric current over the Pt-edged Au NDs for the MOR in the visible-NIR light region demonstrates that the light-induced enhancement of the electric current is due to surface plasmon resonance (SPR) of the Au NDs.

Single-molecule and -particle probing crystal edge/corner as highly efficient photocatalytic sites on a single TiO particle.

The exposed active sites of semiconductor catalysts are essential to the photocatalytic energy conversion efficiency. However, it is difficult to directly observe such active sites and understand the photogenerated electron/hole pairs' dynamics on a single catalyst particle. Here, we applied a quasi-total internal reflection fluorescence microscopy and laser-scanning confocal microscopy to identify the photocatalytic active sites at a single-molecule level and visualized the photogenerated hole-electron pair dynamics on a single TiO particle, the most widely used photocatalyst.

Self-Z-scheme plasmonic tungsten oxide nanowires for boosting ethanol dehydrogenation under UV-visible light irradiation.

Nonstoichiometric tungsten oxides (WO) with abundant oxygen vacancies were synthesized and used as nonmetallic plasmonic photocatalysts to promote ethanol dehydrogenation under UV-visible light irradiation. Plasmonic WO have unique electronic structures that act as Z-scheme heterostructures. UV-excited photoelectrons were injected into the conduction band of WO, stabilizing the free electron density and boosting plasmonic hot electron generation for ethanol dehydrogenation.

Two-Dimensional Au-Nanoprism/Reduced Graphene Oxide/Pt-Nanoframe as Plasmonic Photocatalysts with Multiplasmon Modes Boosting Hot Electron Transfer for Hydrogen Generation.

Two-dimensional Au-nanoprism/reduced graphene oxide (rGO)/Pt-nanoframe was synthesized as plasmonic photocatalyt, exhibiting activity of photocatalytic hydrogen generation greater than those of Au-nanorod/rGO/Pt-nanoframe and metallic plasmonic photocatalyst Pt-Au. The single-particle plasmonic photoluminescence study demonstrated that Au-nanorod has only a longitudinal plasmon resonance mode for hot electron transfer to rGO, while Au-nanoprism has in-plane dipole and multipole surface plasmon resonance modes for hot electron transfer, leading to highly efficient charge separation for hydrogen generation.

In Situ Observation of Single Au Triangular Nanoprism Etching to Various Shapes for Plasmonic Photocatalytic Hydrogen Generation.

In situ etching of single Au triangular nanoprism (TNP) was successfully monitored by the plasmonic photoluminescence (PL) spectra using single-particle microscopy, which provides clear results to understand the geometric and anisotropic dependence of surface plasmon resonance in Au nanostructures. Various Au nanostructures (TNP, obtuse TNP (O-TNP) and nanodisk) were obtained to synthesize anisotropic Pt-Au as plasmonic photocatalyts for hydrogen generation. Single-particle PL spectra and finite-difference time-domain simulations demonstrate that the Pt-edged Au O-TNP has larger tip area and higher plasmon enhanced electrical field for hot electron transfer and charge separation, leading to more efficient photocatalytic hydrogen generation.

Facet-Dependent Photoreduction on Single ZnO Crystals.

Photocatalytic reactions occur at the crystal-solution interface, and hence specific crystal facet expression and surface defects can play an important role. Here we investigate the structure-related photoreduction at zinc oxide (ZnO) microparticles via integrated light and electron microscopy in combination with silver metal photodeposition. This enables a direct visualization of the photoreduction activity at specific crystallographic features.

3D-Array of Au-TiO Yolk-Shell as Plasmonic Photocatalyst Boosting Multi-Scattering with Enhanced Hydrogen Evolution.

Nowadays, how to convert solar energy efficiently to other energies, such as chemical energy, is an important subject. In the present work, gold nanosphere (AuNS) monoencapsulated in TiO hollow nanosphere (Au-TiO) and three-dimensional assembled array of Au-TiO (3D-array) were fabricated to carefully explore the multiscattering effect on the photocatalytic activity of H generation under simulated solar light and visible light irradiation, respectively. Au-TiO with the inner cavity diameter of 176 nm was uniformly synthesized via SiO protection method and then was used as building blocks for construction of 3D-array.

Pt-Au Triangular Nanoprisms with Strong Dipole Plasmon Resonance for Hydrogen Generation Studied by Single-Particle Spectroscopy.

Three anisotropic Pt-covered, Pt-edged, and Pt-tipped Au triangular nanoprisms (TNPs) were prepared by controlling the overgrowth of Pt as photocatalysts for H2 generation. With strong electric field and more interface for the hot electrons transfer, the H2 generation rate of Pt-edged Au TNPs was 3 and 5 times higher than those of Pt-tipped and Pt-covered Au TNPs. Single-particle photoluminescence (PL) spectra and finite-difference-time-domain (FDTD) simulations demonstrated that dipole surface plasmon resonance (DSPR) of Au TNPs enhanced the hot electrons transfer from Au to Pt leading to H2 generation.

One-step synthesis of amorphous silver silicates with tunable light absorption spectra and photocatalytic activities in the visible region.

A series of amorphous silver silicates with different compositions were synthesized for the first time by one-step co-precipitation. Silicate ions were found to have important role on determining visible light absorption and photocatalytic activities of amorphous silver silicates, and the sample with Ag/Si ratio of 3.20 exhibits optimal photocatalytic activity.