Covalent Graphene-Metal-Organic Polyhedra Hybrids: Triboelectric Nanogenerators for Next Generation of Wearable E-Skin Technologies.

The development of stretchable energy-harvesting devices that convert mechanical stimuli into electrical energy is crucial for advancing self-powered electronic skin (e-skin) technologies. Triboelectric nanogenerators (TENGs) show promise but suffer from low stretchability, limited conductivity, and poor mechanical durability. Here, we report a new generation of TENGs designed via the molecular chemistry of metal-organic polyhedra (MOPs) covalently bonded to functionalized 2D nitrogen-doped graphene sheets (NG@MOP).

Spaced Hybrid TiO/Au Nanotube Arrays with Tailored Optical Properties for Surface-Enhanced Raman Scattering.

Controlling the overall geometry of plasmonic materials allows for tailoring their optical response and the effects that can be exploited to enhance the performance of a wide range of devices. This study demonstrates a simple method to control the size and distribution of gold (Au) nanoparticles grown on the surface of spaced titanium dioxide (TiO) nanotubes by varying the deposition time of magnetron sputtering. While shorter depositions led to small and well-separated Au nanoparticles, longer depositions promoted the formation of quasi-continuous layers with small interparticle gaps.

Mass Transport Limitations in Plasmonic Photocatalysis.

The interpretation of mechanisms governing hot carrier reactivity on metallic nanostructures is critical, yet elusive, for advancing plasmonic photocatalysis. In this work, we explored the influence of the diffusion of molecules on the hot carrier extraction rate at the solid-liquid interface, which is of fundamental interest for increasing the efficiency of photodevices. Through a spatially defined scanning photoelectrochemical microscopy investigation, we identified a diffusion-controlled regime hindering the plasmon-driven photochemical activity of metallic nanostructures.

Charge carrier recombination processes, intragap defect states, and photoluminescence mechanisms in stoichiometric and reduced TiO brookite nanorods: an interpretation scheme through photoluminescence excitation spectroscopy in controlled environment.

The study of titanium dioxide (TiO) in the brookite phase is gaining popularity as evidence has shown the efficient photocatalytic performance of this less investigated polymorph. It has been recently reported that defective anisotropic brookite TiO nanorods display remarkable substrate-specific reactivity towards alcohol photoreforming, with rates of hydrogen production significantly (18-fold) higher than those exhibited by anatase TiO nanoparticles. To elucidate the basic photo-physical mechanisms and peculiarities leading to such an improvement in the photoactive efficiency, we investigated the recombination processes of photoexcited charge carriers in both stoichiometric and reduced brookite nanorods photoluminescence excitation spectroscopy in controlled environment.

Correction: α-FeO/TiO 3D hierarchical nanostructures for enhanced photoelectrochemical water splitting.

Correction for 'α-FeO/TiO 3D hierarchical nanostructures for enhanced photoelectrochemical water splitting' by Hyungkyu Han , , 2017, , 134-142, https://doi.org/10.1039/C6NR06908H.

Correction to "Band Gap and Morphology Engineering of Hematite Nanoflakes from an Sn Doping for Enhanced Photoelectrochemical Water Splitting".

[This corrects the article DOI: 10.1021/acsomega.2c04028.

Nanoporous Titanium Oxynitride Nanotube Metamaterials with Deep Subwavelength Heat Dissipation for Perfect Solar Absorption.

We report a quasi-unitary broadband absorption over the ultraviolet-visible-near-infrared range in spaced high aspect ratio, nanoporous titanium oxynitride nanotubes, an ideal platform for several photothermal applications. We explain such an efficient light-heat conversion in terms of localized field distribution and heat dissipation within the nanopores, whose sparsity can be controlled during fabrication. The extremely large heat dissipation could not be explained in terms of effective medium theories, which are typically used to describe small geometrical features associated with relatively large optical structures.

Plasmonic titanium nitride nanomaterials prepared by physical vapor deposition methods.

Titanium nitride (TiN) has recently emerged as an alternative to coinage metals to enable the development of integrated plasmonic devices at visible and medium-infrared wavelengths. In this regard, its optical performance can be conveniently tuned by tailoring the process parameters of physical vapor deposition methods, such as magnetron sputtering and pulsed laser deposition (PLD). This review first introduces the fundamental features of TiN and a description on its optical properties, including insights on the main experimental techniques to measure them.

Interfacial States in Au/Reduced TiO Plasmonic Photocatalysts Quench Hot-Carrier Photoactivity.

Understanding the interface of plasmonic nanostructures is essential for improving the performance of photocatalysts. Surface defects in semiconductors modify the dynamics of charge carriers, which are not well understood yet. Here, we take advantage of scanning photoelectrochemical microscopy (SPECM) as a fast and effective tool for detecting the impact of surface defects on the photoactivity of plasmonic hybrid nanostructures.

Thermoplasmonic In Situ Fabrication of Nanohybrid Electrocatalysts over Gas Diffusion Electrodes for Enhanced HO Electrosynthesis.

Large-scale development of electrochemical cells is currently hindered by the lack of Earth-abundant electrocatalysts with high catalytic activity, product selectivity, and interfacial mass transfer. Herein, we developed an electrocatalyst fabrication approach which responds to these requirements by irradiating plasmonic titanium nitride (TiN) nanocubes self-assembled on a carbon gas diffusion layer in the presence of polymeric binders. The localized heating produced upon illumination creates unique conditions for the formation of TiN/F-doped carbon hybrids that show up to nearly 20 times the activity of the pristine electrodes.

Ultrasound-Driven Defect Engineering in TiO Nanotubes─Toward Highly Efficient Platinum Single Atom-Enhanced Photocatalytic Water Splitting.

Single-atom catalysts (SACs) have demonstrated superior catalytic activity and selectivity compared to nanoparticle catalysts due to their high reactivity and atom efficiency. However, stabilizing SACs within hosting substrates and their controllable loading preventing single atom clustering remain the key challenges in this field. Moreover, the direct comparison of (co-) catalytic effect of single atoms vs nanoparticles is still highly challenging.

Fluoranthene-terminated terpyridine ensemble for fluorescence light up and ratiometric chemical sensor for multi toxic metals.

A novel π-electron rich fluoranthene embellished with a phenyl spacer and coupled with terpyridine (TS1) was developed through Diels-Alder reaction. Single crystal X-ray structure evidences the variations in dihedral angles between the fluoranthene and the phenyl unit responsible for development of non-coplanar interactions and stabilized by a wave-like molecular packing in the crystal lattice with weak π-π interaction of 4.125 Å.

Magnetic Polaron States in Photoluminescent Carbon Dots Enable Hydrogen Peroxide Photoproduction.

Photoactivation of aspartic acid-based carbon dots (Asp-CDs) induces the generation of spin-separated species, including electron/hole (e /h ) polarons and spin-coupled triplet states, as uniquely confirmed by the light-induced electron paramagnetic resonance spectroscopy. The relative population of the e /h pairs and triplet species depends on the solvent polarity, featuring a substantial stabilization of the triplet state in a non-polar environment (benzene). The electronic properties of the photoexcited Asp-CDs emerge from their spatial organization being interpreted as multi-layer assemblies containing a hydrophobic carbonaceous core and a hydrophilic oxygen and nitrogen functionalized surface.

Graphene-Based Metal-Organic Framework Hybrids for Applications in Catalysis, Environmental, and Energy Technologies.

Current energy and environmental challenges demand the development and design of multifunctional porous materials with tunable properties for catalysis, water purification, and energy conversion and storage. Because of their amenability to de novo reticular chemistry, metal-organic frameworks (MOFs) have become key materials in this area. However, their usefulness is often limited by low chemical stability, conductivity and inappropriate pore sizes.

Band gap and Morphology Engineering of Hematite Nanoflakes from an Sn Doping for Enhanced Photoelectrochemical Water Splitting.

In this article, we report a simple Sn-doping method on hematite nanoflakes (coded as MSnO-H) that can protect the nanoflake (NF) morphology against the 800 °C high-temperature annealing process and activate the photoresponse of hematite until 800 nm wavelength excitation. MSnO-H has been fabricated by dropping SnCl ethanol solution on hematite nanoflakes homogeneously grown over the conductive FTO glass substrate and annealed at 500 °C to synthesize the SnO nanoparticles on hematite NFs. The Sn-treated samples were then placed in a furnace again, and the sintering process was conducted at 800 °C for 15 min.

Determining the role of Pd catalyst morphology and deposition criteria over large area plasmonic metasurfaces during light-enhanced electrochemical oxidation of formic acid.

The use of metal composites based on plasmonic nanostructures partnered with catalytic counterparts has recently emerged as a promising approach in the field of plasmon-enhanced electrocatalysis. Here, we report on the role of the surface morphology, size, and anchored site of Pd catalysts coupled to plasmonic metasurfaces formed by periodic arrays of multimetallic Ni/Au nanopillars for formic acid electro-oxidation reaction (FAOR). We compare the activity of two kinds of metasurfaces differing in the positioning of the catalytic Pd nanoparticles.

Rational Design of Graphene Derivatives for Electrochemical Reduction of Nitrogen to Ammonia.

The conversion of nitrogen to ammonia offers a sustainable and environmentally friendly approach for producing precursors for fertilizers and efficient energy carriers. Owing to the large energy density and significant gravimetric hydrogen content, NH is considered an apt next-generation energy carrier and liquid fuel. However, the low conversion efficiency and slow production of ammonia through the nitrogen reduction reaction (NRR) are currently bottlenecks, making it an unviable alternative to the traditional Haber-Bosch process for ammonia production.

Optimized Pt Single Atom Harvesting on TiO Nanotubes-Towards a Most Efficient Photocatalyst.

In the present work the authors show that anodic TiO nanotubes (NT) show excellent harvesting properties for Pt single atoms (Pt SAs) from highly dilute Pt solutions. The tube walls of anodic nanotubes, after adequate annealing to anatase, provide ample of suitable trapping sites-that is, surface Ti -O (O : oxygen vacancy) defects that are highly effective to extract and accumulate Pt in the form of SAs. A saturated (maximized) SA density can be achieved by an overnight immersion of a TiO NT layer to a H PtCl solution with a concentration that is as low as 0.

Uncovering the Role of Trioctylphosphine on Colloidal and Emission Stability of Sb-Alloyed CsNaInCl Double Perovskite Nanocrystals.

Doping and compositional tuning of CsAInCl (A = Ag, Na) double perovskite nanocrystals (PNCs) is considered a promising strategy toward the development of light-emitting sources for applications in solution-processed optoelectronic devices. Oleic acid and oleylamine are by far the most often used surface capping ligands for PNCs. However, the undesirable desorption of these ligands due to proton-exchange reaction during isolation and purification processing results in colloidal and structural instabilities.

As a single atom Pd outperforms Pt as the most active co-catalyst for photocatalytic H evolution.

Here, we evaluate three different noble metal co-catalysts (Pd, Pt, and Au) that are present as single atoms (SAs) on the classic benchmark photocatalyst, TiO. To trap the single atoms on the surface, we introduced controlled surface vacancies (Ti-O) on anatase TiO nanosheets by a thermal reduction treatment. After anchoring identical loadings of single atoms of Pd, Pt, and Au, we measure the photocatalytic H generation rate and compare it to the classic nanoparticle co-catalysts on the nanosheets.

Light-Induced Migration of Spin Defects in TiO Nanosystems and their Contribution to the H Evolution Catalysis from Water.

The photocatalytic activity for H production from water, without presence of hole scavengers, of thermally reduced TiO nanoparticles (H-500, H-700) and neat anatase were followed by in-situ continuous-wave light-induced electron paramagnetic resonance technique (CW-LEPR), in order to correlate the H evolution rates with the electronic fingerprints of the photoexcited systems. Under UV irradiation, photoexcited electrons moved from the deep lattice towards the superficially exposed Ti sites. These photogenerated redox sites mediated (e +h ) recombination and were the crucial electronic factor affecting catalysis.

Spatially Confined Formation of Single Atoms in Highly Porous Carbon Nitride Nanoreactors.

Reducing the size of a catalyst to a single atom (SA) level can dramatically change its physicochemical properties and significantly boost its catalytic activity. However, the massive synthesis of SA catalysts still remains a grand challenge mainly because of the aggregation and nucleation of the generated atoms during the reaction. Here, we design and implement a spatially confined synthetic strategy based on a porous-hollow carbon nitride (-CN) coordinated with 1-butyl-3-methylimidazole hexafluorophosphate, which can act as a nanoreactor and allow us to obtain metal SA catalysts (-CN@M SAs).