Porous InO Hollow Tube Infused with g-CN for CO Photocatalytic Reduction.

Converting CO into energy-rich fuels by using solar energy is a sustainable solution that promotes a carbon-neutral economy and mitigates our reliance on fossil fuels. However, affordable and efficient CO conversion remains an ongoing challenge. Here, we introduce polymeric g-CN into the pores of a hollow InO microtube.

Shape tunability of copper nanocrystals deposited on nanorods.

The significant role of metal particle geometry in dictating catalytic activity, selectivity, and stability is well established in heterocatalysis. However, this topic is rarely explored in semiconductor-metal hybrid photocatalytic systems, primarily due to the lack of synthetic control over this feature. Herein, we present a new synthetic route for the deposition of metallic Cu nanoparticles with spherical, elliptic, or cubic geometrical shapes, which are selectively grown on one side of the well-established CdSe@CdS nanorod photocatalytic system.

Lateral charge migration in 1D semiconductor-metal hybrid photocatalytic systems.

Colloidal nanorods based on CdS or CdSe, functionalized with metal particles, have proven to be efficient catalysts for light-driven hydrogen evolution. Seeded CdSe@CdS nanorods have shown increasing performance with increasing rod length. This observation was rationalized by the increasing lifetime of the separated charges, as a large distance between holes localized in the CdSe seed and electrons localized at the metal tip decreases their recombination rate.

Nano Schottky?

The existence of a reduced Schottky barrier at the nanoscale junction between semiconductor and metal domains has yet to be acknowledged among the photocatalysis community, despite its critical role in dictating the quality and functionality of the hybrid photocatalytic system.

The Other Dimension-Tuning Hole Extraction via Nanorod Width.

Solar-to-hydrogen generation is a promising approach to generate clean and renewable fuel. Nanohybrid structures such as CdSe@CdS-Pt nanorods were found favorable for this task (attaining 100% photon-to-hydrogen production efficiency); yet the rods cannot support overall water splitting. The key limitation seems to be the rate of hole extraction from the semiconductor, jeopardizing both activity and stability.

Molecular Metallocorrole-Nanorod Photocatalytic System for Sustainable Hydrogen Production.

Invited for this month's cover is the group of Lilac Amirav at Technion-Israel Institute of Technology. The image shows the sustainable solar-driven photocatalytic generation of hydrogen from water using a molecular metallocorrole-nanorod photocatalytic system. The Research Article itself is available at 10.

CO Activation and Hydrogenation on Cu-ZnO/AlO Nanorod Catalysts: An In Situ FTIR Study.

CuZnO/AlO is the industrial catalyst used for methanol synthesis from syngas (CO + H) and is also promising for the hydrogenation of CO to methanol. In this work, we synthesized AlO nanorods (n-AlO) and impregnated them with the CuZnO component. The catalysts were evaluated for the hydrogenation of CO to methanol in a fixed-bed reactor.

Molecular Metallocorrole-Nanorod Photocatalytic System for Sustainable Hydrogen Production.

Solar-driven photocatalytic generation of hydrogen from water is a potential source of clean and renewable fuel. Yet systems that are sufficiently stable and efficient for practical use have not been realized. Here, nanorod photocatalysts that have proven record activity for the water reduction half reaction were successfully combined with molecular metallocorroles suitable for catalyzing the accompanying oxidation reactions.

Gold@Carbon Nitride Yolk and Core-Shell Nanohybrids.

Graphitic carbon nitride (g-CN) is a promising conjugated polymer with visible light responsiveness and numerous intriguing characteristics that make it highly beneficial for a myriad of potential applications. A novel design and universal approach for the fabrication of unique plasmonic g-CN nanoscale hybrids, with well-controlled morphology, is presented. A single gold nanoprism is encapsulated within dense or hollow g-CN spheres for the formation of Au@g-CN core-shell and Au@g-CN yolk-shell nanohybrids.

Photoinduced Self-Assembly of Carbon Nitride Quantum Dots.

The study of nanocrystal self-assembly into superlattices or superstructures is of great significance in nanoscience. Carbon nitride quantum dots (CNQDs), being a promising new group of nanomaterials, however, have hardly been explored in their self-organizing behavior. Here we report of a unique irradiation-triggered self-assembly and recrystallization phenomenon of crystalline CNQDs (c-CNQDs) terminated by abundant oxygen-containing groups.

Towards Solar Factories: Prospects of Solar-to-Chemical Energy Conversion using Colloidal Semiconductor Photosynthetic Systems.

Solar-to-chemical (STC) energy conversion is the fundamental process that nurtures Earth's ecosystem, fixing the inexhaustible solar resource into chemical bonds. Photochemical synthesis endows plants with the primary substances for their development; likewise, an artificial mimic of natural systems has long sought to support human civilization in a sustainable way. Intensive efforts have demonstrated light-triggered production of different solar fuels, such as H , CO, CH and NH , while research on oxidative half-reactions has built up from O generation to organic synthesis, waste degradation and photo-reforming.

Multi-Modal Nano Particle Labeling of Neurons.

The development of imaging methodologies for single cell measurements over extended timescales of up to weeks, in the intact animal, will depend on signal strength, stability, validity and specificity of labeling. Whereas light-microscopy can achieve these with genetically-encoded probes or dyes, this modality does not allow mesoscale imaging of entire intact tissues. Non-invasive imaging techniques, such as magnetic resonance imaging (MRI), outperform light microscopy in field of view and depth of imaging, but do not offer cellular resolution and specificity, suffer from low signal-to-noise ratio and, in some instances, low temporal resolution.

Plasmon-Enhanced Multicarrier Photocatalysis.

Conversion of solar energy into liquid fuel often relies on multielectron redox processes that include highly reactive intermediates, with back reaction routes that hinder the overall efficiency of the process. Here, we reveal that these undesirable reaction pathways can be minimized, rendering the photocatalytic reactions more efficient, when charge carriers are harvested from a multiexcitonic state of a semiconductor photocatalyst. A plasmonic antenna, comprising Au nanoprisms, was employed to accomplish feasible levels of multiple carrier excitations in semiconductor nanocrystal-based photocatalytic systems (CdSe@CdS core-shell quantum dots and CdSe@CdS seeded nanorods).

Size Matters: Cocatalyst Size Effect on Charge Transfer and Photocatalytic Activity.

Hybrid semiconductor-metallic nanostructures play an important role in a wide range of applications and are key components in photocatalysis. Here we reveal that the nature of a nanojunction formed between a semiconductor nanorod and metal nanoparticle is sensitive to the size of the metal component. This is reflected in the activity toward hydrogen production, emission quantum yields, and the efficiency of charge separation which is determined by transient absorption spectroscopy.

Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods.

We demonstrate a procedure for the photochemical oxidative growth of iridium oxide catalysts on the surface of seeded cadmium selenide-cadmium sulfide (CdSe@CdS) nanorod photocatalysts. Seeded rods are grown using a colloidal hot-injection method and then moved to an aqueous medium by ligand exchange. CdSe@CdS nanorods, an iridium precursor and other salts are mixed and illuminated.

Perfect Photon-to-Hydrogen Conversion Efficiency.

We report a record 100% photon-to-hydrogen production efficiency, under visible light illumination, for the photocatalytic water-splitting reduction half-reaction. This result was accomplished by utilization of nanoparticle-based photocatalysts, composed of Pt-tipped CdSe@CdS rods, with a hydroxyl anion-radical redox couple operating as a shuttle to relay the holes. The implications of such record efficiency for the prospects of realizing practical over all water splitting and solar-to-fuel energy conversion are discussed.

Designing Bimetallic Co-Catalysts: A Party of Two.

The enhanced catalytic properties of bimetallic particles has made them the focus of extensive research. We compare the photocatalytic activity for hydrogen production of core-shell structures of Au@Pd and Au@(Au/Pd alloy) on seeded rods of CdSe@CdS and show that Au@alloy was superior toward hydrogen production. Our finding reveals that the promotion effects of Au in Pd originate both from the alteration of the electronic structure by the Au core as well as by the atomic rearrangement of the surface.

Less Is More: The Case of Metal Cocatalysts.

We provide evidence that for a multielectron reaction such as hydrogen reduction, the photocatalyst design should include only a single cocatalytic site per each segment of the semiconductor capable of light excitation. This is to ensure that intermediates are formed at close proximity. These findings are demonstrated by evaluating the efficiency for hydrogen production over a nanoparticle-based photocatalyst consisting of Pt-decorated CdSe@CdS rods.

Modular synthesis of a dual metal-dual semiconductor nano-heterostructure.

Reported is the design and modular synthesis of a dual metal-dual semiconductor heterostructure with control over the dimensions and placement of its individual components. Analogous to molecular synthesis, colloidal synthesis is now evolving into a series of sequential synthetic procedures with separately optimized steps. We detail the challenges and parameters that must be considered when assembling such a multicomponent nanoparticle, and their solutions.

A spray-based technique for the production of MnS thin films.

A spray-based technique, originally developed for the production of semiconductor nanocrystals, is utilized for the preparation of high-quality nanocrystalline thin films, as demonstrated with manganese sulfide. The films are formed by the use of pneumatic-assisted thermospray or pneumatic nebulizers. Our simple, low-cost, and low-temperature process results in a dense and phase-pure grain structure.

Luminescence studies of individual quantum dot photocatalysts.

Using far-field optical microscopy we report the first measurements of photoluminescence from single nanoparticle photocatalysts. Fluence-dependent luminescence is investigated from metal-semiconductor heterojunction quantum dot catalysts exposed to a variety of environments, ranging from gaseous argon to liquid water containing a selection of hole scavengers. The catalysts each exhibit characteristic nonlinear fluence dependence.

Nanoheterostructure cation exchange: anionic framework conservation.

In ionic nanocrystals the cationic sublattice can be replaced with a different metal ion via a fast, simple, and reversible place exchange, allowing postsynthetic modification of the composition of the nanocrystal, while preserving its size and shape. Here, we demonstrate that, during such an exchange, the anionic framework of the crystal is preserved. When applied to nanoheterostructures, this phenomenon ensures that compositional interfaces within the heterostructure are conserved throughout the transformation.

Spray-produced coral-shaped assemblies of MnS nanocrystal clusters.

A novel spray-based technique enables the production of high-quality, free, uncoated semiconductor nanocrystals. Their collection, following spray droplet desolvation during flight, could result in unusual structures. We report on spray-produced ordered clusters (approximately 50 nm diameter) of MnS nanocrystals with grain size range of 1-2 nm and their assembly into micron-sized coral-shaped fractal aggregates.

Electrostatic and covalent interactions in CdTe nanocrystalline assemblies.

This paper focuses on the interactions between cysteamine-stabilized CdTe nanocrystals [CdTe(CA) NCs] and thioglycolic-acid-stabilized CdTe nanocrystals [CdTe(TGA) NCs]. These interactions were examined by the absorption, continuous, and time-resolved photoluminescence (PL) spectra of the electrostatically mixed and the covalently linked NCs assemblies comprised of the oppositely surface charged CdTe(CA) and CdTe(TGA) NCs and by a comparison with those of the corresponding pristine NCs. The CdTe(CA)-CdTe(TGA) coupling is dictated by the surfactant spacer, ranging between 0.