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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. However, the impact of nanorod length on the electron-to-tip localization efficiency or pathway remained an open question. Therefore, we investigated the photo-induced electron transfer to the metal in a series of Ni-tipped CdSe@CdS nanorods with varying length. We find that the transfer processes occurring from the region close to the semiconductor–metal interface, the rod region, and the CdSe seed region depend in different ways on the rods' length. The rate of the fastest process from excitonic states generated directly at the interface is independent of the rod length, but the relative amplitude decreases with increasing rod length, as the weight of the interface region is decreasing. The transfer of electrons to the metal tip from excitons generated in the CdS rod region depends strongly on the length of the nanorods, which indicates an electron transport-limited process, i.e., electron diffusion toward the interface region, followed by fast interface crossing. The transfer originating from the CdSe excitonic states again shows no significant length dependence in its time constant, as it is probably limited by the rate of overcoming the shallow confinement in the CdSe seed. [ABSTRACT FROM AUTHOR]

Metal corrosion leads to severe economic losses and safety hazards to human society. As an energy-efficient and sustainable anticorrosion technique, photocathodic protection (PCP) systems have received growing attention in the past two decades. However, the existing PCP devices barely meet the requirements of adequate metal protection in real-world scenarios. This perspective aims to provide some constructive insights into the rational design of PCP devices and propose "functional module integration" as a new concept for future PCP systems. Similarly to multi-layered solar cells, PCP systems may incorporate multiple modules based on the corresponding functions. These include photoabsorber module (PAM), electron transfer module (ETM), hole transfer module (HTM), hole consumption module (HCM), and electron storage module (ESM). With such a modular design, improved capture of sunlight and fast charge separation, directional transportation, and effective utilization of the photogenerated carriers might be attained. Consequently, the solar-to-electric energy conversion efficiency and operation consistency of PCP devices can be significantly boosted, paving the way for practical application of solar-powered metal protection technology. [ABSTRACT FROM AUTHOR]

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. It is suggested that hole extraction might be improved via tuning the rod's dimensions, specifically the width of the CdS shell around the CdSe seed in which the holes reside. In this contribution, we successfully attain atomic-scale control over the width of CdSe@CdS nanorods, which enables us to verify this hypothesis and explore the intricate influence of shell diameter over hole quenching and photocatalytic activity towards H2 production. A non-monotonic effect of the rod's diameter is revealed, and the underlying mechanism for this observation is discussed, alongside implications towards the future design of nanoscale photocatalysts. [ABSTRACT FROM AUTHOR]

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. Utilization of OH−/⋅OH redox species as charge transfer shuttle between freely mixed metallocorroles and rods resulted in quantum efficiency that peaked as high as 17 % for hydrogen production from water in the absence of sacrificial hole scavengers. While typically each sacrificial scavenger is able to extract but a single hole, here the molecular metallocorrole catalysts were found to successfully handle nearly 300,000 holes during their lifespan. The implications of the new system on the prospects of realizing practical overall water splitting and direct solar‐to‐fuel energy conversion were discussed. [ABSTRACT FROM AUTHOR]

Carbon‐heteroatom cross‐coupling reactions are significant for numerous industrial chemical processes, in particular for the synthesis of pharmaceuticals, agrochemicals, and biologically active compounds. Photocatalyst/transition metal dual catalytic systems pave a new avenue for organic cross‐coupling reactions. Specifically, the use of semiconductor nanoparticles as heterogeneous light sensitizers is highly beneficial for industrial‐scale applications owing to their low‐cost production, tunable photophysical properties, facile separation, high photostability, and recyclability. Here, CdSe@CdS nanorod photocatalysts are combined with a Ni complex catalyst for the promotion of selective light‐induced C−O cross‐coupling reactions between aryl halides and alkyl carboxylic acids. This efficient dual photocatalytic system displays a high yield (∼96 %), with an impressive turnover number (TON) of over 3×106, and within a relatively short reaction time as a result of high turnover frequency (TOF) of ∼56 s−1. In addition, the nanorod photocatalysts harness light with improved solar to product efficiency compared to alternative systems, signaling towards potential solar‐powered chemistry. A reaction mechanism involving energy transfer from the nanorods to the Ni complex is proposed and discussed, along with specific benefits of the seeded rod morphology. [ABSTRACT FROM AUTHOR]

CuZnO/Al2O3 is the industrial catalyst used for methanol synthesis from syngas (CO + H2) and is also promising for the hydrogenation of CO2 to methanol. In this work, we synthesized Al2O3 nanorods (n-Al2O3) and impregnated them with the CuZnO component. The catalysts were evaluated for the hydrogenation of CO2 to methanol in a fixed-bed reactor. The support and the catalysts were characterized, including via in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The study of the CO2 adsorption, activation, and hydrogenation using in situ DRIFT spectroscopy revealed the different roles of the catalyst components. CO2 mainly adsorbed on the n-Al2O3 support, forming carbonate species. Cu was found to facilitate H2 dissociation and further reacted with the adsorbed carbonates on the n-Al2O3 support, transforming them to formate or additional intermediates. Like the n-Al2O3 support, the ZnO component contributed to improving the CO2 adsorption, facilitating the formation of more carbonate species on the catalyst surface and enhancing the efficiency of the CO2 activation and hydrogenation into methanol. The synergistic interaction between Cu and ZnO was found to be essential to increase the space–time yield (STY) of methanol but not to improve the selectivity. The 3% CuZnO/n-Al2O3 displayed improved catalytic performance compared to 3% Cu/n-Al2O3, reaching a CO2 conversion rate of 19.8% and methanol STY rate of 1.31 mmolgcat−1h−1 at 300 °C. This study provides fundamental and new insights into the distinctive roles of the different components of commercial methanol synthesis catalysts. [ABSTRACT FROM AUTHOR]

The use of photosystem II (PSII) in hybrid bio-photoelectrochemical cells for conversion of solar energy to electrical current is hampered by PSII's narrow absorption cross-section and the generally poor electrical connection between isolated complex and different anode materials. Here, we merge isolated market-grade spinach PSII with 25 nm cystamine-2,6-dichlorobenzoquinone (cys-DCBQ) modified Au-nanoparticles (PSII–AuNPCys-DCBQ) to obtain one of the highest reported photocurrent values to date (35 mA cm−2 mg−1 chlorophyll), retaining the native oxygen evolution properties of PSII. More than 80% of the PSII in solution assembles stably onto the AuNPCys-DCBQ. Spectroscopic studies show strong functional association in these hybrid particles. Mechanistic investigations reveal a dual role of the quinone-modified AuNPs, harvesting and transference of the excitation energy to PSII (resulting in ∼10-fold enhancement of anodic photocurrent in the 500–550 nm irradiation range) and simultaneously improving the electron transfer from PSII into the graphite anode (by almost 6-fold over the entire visible range of light). [ABSTRACT FROM AUTHOR]

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. Unlike the conventional self‐assembly of nanocrystals into ordered superstructures, the photoinduced self‐assembly of c‐CNQDs resembles a "click reaction" process of macromolecules, in which the activated ‐OH and ‐NH2 functional groups along the perimeters initiate cross‐linking of adjacent QDs through a photocatalytic effect. Our findings unveil fundamental physiochemical features of CNQDs and open up new possibilities of manipulating carbon nitride nanomaterials via controlled assembly. Prospects for potential applications are discussed as well. [ABSTRACT FROM AUTHOR]

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. Unlike the conventional self‐assembly of nanocrystals into ordered superstructures, the photoinduced self‐assembly of c‐CNQDs resembles a "click reaction" process of macromolecules, in which the activated ‐OH and ‐NH2 functional groups along the perimeters initiate cross‐linking of adjacent QDs through a photocatalytic effect. Our findings unveil fundamental physiochemical features of CNQDs and open up new possibilities of manipulating carbon nitride nanomaterials via controlled assembly. Prospects for potential applications are discussed as well. [ABSTRACT FROM AUTHOR]

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 H2, CO, CH4 and NH3, while research on oxidative half‐reactions has built up from O2 generation to organic synthesis, waste degradation and photo‐reforming. Nevertheless, while extensive utilization of the radiant chemical potential to promote a manifold of endergonic processes is the common thread of such research, exploration of the chemical space is fragmented by the lack of a common language across different scientific disciplines. Focusing on colloidal semiconductor materials, this Viewpoint discusses an inclusive protocol for the discovery and assessment of STC redox reactions, aiming to establish photon‐to‐molecule conversion as the ultimate paradigm beyond fossil energy exploitation. [ABSTRACT FROM AUTHOR]

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. In addition, the origins of the signals measured by MRI are either indirect to the process of interest or hard to validate. It is therefore highly warranted to find means to enhance MRI signals to allow increases in resolution and cellular-specificity. To this end, cell-selective bi-functional magneto-fluorescent contrast agents can provide an elegant solution. Fluorescence provides means for identification of labeled cells and particles location after MRI acquisition, and it can be used to facilitate the design of cell-selective labeling of defined targets. Here we briefly review recent available designs of magneto-fluorescent markers and elaborate on key differences between them with respect to durability and relevant cellular highlighting approaches. We further focus on the potential of intracellular labeling and basic functional sensing MRI, with assays that enable imaging cells at microscopic and mesoscopic scales. Finally, we illustrate the qualities and limitations of the available imaging markers and discuss prospects for in vivo neural imaging and large-scale brain mapping. [ABSTRACT FROM AUTHOR]

We demonstrate improved efficiency for the photocatalytic water splitting reduction half reaction by employing Au–Pt bimetallic cocatalysts. We employed nanoparticle-based photocatalysts consisting of CdSe@CdS rods tipped with Au, Pt, Au–Pt core–shell or Au decorated with Pt islands. By tailoring the composition and morphology of the Au–Pt bimetallic catalysts, we achieved more than a fourfold increase in activity for hydrogen production compared to pure Pt. [ABSTRACT FROM AUTHOR]

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. This multicomponent nanosystem, Ru-CdSe@CdS-Pt, was designed to achieve charge carrier separation and directional transfer across different interfaces toward two separate redox catalysts. This heterostructure may potentially serve as a nanometric closed circuit photoelectrochemical cell. [ABSTRACT FROM AUTHOR]

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. This multicomponent nanosystem, Ru-CdSe@CdS-Pt, was designed to achieve charge carrier separation and directional transfer across different interfaces toward two separate redox catalysts. This heterostructure may potentially serve as a nanometric closed circuit photoelectrochemical cell. [ABSTRACT FROM AUTHOR]

The combination of photochemical oxidation with colloidal synthesis enables us to re-think the design of photocatalysts with an eye towards overall water splitting. Here, IrO2 nanoparticle oxidative catalysts that were photodeposited on colloidal CdSe@CdS nanorod photocatalysts revealed a mediated oxidative pathway, and afforded the rods remarkable photochemical stability under prolonged illumination in pure water. [ABSTRACT FROM AUTHOR]

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 10.1002/cssc.202200804. [ABSTRACT FROM AUTHOR]

It is accomplished via a successful combination of nanorod photocatalysts that have proven record activity for the water reduction half-reaction, with molecular metallocorroles suitable for catalyzing the accompanying oxidation reactions. The utilization of redox species as charge transfer shuttle between freely mixed molecular catalysts and rods afford a simple and elegant alternative to a chemical linkage, which results in high quantum efficiency for hydrogen production. Keywords: molecular catalysts; nanorods; photocatalysis; solar hydrogen; water splitting EN molecular catalysts nanorods photocatalysis solar hydrogen water splitting 1 1 1 09/09/22 20220907 NES 220907 B The Front Cover b shows the solar-driven photocatalytic generation of hydrogen from water. [Extracted from the article]