On Structural Features Necessary for Near‐IR‐Light Photocatalysts

In the search for photocatalysts that can directly utilize near‐IR (NIR) light, we investigated three oxides Cu₃(OH)₄SO₄ (antlerite), Cu₄(OH)₆SO₄, and Cu₂(OH)₃Cl by photodecomposing 2,4‐dichlorophenol over them under NIR irradiation and by comparing their electronic structures with that of the known NIR photocatalyst Cu₂(OH)PO₄. Both Cu₃(OH)₄SO₄ and Cu₄(OH)₆SO₄ are NIR photocatalysts, but Cu₂(OH)₃Cl is not. Thus, in addition to the presence of two different CuO_m and Cu′O_n polyhedra linked with Cu?O?Cu′ bridges, the presence of acceptor groups (e.g., SO₄, PO₄) linked to the metal oxygen polyhedra is necessary for NIR photocatalysts.     

Superior Photostability and Photocatalytic Activity of ZnO Nanoparticles Coated with Ultrathin TiO2 Layers through Atomic‐Layer Deposition

Atomic‐layer deposition (ALD) is a thin‐film growth technology that allows for conformal growth of thin films with atomic‐level control over their thickness. Although ALD is successful in the semiconductor manufacturing industry, its feasibility for nanoparticle coating has been less explored. Herein, the ALD coating of TiO₂ layers on ZnO nanoparticles by employing a specialized rotary reactor is demonstrated. The photocatalytic activity and photostability of ZnO nanoparticles coated with TiO₂ layers by ALD and chemical methods were examined by the photodegradation of Rhodamine B dye under UV irradiation. Even though the photocatalytic activity of the presynthesized ZnO nanoparticles is higher than that of commercial P25 TiO₂ nanoparticles, their activity tends to decline due to severe photocorrosion. The chemically synthesized TiO₂ coating layer on ZnO resulted in severely declined photoactivity despite the improved photostability. However, ultrathin and conformal ALD TiO₂ coatings (≈0.75–1.5 nm) on ZnO improved its photostability without degradation of photocatalytic activity. Surprisingly, the photostability is comparable to that of pure TiO₂, and the photocatalytic activity to that of pure ZnO.     

pH-induced structural changes of surface immobilized poly(L-lysine) by two-dimensional (2D) infrared correlation study

This paper reports the pH-induced structural changes in the surface immobilized poly(L-lysine)(PLL)film.Two-dimensional(2D) correlation analysis was applied to the Fourier transform infrared(FTIR)spectra of the surface-immobilized PLL film to examine the spectral changes induced by the alternations of the protonation state of the amino group in the side chain.Significant spectral changes in the FTIR spectra of the PLL film were observed between pH 7 and 8.The decrease in the protonation state of the amino group in the side chain induced spectral changes in the amino group as well as conformational changes in the alky]group in the side chain.From pH 1-8,the spectral changes in the amino and alkyl groups in the side chain occurred before those of the amide group in the main chain of the surface immobilized PLL film.     

CuSbS2‐Sensitized Inorganic–Organic Heterojunction Solar Cells Fabricated Using a Metal–Thiourea Complex Solution

The device performance of sensitizer‐architecture solar cells based on a CuSbS₂ light sensitizer is presented. The device consists of F‐doped SnO₂ substrate/TiO₂ blocking layer/mesoporous TiO₂/CuSbS₂/hole‐transporting material/Au electrode. The CuSbS₂ was deposited by repeated cycles of spin coating of a Cu‐Sb‐thiourea complex solution and thermal decomposition, followed by annealing in Ar at 500 °C. Poly(2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)) (PCPDTBT) was used as the hole‐transporting material. The best‐performing cell exhibited a 3.1 % device efficiency, with a short‐circuit current density of 21.5 mA cm^?2, an open‐circuit voltage of 304 mV, and a fill factor of 46.8 %.     

Development of Imidazoline‐2‐Thiones Based Two‐Photon Fluorescence Probes for Imaging Hypochlorite Generation in a Co‐Culture System

We designed and prepared the imidazoline‐2‐thione containing OCl^? probes, PIS and NIS , which operate through specific reactions with OCl^? that yield corresponding fluorescent imidazolium ions. Importantly, we demonstrated that PIS can be employed to image OCl^? generation in macrophages in a co‐culture system. We have also employed two‐photon microscopy and PIS to image OCl^? in live cells and tissues, indicating that this probe could have wide biological applications.     

Organization and Energy Transfer of Fused Aromatic Hydrocarbon Guests within Anion‐Confining Nanochannel MOFs

The self‐assembly of Zn^II ions with 1,3,5‐tris(isonicotinoyloxyethyl)cyanurate produces new topological (4²?12⁴)₃(4³)₄ 2D metal–organic frameworks (MOFs) with anion‐confining cages. The eclipsed assembly of each 2D MOF by π–π stacking of cyanurate moieties (3.352(5) Å) forms 3D MOFs consisting of nanochannels (10.5 Å). Two of the three anions are confined in each peanut‐type cage, resulting in hydrophobicity of the nanochannels. The hydrophobic nanochannel effectively adsorbs a wide range of fused aromatic hydrocarbons (FAHs) as monomers or dimers, rendering it potentially highly useful as an energy‐transfer material.     

Metal Coordination Sphere Deformation Induced Highly Stokes-Shifted,Ultra Broadband Emission in 2D Hybrid Lead-Bromide Perovskites and Investigation of Its Origin

Published studies of layered (2D) (100)-oriented hybrid lead-bromide perovskites evidence a correlation between increased inter-octahedral (Pb-Br-Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent [PbBr₆]⁴⁻ octahedra has yet to be assessed. Herein, we report two new (100)-oriented 2D Pb-Br perovskites, whose structures display unusually high intra-octahedral distortions, whilst retaining minimal inter-octahedral distortions. Using a combination of temperature-dependent, power-dependent and time-resolved photoluminescence spectroscopic measurements, we show that increased intra-octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes-shifted, ultrabroad white light emission at room temperature.     

Highly Mesoporous Metal-Organic Frameworks as Synergistic Multimodal Catalytic Platforms for Divergent Cascade Reactions

Rational engineering and assimilation of diverse chemo- and biocatalytic functionalities in a single nanostructure is highly desired for efficient multistep chemical reactions but has so far remained elusive. Here, we design and synthesize multimodal catalytic nanoreactors (MCNRs) based on a mesoporous metal-organic framework (MOF). The MCNRs consist of customizable metal nanocrystals and stably anchored enzymes in the mesopores, as well as coordinatively unsaturated cationic metal MOF nodes, all within a single nanoreactor space. The highly intimate and diverse catalytic mesoporous microenvironments and facile accessibility to the active site in the MCNR enables the cooperative and synergistic participation from different chemo- and biocatalytic components. This was shown by one-pot multistep cascade reactions involving a heterogeneous catalytic nitroaldol reaction followed by a [Pd/lipase]-catalyzed chemoenzymatic dynamic kinetic resolution to yield optically pure (>99 % ee) nitroalcohol derivatives in quantitative yields.     

Anchored Mediator Enabling Shuttle-Free Redox Mediation in Lithium-Oxygen Batteries

Redox mediators (RMs) are considered an effective countermeasure to reduce the large polarization in lithium-oxygen batteries. Nevertheless, achieving sufficient enhancement of the cyclability is limited by the trade-offs of freely mobile RMs, which are beneficial for charge transport but also trigger the shuttling phenomenon. Here, we successfully decoupled the charge-carrying redox property of RMs and shuttling phenomenon by anchoring the RMs in polymer form, where physical RM migration was replaced by charge transfer along polymer chains. Using PTMA (poly(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl methacrylate)) as a polymer model system based on the well-known RM tetramethylpiperidinyloxyl (TEMPO), it is demonstrated that PTMA can function as stationary RM, preserving the redox activity of TEMPO. The efficiency of RM-mediated Li₂O₂ decomposition remains remarkably stable without the consumption of oxidized RMs or degradation of the lithium anode, resulting in an improved performance of the lithium-oxygen cell.