Manipulating Chiroptical Activities in 0D Chiral Hybrid Manganese Bromides by Solvent Molecular Engineering.

0D hybrid metal halides (0D HMHs) with fully isolated inorganic units provide an ideal platform for studying the correlations between chiroptical activities and crystal structures at atomic levels. Here, through the incorporation of different solvent molecules, a series of 0D chiral manganese bromides (RR/SS-C20H28N2)3MnBr8·2X (X = C2H5OH, CH3OH, or H2O) are synthesized to elucidate their chiroptical properties. They show negligible circular dichroism signals of Mn absorptions due to C2v-symmetric [MnBr4]2- tetrahedra. However, they display distinct circularly polarized luminescence (CPL) signals with continuously increased luminescence asymmetry factors (glum) from 10-4 (X = C2H5OH) to 10-3 (X = H2O). The increased glum value is structurally revealed to originate from the enhancement of [MnBr4]2- tetrahedral bond-angle distortions, due to the presence of different solvent molecules. Furthermore, (RR/SS-C20H28N2)MnBr4·H2O enantiomers with larger bond-angle distortions of [MnBr4]2- tetrahedra are synthesized based on hydrobromic acid-induced structural transformation of (RR/SS-C20H28N2)3MnBr8·2H2O enantiomers. Therefore, such (RR/SS-C20H28N2)MnBr4·H2O enantiomers exhibit enhanced CPL signals with |glum| up to 1.23 × 10-2. This work provides unique insight into enhancing chiroptical activities in 0D HMH systems.

Temperature and pressure-induced excitation-dependent emissions in zero-dimensional hybrid metal halides with mixed halogens.

Zero-dimensional (0D) hybrid metal halides (HMHs) have emerged as a promising platform for exploring excitation-dependent multicolor luminescent materials owing to their diverse crystal structures and chemical compositions. Nevertheless, understanding the mechanism behind excitation-dependent emissions (EDEs) in 0D HMHs and achieving precise modulation remains challenging. In this work, the delicate regulations on the EDE of 0D (DMEDABr)4SnBr3I3 (DMEDA: N, N'-dimethylethylenediamine) with mixed halogens are achieved under low temperature and high pressure, respectively. The inhomogeneous halogen occupation at the atomic scale leads to the formation of Br-rich and I-rich SnX6 (X = Br, I) octahedra, which act as distinct luminescent centers upon photoexcitation. At low temperatures, the narrowed photoluminescence spectra could distinguish the individual emissions from different luminescent centers, resulting in a pronounced EDE of (DMEDABr)4SnBr3I3. In addition, the contraction and distortion of the luminescent SnX6 (X = Br, I) centers at high pressure further result in different degrees of emission shifts, giving rise to the gradual emergence and disappearance of EDE. This work elucidates the underlying mechanism of EDE in 0D HMHs and highlights the crucial role of halogens in determining the optical properties of metal halides.

Efficient Ultraviolet Circularly Polarized Luminescence in Zero-Dimensional Hybrid Cerium Bromides.

Ultraviolet circularly polarized luminescence (UV-CPL) with high photon energy shows great potential in polarized light sources and stereoselective photopolymerization. However, developing luminescent materials with high UV-CPL performance remains challenging. Here, we report a pair of rare earth Ce3+-based zero-dimensional (0D) chiral hybrid metal halides (HMHs), R/S-(C14H24N2)2CeBr7, which exhibits characteristic UV emissions derived from the Ce 5d-4f transition. The compounds show simultaneously high photoluminescent quantum yields of (32-39)% and large luminescent dissymmetry factor (|glum|) values of (1.3-1.5)×10-2. Thus, the figures of merits of R/S-(C14H24N2)2CeBr7 are calculated to be (4.5-5.8)×10-3, which are superior to the reported UV-CPL emissive materials. Additionally, nearly 91 % of their PL intensities at 300 K can be well preserved at 380 K (LED operating temperature) without phase transition or decomposition, demonstrating the excellent structural and optical thermal stabilities of R/S-(C14H24N2)2CeBr7. Based on these enantiomers, the fabricated UV-emitting CP-LEDs exhibit high polarization degrees of ±1.0 %. Notably, the UV-CPL generated from the devices can significantly trigger the enantioselective photopolymerization of diacetylene with remarkable stereoselectivity, and consequently yield polymerized products with the anisotropy factors of circular dichroism (gCD) up to ±3.9×10-2, outperforming other UV-CPL materials and demonstrating their great potential as UV-polarized light sources.

Comparative Transcriptomic Analyses Propose the Molecular Regulatory Mechanisms Underlying 1,8-Cineole from Cinnamomum kanehirae Hay and Promote the Asexual Sporulation of Antrodia cinnamomea in Submerged Fermentation.

Antrodia cinnamomea is a valuable edible and medicinal mushroom with antitumor, hepatoprotective, and antiviral effects that play a role in intestinal flora regulation. Spore-inoculation submerged fermentation has become the most efficient and well-known artificial culture process for A. cinnamomea. In this study, a specific low-molecular compound named 1,8-cineole (cineole) from Cinnamomum kanehirae Hay was first reported to have remarkably promoted the asexual sporulation of A. cinnamomea in submerged fermentation (AcSmF). Then, RNA sequencing, real-time quantitative PCR, and a literature review were performed to predict the molecular regulatory mechanisms underlying the cineole-promoted sporulation of AcSmF. The available evidence supports the hypothesis that after receiving the signal of cineole through cell receptors Wsc1 and Mid2, Pkc1 promoted the expression levels of rlm1 and wetA and facilitated their transfer to the cell wall integrity (CWI) signal pathway, and wetA in turn promoted the sporulation of AcSmF. Moreover, cineole changed the membrane functional state of the A. cinnamomea cell and thus activated the heat stress response by the CWI pathway. Then, heat shock protein 90 and its chaperone Cdc37 promoted the expression of stuA and brlA, thus promoting sporulation of AcSmF. In addition, cineole promoted the expression of areA, flbA, and flbD through the transcription factor NCP1 and inhibited the expression of pkaA through the ammonium permease of MEP, finally promoting the sporulation of AcSmF. This study may improve the efficiency of the inoculum (spores) preparation of AcSmF and thereby enhance the production benefits of A. cinnamomea.

Integrating Achiral and Chiral Organic Ligands in Zero-Dimensional Hybrid Metal Halides to Boost Circularly Polarized Luminescence.

Chiral zero-dimensional hybrid metal halides (0D HMHs) could combine excellent optical properties and chirality, making them promising for circularly polarized luminescence (CPL). However, chiral 0D HMHs with efficient CPL have been rarely reported. Here, we propose an efficient strategy to achieve simultaneously high photoluminescence quantum yield (PLQY) and large dissymmetry factor (glum ), by integrating achiral and chiral ligands into 0D HMHs. Specifically, three pairs of chiral 0D hybrid indium-antimony chlorides are synthesized by combing achiral guanidine with three types of chiral methylbenzylammonium-based derivatives as the organic cations. These chiral 0D HMHs exhibit near-unity PLQY and large glum values up to around ±1×10-2 . The achiral guanidine ligand is not only essential to crystallize these hybrid indium-antimony chlorides to achieve near-unity PLQYs, but also greatly enhances the chirality induction from organic ligands to inorganic units in these 0D HMHs. Furthermore, the choice of different chiral ligands can modify the strength of hydrogen bonding interactions in these 0D HMHs, to maximize their glum values. Overall, this study provides a robust way to realize efficient CPL in chiral HMHs, expanding their applications in chiroptical fields.

Organic Cation-Directed Modulation of Emissions in Zero-Dimensional Hybrid Tin Bromides.

Zero-dimensional hybrid metal halides (0D HMHs) are attractive due to their intriguing self-trapped exciton (STE) emission properties. However, the effect of organic cations on the emission of 0D HMHs is relatively underexplored. Herein, we report two types of 0D hybrid tin bromides, (BMe)2SnBr6 (BMe = C8N2H18) and (MeH)2SnBr6 (MeH = C7N2H16), which share similar structural features with different hydrogen bonding (HB) interactions between [SnBr6]4- anions and organic cations. The (BMe)2SnBr6 with weak HB interactions exhibits only STE emission, while the (MeH)2SnBr6 exhibits both STE and charge transfer exciton emissions owing to the strong HB interactions, resulting in an excitation-dependent emission at cryogenic conditions. Detailed structural analyses and Hirshfeld surface calculations confirm that the enhanced HB interactions are essential to obtain the multiple emissions in (MeH)2SnBr6.

Circularly Polarized Luminescence from Zero-Dimensional Hybrid Lead-Tin Bromide with Near-Unity Photoluminescence Quantum Yield.

Zero-dimensional (0D) hybrid metal halides with perfect host-guest structures are promising candidates to construct circularly polarized luminescence (CPL)-active materials. However, it still remains challenging to obtain 0D chiral metal halides with simultaneously strong CPL and high photoluminescence quantum yield. Here, a new enantiomeric pair of 0D hybrid lead-tin bromides, (RR/SS-C6 N2 H16 )2 Pb0.968 Sn0.032 Br6 ⋅ 2H2 O (R/S-PbSnBr ⋅ H2 O), is reported. The R/S-PbSnBr ⋅ H2 O compounds not only show intriguing self-trapped exciton emissions with near-unity quantum yield, but also present intense CPL with a dissymmetry factor glum of ±3.0×10-3 . Such CPL activities originate from the asymmetric [SnBr6 ]4- luminophores in R/S-PbSnBr ⋅ H2 O, due to the induced structural chirality by the organic ligands via N-H⋅⋅⋅Br hydrogen bonds. Furthermore, CPL emissions with tunable colors from R/S-PbSnBr ⋅ H2 O and dehydrated compounds are reversibly observed, which extends their chiroptical applications.

Structure and Photoluminescence Transformation in Hybrid Manganese(II) Chlorides.

Hybrid metal halides with tunable photoluminescence (PL) properties have emerged as a novel light-emitting material. Hybrid manganese halides are especially attractive due to the eco-friendly and highly emissive advantages. However, the PL tunability induced by structural modulation in manganese halides has rarely been investigated. Herein, a new one-dimensional (1D) hybrid manganese chloride, (4AMP)4ClMn3Cl13·HCl (4AMP = 4-(aminomethyl)pyridinium), where the corner-sharing octahedral manganese chloride chains of [Mn3Cl137-]∞ are surrounded by organic cations, has been prepared. The addition of Zn2+ ions into precursor solution results in the formation of zero-dimensional (0D) single crystals of (4AMP)Zn1-xMnxCl4·H2O (x = 0-1) with isolated [Zn1-xMnxCl42-] tetrahedral geometry. This structural transformation leads to the PL conversion from red to green emission with an increase of photoluminescence quantum yield (PLQY) from 4.9% to 12.7%. Moreover, the incorporation of other transition metal ions (e.g., Zn2+, Co2+, and Cu2+) reveals the concentration-dependent structure modulation, where the 1D to 0D structure transformations are achieved upon the introduction of these transition metal ions at high concentrations. This work provides a new strategy to modulate the structure and luminescence in manganese halides with tunable PL properties, which could be expanded to other hybrid metal halides.

Self-assembly of anisotropic nanoparticles into functional superstructures.

Self-assembly of colloidal nanoparticles (NPs) into superstructures offers a flexible and promising pathway to manipulate the nanometer-sized particles and thus make full use of their unique properties. This bottom-up strategy builds a bridge between the NP regime and a new class of transformative materials across multiple length scales for technological applications. In this field, anisotropic NPs with size- and shape-dependent physical properties as self-assembly building blocks have long fascinated scientists. Self-assembly of anisotropic NPs not only opens up exciting opportunities to engineer a variety of intriguing and complex superlattice architectures, but also provides access to discover emergent collective properties that stem from their ordered arrangement. Thus, this has stimulated enormous research interests in both fundamental science and technological applications. This present review comprehensively summarizes the latest advances in this area, and highlights their rich packing behaviors from the viewpoint of NP shape. We provide the basics of the experimental techniques to produce NP superstructures and structural characterization tools, and detail the delicate assembled structures. Then the current understanding of the assembly dynamics is discussed with the assistance of in situ studies, followed by emergent collective properties from these NP assemblies. Finally, we end this article with the remaining challenges and outlook, hoping to encourage further research in this field.

Pressure-Engineered Photoluminescence Tuning in Zero-Dimensional Lead Bromide Trimer Clusters.

Zero-dimensional (0D) hybrid metal halides are promising light emitters. However, it is still challenging to accurately design their structures with targeted photoluminescence properties. Herein, high pressure is used to change the self-trapped exciton (STE) emission of 0D (bmpy)9 [ZnBr4 ]2 [Pb3 Br11 ] (bmpy: 1-butyl-1-methylpyrrolidinium). Under initial compression, the simultaneous contraction and distortion of photoactive [Pb3 Br11 ]5- vary the equilibrium of STE emissions between different excited states, tuning the emission color from yellow green to cyan. Notably, sufficient structural distortion under continuous compression leads to the formation of more and deeper STE states, exhibiting an unprecedented broadband white-light emission. This study reveals the structure-dependent optical properties of 0D hybrid metal halides, providing novel insights into the mechanism of STE emission.

0D Cs3 Cu2 X5 (X = I, Br, and Cl) Nanocrystals: Colloidal Syntheses and Optical Properties.

0D lead-free metal halide nanocrystals (NCs) are an emerging class of materials with intriguing optical properties. Herein, colloidal synthetic routes are presented for the production of 0D Cs3 Cu2 X5 (X = I, Br, and Cl) NCs with orthorhombic structure and well-defined morphologies. All these Cs3 Cu2 X5 NCs exhibit broadband blue-green photoluminescence (PL) emissions in the range of 445-527 nm with large Stokes shifts, which are attributed to their intrinsic self-trapped exciton (STE) emission characteristics. The high PL quantum yield of 48.7% is obtained from Cs3 Cu2 Cl5 NCs, while Cs3 Cu2 I5 NCs exhibit considerable air stability over 45 days. Intriguingly, as X is changed from I to Br and Cl, Cs3 Cu2 X5 NCs exhibit a continuous redshift of emission peaks, which is contrary to the blueshift in CsPbX3 perovskite NCs.

A Borocarbonitride Ceramic Aerogel for Photoredox Catalysis.

Borocarbonitride (BCN) is a new type of photocatalyst, but bulk BCN shows a large band gap, and low surface area, and moderate activity for photocatalysis. Here, a three-dimensional (3D) porous ceramic BCN aerogel was developed as an effective photocatalyst for relevant reactions. The unique structures endow the aerogel with an adjustable band gap and a high surface area, excellent stability, and improved crystallinity, which accelerates the separation and transfer of electron-hole pairs and promotes catalytic kinetics, thus enhancing the performance of photocatalytic reactions for hydrogen generation and carbon dioxide reduction. This work supplies a low-cost, convenient and green synthesis method for building ceramic aerogels, and it provides a simple colloid chemistry strategy combined with boron-containing compounds to facilitate further innovative breakthroughs in the novel ceramic aerogel materials design and development in the field of catalysis.

Layered Heterostructures of Ultrathin Polymeric Carbon Nitride and ZnIn2 S4 Nanosheets for Photocatalytic CO2 Reduction.

The rational construction of heterostructures by using layered semiconductors with two-dimensional (2D) nanosheet configurations is promising to improve the efficiency of CO2 photoreduction. Herein, the fabrication of layered heterojunction photocatalysts (PCN/ZnIn2 S4 ) by in situ growth of 2D ZnIn2 S4 nanosheets on the surfaces of ultrathin polymeric carbon nitride (PCN) layers is presented for greatly enhanced CO2 conversion with visible light. The solution-processed self-assembly strategy renders the building of uniform and intimate junctions between PCN layers and ZnIn2 S4 subunits, which remarkably accelerates the separation and transfer of photogenerated charge carriers. In addition, the layered composites can also promote CO2 adsorption and strengthen the visible-light absorption. Consequently, the optimized PCN/ZnIn2 S4 sheet-shaped composite shows reinforced photoactivity for deoxygenative CO2 conversion, affording a high CO-production rate of 44.6 µmol h-1 , which is 223 times higher than that of the pristine PCN nanosheets. Moreover, the heterojunction photocatalyst also exhibits high stability during repeated runs for five cycles.

Growth of Au-Pd2Sn Nanorods via Galvanic Replacement and Their Catalytic Performance on Hydrogenation and Sonogashira Coupling Reactions.

Colloidal Pd2Sn and Au-Pd2Sn nanorods (NRs) with tuned size were produced by the reduction of Pd and Sn salts in the presence of size- and shape-controlling agents and the posterior growth of Au tips through a galvanic replacement reaction. Pd2Sn and Au-Pd2Sn NRs exhibited high catalytic activity toward quasi-homogeneous hydrogenation of alkenes (styrene and 1-octene) and alkynes (phenylacetylene and 1-octyne) in dichloromethane. Au-Pd2Sn NRs showed higher activity than Pd2Sn for 1-octene, 1-octyne, and phenylacetylene. In Au-Pd2Sn heterostructures, X-ray photoelectron spectroscopy evidenced an electron donation from the Pd2Sn NR to the Au tips. Such heterostructures showed distinct catalytic behavior in the hydrogenation of compounds containing a triple bond such as tolan. This can be explained by the aurophilicity of triple bonds. To further study this effect, Pd2Sn and Au-Pd2Sn NRs were also tested in the Sonogashira coupling reaction between iodobenzene and phenylacetylene in N, N-dimethylformamide. At low concentration, this reaction provided the expected product, tolan. However, at high concentration, more reduced products such as stilbene and 1,2-diphenylethane were also obtained, even without the addition of H2. A mechanism for this unexpected reduction is proposed.

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO2 reduction.

The development of efficient, robust and earth-abundant catalysts for photocatalytic conversions has been the Achilles' heel of solar energy utilization. Here, we report on a chemical approach based on ligand designed architectures to fabricate unique structural molecular catalysts coupled with appropriate light harvesters (e.g., carbon nitride and Ru(bpy)32+) for photoredox reactions. The "Co4O4" cubane complex Co4O4(CO2Me)4(RNC5H4)4 (R = CN, Br, H, Me, OMe), serves as a molecular catalyst for the efficient and stable photocatalytic water oxidation and CO2 reduction. A comprehensive structure-function analysis emerged herein, highlights the regulation of electronic characteristics for a molecular catalyst by selective ligand modification. This work demonstrates a modulation method for fabricating effective, stable and earth-abundant molecular catalysts, which might facilitate further innovation in the function-led design and synthesis of cubane clusters for photoredox reactions.

Electron doping in bottom-up engineered thermoelectric nanomaterials through HCl-mediated ligand displacement.

A simple and effective method to introduce precise amounts of doping in nanomaterials produced from the bottom-up assembly of colloidal nanoparticles (NPs) is described. The procedure takes advantage of a ligand displacement step to incorporate controlled concentrations of halide ions while removing carboxylic acids from the NP surface. Upon consolidation of the NPs into dense pellets, halide ions diffuse within the crystal structure, doping the anion sublattice and achieving n-type electrical doping. Through the characterization of the thermoelectric properties of nanocrystalline PbS, we demonstrate this strategy to be effective to control charge transport properties on thermoelectric nanomaterials assembled from NP building blocks. This approach is subsequently extended to PbTe(x)Se(1-x)@PbS core-shell NPs, where a significant enhancement of the thermoelectric figure of merit is achieved.

Size and aspect ratio control of Pd2Sn nanorods and their water denitration properties.

Monodisperse Pd2Sn nanorods with tuned size and aspect ratio were prepared by co-reduction of metal salts in the presence of trioctylphosphine, amine, and chloride ions. Asymmetric Pd2Sn nanostructures were achieved by the selective desorption of a surfactant mediated by chlorine ions. A preliminary evaluation of the geometry influence on catalytic properties evidenced Pd2Sn nanorods to have improved catalytic performance. In view of these results, Pd2Sn nanorods were also evaluated for water denitration.

Cu2ZnSnS4-Ag2S Nanoscale p-n Heterostructures as Sensitizers for Photoelectrochemical Water Splitting.

A cation exchange-based route was used to produce Cu2ZnSnS4 (CZTS)-Ag2S nanoparticles with controlled composition. We report a detailed study of the formation of such CZTS-Ag2S nanoheterostructures and of their photocatalytic properties. When compared to pure CZTS, the use of nanoscale p-n heterostructures as light absorbers for photocatalytic water splitting provides superior photocurrents. We associate this experimental fact to a higher separation efficiency of the photogenerated electron-hole pairs. We believe this and other type-II nanoheterostructures will open the door to the use of CZTS, with excellent light absorption properties and made of abundant and environmental friendly elements, to the field of photocatalysis.

Cu(2)ZnSnS(4)-Pt and Cu(2)ZnSnS(4)-Au heterostructured nanoparticles for photocatalytic water splitting and pollutant degradation.

Cu2ZnSnS4, based on abundant and environmental friendly elements and with a direct band gap of 1.5 eV, is a main candidate material for solar energy conversion through both photovoltaics and photocatalysis. We detail here the synthesis of quasi-spherical Cu2ZnSnS4 nanoparticles with unprecedented narrow size distributions. We further detail their use as seeds to produce CZTS-Au and CZTS-Pt heterostructured nanoparticles. Such heterostructured nanoparticles are shown to have excellent photocatalytic properties toward degradation of Rhodamine B and hydrogen generation by water splitting.

Synthesis of borocarbonitride nanosheets from biomass for enhanced charge separation and hydrogen production.

Borocarbonitride (BCN) materials have shown significant potential as photocatalysts for hydrogen production. However, traditional bulk BCN exhibits only moderate photocatalytic activity. In this study, we introduce an environmentally conscious and sustainable strategy utilizing biomass-derived carbon sources to synthesize BCN nanosheets. The hydrogen evolution efficiency of BCN-A nanosheets (110 µmol h-1 g-1) exceeds that of bulk BCN photocatalysts (12 µmol h-1 g-1) by 9.1 times, mainly due to the increased surface area (205 m2g-1) and the presence of numerous active sites with enhanced charge separation capabilities. Notably, the biomass-derived BCN nanosheets offer key advantages such as sustainability, cost-effectiveness, and reduced carbon footprint during hydrogen production. These findings highlight the potential of biomass-based BCN nanomaterials to facilitate a greener and more efficient route to hydrogen energy, contributing to the global transition towards renewable energy solutions.