Lead-free, all-inorganic halide nanocrystals hold promise for advanced devices, with chloride-based variants offering stability, tunable band gaps, and easy processing. However, these nanocrystals face synthesis challenges due to the low solubility and complex coordination of heavy metal chloride salts. The conventional ligand-assisted reprecipitation (LARP) method is incompatible with chloride-based crystals, while the hot-injection technique is slow and complex, hindering efficient synthesis and scalability. We present a modified LARP method using an acid-mediated strategy to synthesize undoped and Sb3+-doped Rb3InCl6 nanocrystals. These nanocrystals maintain colloidal stability for up to 6 months and exhibit a large Stokes shift (230 nm), a high photoluminescence quantum yield (PLAY) of 68.01%, low self-absorption, and a high light yield of 15,500 photons/MeV. The flexible nanocrystal composite film with polysulfone achieves an X-ray imaging resolution of 18.5 line pairs per millimeter (lp mm--1-1). The colloidal solution and film of Rb3InCl6:Sb nanocrystals exhibit strong radioluminescence and linear responses under X-ray irradiation, highlighting their potential for medical radiography.

The instability and toxicity of lead halide perovskites hinder their widespread application, despite their potential as novel X-ray materials. Organic-metal halide hybrids are promising luminescent materials with exceptional properties and low-temperature processing for cost-effective, eco-friendly, and high-performance alternatives. Here, we present lead-free, zero-dimensional hybrid halides, methyl triphenyl phosphonium manganese(ii) chloride ((MTP)2MnCl4) and phenyltrimethylammonium manganese(ii) chloride ((PTA)2MnCl4), grown sustainably by solution processing, in the form of large aggregated single crystals. The crystals have exceptionally high photoluminescence quantum yields of approximately 74.61% and 72.62%, showing strong green emission peaks at 512 nm and 525 nm, respectively. The crystalline materials featured 160 nm and 175 nm Stokes shifts, 40 840 and 29 500 photons per MeV high scintillation yields, and 144.65 and 594.06 nGy s-1, exceptional detection limits, respectively, revealing a self-absorption-free nature. Proving practical value, a flexible X-ray scintillator screen from a composite of poly(methyl methacrylate) and (MTP)2MnCl4 powder achieved an outstanding spatial resolution of 20 lp per mm, further cementing their viability as X-ray scintillators by being both environmentally friendly and highly effective.

Terbium-doped gadolinium oxysulfide (Gd2O2S:Tb3+), commonly referred to as Gadox, is a widely used scintillator material due to its exceptional X-ray attenuation efficiency and high light yield. However, Gadox-based scintillators suffer from low X-ray spatial resolution due to their large particle size, which causes significant light scattering. To address this limitation, we report the synthesis of terbium-doped colloidal Gadox nanoplatelets (NPLs) with near-unity photoluminescence quantum yield (PLQY) and high radioluminescence light yield (LY). In particular, our investigation reveals a strong correlation between PLQY, LY, particle size, and Tb(3+)concentration. Our synthetic approach allows precise control over the lateral size and thickness of the Gadox NPLs, resulting in a LY of 50,000 photons/MeV. Flexible scintillating screens fabricated with the solution-processable Gadox NPLs exhibited a 20 lp/mm X-ray spatial resolution, surpassing commercial Gadox scintillators. These high-performance and flexible Gadox NPL-based scintillators enable enhanced X-ray imaging capabilities in medicine and security. Our work provides a framework for designing nanomaterial scintillators with superior spatial resolution and efficiency through precise control of dimensions and dopant concentration.

Surface chemistry plays an essential role in gas-sensing applications, enabling significant improvements in the sensing performance. This study investigates the influence of the graphene oxide (GO) synthesis route on the sensitivity to NO 2 gas at room temperature (25 degrees C) and 100 degrees C in a dry and humid atmosphere. GO powders were synthesized using both the classical Hummers ' method (HGO), and an improved version of the Hummers ' method (IGO) using a mixture of phosphoric and sulfuric acids. The subsequent reduction (resulting in rHGO and rIGO, respectively) aimed to enhance the electrical properties and procure nanomaterials sensitive to surface adsorbates. In contrast to the HGO, both IGO and rIGO samples exhibited a transient sensor response and an outstanding recovery performance, which was attributed to the existence of phosphate groups in the latter samples. Notably, the rIGO sample achieved a 23 -fold increase in response to NO 2 compared to rHGO. Additionally, the limit of detection (LOD) was calculated to be 0.98 ppb at 100 degrees C. Computational studies considering models of GO and of GO with phosphorus-containing species demonstrate that the presence of the latter, either at the surface or below the surface, leads to a four-fold increase in the NO 2 adsorption energies, hence accounting for the significant enhancement in the sensing performance observed experimentally. This underscores the importance of tailoring the structure and chemical properties of GO/rGO materials for optimal performance in gas sensing applications.

Shortwave infrared (SWIR) light emitters and detectors are crucial in numerous applications. Conventionally, SWIR devices rely on epitaxially grown narrow bandgap semiconductors, such as InGaAs, which are expensive to fabricate and difficult to integrate with silicon complementary metal-oxide-semiconductors (CMOS). Colloidal quantum dots (CQDs) have emerged as low-cost alternatives to epitaxially grown semiconductors, offering integration with CMOS through solution-processing methods. However, the predominant SWIR-active CQD systems rely on heavy-metal-containing compositions (PbS and HgTe), hindering the adoption of CQD SWIR technology. InAs CQDs are promising substitutes in SWIR applications. However, synthesizing SWIR-active InAs CQDs is challenging, often constraining them to the visible or near-infrared regions. To achieve SWIR bandgaps, large InAs CQDs are typically required; such CQDs are prone to having surface traps that quench photogenerated charge carriers, adversely affecting device performance. Here, we report a two-step synthesis of surface-passivated SWIR-active InAs/ZnSe core/shell colloidal nanorod quantum dots (CNQDs). These surface-passivated CNQDs are highly emissive and tunable over the entire technologically important region (1200-1800 nm) of the SWIR window with photoluminescence quantum yields as high as 60%. Using these SWIR-active InAs/ZnSe CNQDs, we demonstrated an SWIR-active InAs CQD photodetector, achieving a record high external quantum efficiency of similar to 15% at similar to 1450 nm and a low dark current of similar to 10-2 mA/cm(2).

Organic-inorganic atomically precise nanoclusters provide indispensable building blocks for establishing structure-property links in hybrid condensed matter. However, robust glasses of ligand-protected nanocluster solids have yet to be demonstrated. Herein, we show [Cu4I4(PR3)(4)] cubane nanoclusters coordinated by phosphine ligands (PR3) form robust melt-quenched glasses in air with reversible crystal-liquid-glass transitions. Protective phosphine ligands critically influence the glass formation mechanism, modulating the glasses' physical properties. A hybrid glass utilizing ethyldiphenylphosphine-based nanoclusters, [Cu4I4(PPh2Et)(4)], exhibits superb optical properties, including >90% transmission in both visible and near-infrared wavelengths, negligible self-absorption, near-unity quantum yield, and high light yield. Experimental and theoretical analyses demonstrate the structural integrity of the [Cu4I4(PPh2Et)(4)] nanocluster, i.e., iodine-bridged tetranuclear cubane, has been fully preserved in the glass state. The strong internanocluster CH-pi interactions found in the [Cu4I4(PPh2Et)(4)] glass and subsequently reduced structural vibration account for its enhanced luminescence properties. Moreover, this highly transparent glass enables performant X-ray imaging and low-loss waveguiding in fibers drawn above the glass transition. The discovery of "nanocluster glass" opens avenues for unraveling glass formation mechanisms and designing novel luminescent glasses of well-defined building blocks for advanced photonics.

Point defects in nanoparticles have long been hypothesized to play an important role in governing the particle's electronic structure and physicochemical properties. However, single point defects in material systems usually exist with other heterogeneities, obscuring the chemical role of the effects. Herein, we report the synthesis of novel atomically precise, copper hydride nanoclusters (NCs), [Cu28 H10 (C7 H7 S)18 (TPP)3 ] (Cu28 ; TPP: triphenylphosphine; C7 H7 S: o-thiocresol) with a defined defect in the gram scale via a one-pot reduction method. The Cu28 acts as a highly selective catalyst for C-C cross-couplings. The work highlights the potential of defective NCs as model systems for investigating individual defects, correlating defects with physiochemical properties, and rationally designing new nanoparticle catalysts.

One of the most effective approaches to optimizing the performance of perovskite solar cells is to fully understand the ultrafast carrier dynamics at the interfaces between absorber and transporting layers at both the molecular and atomic levels. Here, the injection dynamics of hot and relaxed charge carriers at the interface between the hybrid perovskite, formamidinium lead bromide (FAPbBr(3)), and the organic electron acceptor, IEICO-4F, are investigated and deciphered by using femtosecond (fs) mid-infrared (IR), transient absorption (TA), and fluorescence spectroscopies. The visible femtosecond-TA measurements reveal the generation of hot carriers and their transition to free carriers in the pure FAPbBr3 film. Meanwhile, the efficient extraction of hot carriers in the mixed FAPbBr(3)/IEICO-4F film is clearly evidenced by the complete disappearance of their spectral signature. More specifically, the time-resolved results reveal that hot carriers are injected from FAPbBr3 to IEICO-4F within 150 fs, while the transfer time for the relaxed carriers is about 205 fs. The time-resolved mid-IR experiments also demonstrate the ultrafast formation of two peaks at 2115 and 2233 cm(-1), which can be attributed to the C N symmetrical and asymmetrical vibrational modes of anionic IEICO-4F, thus providing crystal clear evidence for the electron transfer process between the donor and acceptor units. Moreover, photoluminescence (PL) lifetime measurements reveal an approximately 10-fold decrease in the donor lifetime in the presence of IEICO-4F, thereby confirming the efficient electron injection from the perovskite to the acceptor unit. In addition, the efficient electron injection at the FAPbBr(3)/IEICO-4F interface and its impact on the C N bond character are experimentally evidenced and align with density functional theory (DFT) calculations. This work offers new insights into the electron injection process at the FAPbBr(3)/IEICO-4F interface, which is crucial for developing efficient optoelectronic devices.

Porous biomass-based chars are promising active materials for the adsorption of greenhouse gases such as carbon dioxide. In the Middle East, an exceptionally abundant biomass resource is the date palm tree, for which reason there is an increasing interest in using its fruit pits as bio-char precursors. We designed a KOH-activated carbon-carbon powder, constituted by a mixture of two components, reduced graphene oxide (rGO) and a palm date seeds (bio-)char, and investigated its performance in capturing CO2 gas. The optimised mixture had a specific surface area of 845 m2/g, with 92% of the pore volume attributed to microporosity, and a CO2 adsorption capacity (at 0 °C, 1 bar) of 3.4 mmol/g. Given the observed “sorption dampening” action of the rGO, it effectively acted as an indirect probe on how the CO2 uptake is impacted by the presence of potassium. Here, we suggest that the alkali metal cations, intercalated at the surface graphene layers, improve the CO2 adsorption capacity of the activated bio-char component.

Despite growing interest in lead-halide perovskites for visible-light communication (VLC), the health concerns associated with lead hinder their widespread application. Herein, we demonstrate for the first time a lead-free perovskite phosphor-based VLC link using an ultraviolet-micro-LED, achieving 84.9 CRI, 4115-K CCT, and 1.5-Mb/s data rate.

Carbon cathodes have shown excellent electrochemical behavior in aluminum batteries based on non‐aqueous electrolytes. By contrast, their use in Al systems operating in a salt‐water medium is plagued by poor and unstable performance. Herein, it is sustained that a successful C cathode for rechargeable aqueous Al batteries requires surface customization to enable hydrophilicity and grafting of charged Al molecules. Employing a freeze‐dried reduced graphene oxide (rGO) as the active electrode material, an aqueous Al‐C battery is assembled with a high energy density (136 Wh kg−1 per cathode mass) and one of the best capacity retentions reported (≈60% across a range of current densities and constant Coulombic efficiencies close to unit). Furthermore, the rGO cathode more than doubles the benchmark for life cycles (to ≈200 cycles) and can be charged rapidly (<5 min). To explain this response, a charge storage mechanism is proposed wherein the [Al(H2O)6]3+ ions do not get desolvated when inserted into the cathode. The guest Al ions (surface adsorbed or intercalated) act as proton donors and may get anchored on the oxygen moieties of the rGO, further promoting the formation of an electrochemical double layer. A mixed charge‐storage regime follows that stabilizes the carbon cathode and enables an unprecedented response.

Mn4+-doped fluorides are a growing class of narrow-band red-emitting phosphors for lighting and display technologies. However, we lack a method for synthesizing these materials as colloidal nanocrystals (NCs), making their solution processing difficult and limiting their potential applications. Herein, we propose a colloidal approach to the preparation of Mn4+-doped inorganic hexafluoride (A(x)B ' F-6:Mn4+, in which A = K, Cs and B ' = Al, Si, Sn) NCs with narrow size distributions. Our method can be extended to different matrices and dopant compositions. Furthermore, it permits the fine-tuning of the Mn4+ concentration in the NCs. The A(x)B ' F-6:Mn4+ NCs exhibit narrow-band bright-red emission with a photoluminescence quantum yield of up to similar to 73% and long-term stability, and they can form colloidal solutions in various polar and nonpolar solvents. The solution processability of the NCs and their small size enabled the fabrication of transparent and flexible NC-polymer composite films, which we were fashioned into X-ray imaging scintillators. These scintillators exhibit excellent performance with a high X-ray imaging resolution of 20 lp/mm, and a relatively low detection limit of 720 nGy/s. Our synthesis strategy makes way for the exploration of a new class of red-emitting colloidal NCs for various downconversion applications.

The process of carbon dioxide capture and storage is seen as a critical strategy to mitigate the so-called greenhouse effect and the planetary climate changes associated with it. In this study, we investigated the CO2 adsorption capacity of various microporous carbon materials originating from palm date seeds (PDS) using green chemistry synthesis. The PDS was used as a precursor for the hydrochar and activated carbon (AC). Typically, by using the hydrothermal carbonization (HTC) process, we obtained a powder that was then subjected to an activation step using KOH, H3PO4 or CO2, thereby producing the activated HTC-PDS samples. Beyond their morphological and textural characteristics, we investigated the chemical composition and lattice ordering. Most PDS-derived powders have a high surface area (>1000 m2 g−1) and large micropore volume (>0.5 cm3 g−1). However, the defining characteristic for the maximal CO2 uptake (5.44 mmol g−1, by one of the alkaline activated samples) was the lattice restructuring that occurred. This work highlights the need to conduct structural and elemental analysis of carbon powders used as gas adsorbents and activated with chemicals that can produce graphite intercalation compounds.