Alkyne-Functionalized Platinum Chalcogenide (S, Se) Nanoparticles.

Metal chalcogenide nanoparticles play a vital role in a wide range of applications and are typically stabilized by organic derivatives containing thiol, amine, or carboxyl moieties, where the nonconjugated particle-ligand interfaces limit the electronic interactions between the inorganic cores and organic ligands. Herein, a wet-chemistry method is developed for the facile preparation of stable platinum chalcogenide (S, Se) nanoparticles capped with acetylene derivatives (e.g., 4-ethylphenylacetylene, EPA). The formation of Pt-C≡ conjugated bonds at the nanoparticle interfaces, which is confirmed by optical and X-ray spectroscopic measurements, leads to markedly enhanced electronic interactions between the d electrons of the nanoparticle cores and π electrons of the acetylene moiety, in stark contrast to the mercapto-capped counterparts with only nonconjugated Pt-S- interfacial bonds, as manifested in spectroscopic measurements and density functional theory calculations. This study underscores the significance of conjugated anchoring linkages in the stabilization and functionalization of metal chalcogenides, a unique strategy for diverse applications.

Defective Fe3 O4- x Few-Atom Clusters Anchored on Nitrogen-Doped Carbon as Efficient Oxygen Reduction Electrocatalysts for High-Performance Zinc-Air Batteries.

It remains a challenge to develop cost-effective, high-performance oxygen electrocatalysts for rechargeable metal-air batteries. Herein, zinc-mediated zeolitic imidazolate frameworks are exploited as the template and nitrogen and carbon sources, onto which is deposited a Fe3 O4 layer by plasma-enhanced atomic layer deposition. Controlled pyrolysis at 1000 °C leads to the formation of high density of Fe3 O4- x few-atom clusters with abundant oxygen vacancies deposited on an N-doped graphitic carbon framework. The resulting nanocomposite (Fe3 O4- x /NC-1000) exhibits a markedly enhanced electrocatalytic performance toward oxygen reduction reaction in alkaline media, with a remarkable half-wave potential of +0.930 V versus reversible hydrogen electrode, long-term stability, and strong tolerance against methanol poisoning, in comparison to samples prepared at other temperatures and even commercial Pt/C. Notably, with Fe3 O4- x /NC-1000 as the cathode catalyst, a zinc-air battery delivers a high power density of 158 mW cm-2 and excellent durability at 5 mA cm-2 with stable 2000 charge-discharge cycles over 600 h. This is ascribed to the ready accessibility of the Fe3 O4- x catalytic active sites, and enhanced electrical conductivity, oxygen adsorption, and electron-transfer kinetics by surface oxygen vacancies. Further contributions may arise from the highly conductive and stable N-doped graphitic carbon frameworks.

High-Energy-Density Asymmetric Supercapacitor Based on Free-Standing Ti3C2TX@NiO-Reduced Graphene Oxide Heterostructured Anode and Defective Reduced Graphene Oxide Hydrogel Cathode.

The rational design of an asymmetric supercapacitor (ASC) with an expanded operating voltage window has been recognized as a promising strategy to maximize the energy density of the device. Nevertheless, it remains challenging to have electrode materials that feature good electrical conductivity and high specific capacitance. Herein, a 3D layered Ti3C2TX@NiO-reduced graphene oxide (RGO) heterostructured hydrogel was successfully synthesized by uniform deposition of NiO nanoflowers onto Ti3C2TX nanosheets, and the heterostructure was assembled into a 3D porous hydrogel through a hydrothermal GO-gelation process at low temperatures. The resultant Ti3C2TX@NiO-RGO heterostructured hydrogel exhibited an ultrahigh specific capacitance of 979 F g-1 at 0.5 A g-1, in comparison to that of Ti3C2TX@NiO (623 F g-1) and Ti3C2TX (112 F g-1). Separately, a defective RGO (DRGO) hydrogel was found to exhibit a drastic increase in specific capacitance, compared to untreated RGO (261 vs 178 F g-1 at 0.5 A g-1), owing to abundant mesopores. These two materials were then used as free-standing anode and cathode to construct an ASC, which displayed a large operating voltage (1.8 V), a high energy density (79.02 Wh kg-1 at 450 W kg-1 and 45.68 Wh kg-1 at 9000 W kg-1), and remarkable cycling stability (retention of 95.6% of the capacitance after 10,000 cycles at 10 A g-1). This work highlights the unique potential of Ti3C2TX-based heterostructured hydrogels as viable electrode materials for ASCs.

Encapsulation of Pb-Free CsSnCl3 Perovskite Nanocrystals with Bone Gelatin: Enhanced Stability and Application in Fe3+ Sensing.

The toxicity of the Pb element limits the large-scale application of inorganic cesium-lead halide (CsPbX3, with X = Cl, Br, and I) perovskite nanocrystals (NCs). Pb-free cesium-tin halide (CsSnX3) NCs have emerged as a viable alternative because of its excellent photoelectric conversion efficiency. However, the applications are hampered by its poor stability and low photoluminescence quantum yield (PLQY). In this study, extraordinarily stable CsSnCl3 NCs were prepared by exploiting bone gelatin as surface capping agents, which retain 95% of the photoluminescence intensity in water for 55 h. Additionally, after bone gelatin encapsulation, the PLQY of CsSnCl3 NCs was found to increase from 2.17% to 3.13% for the uncapped counterparts because of an improved radiative recombination rate. With such remarkable optical properties of the bone gelatin-CsSnCl3 NCs, metal ions like Fe3+ in aqueous solutions can be readily detected and monitored, signifying the potential application of such stable bone gelatin-CsSnCl3 NCs in the development of fluorescence sensors and detectors.