Carbonized Polymer Dots for Controlling Construction of MoS2 Flower-Like Nanospheres to Achieve High-Performance Li/Na Storage Devices.

Despite being one of the most promising materials in anode materials, molybdenum sulfide (MoS2 ) encounters certain obstacles, such as inadequate cycle stability, low conductivity, and unsatisfactory charge-discharge (CD) rate performance. In this study, a novel approach is employed to address the drawbacks of MoS2 . Carbon polymer dots (CPDs) are incorporated to prepare three-dimensional (3D) nanoflower-like spheres of MoS2 @CPDs through the self-assembly of MoS2 2D nanosheets, followed by annealing at 700 °C. The CPDs play a main role in the creation of the nanoflower-like spheres and also mitigate the MoS2 nanosheet limitations. The nanoflower-like spheres minimize volume changes during cycling and improve the rate performance, leading to exceptional rate performance and cycling stability in both Lithium-ion and Sodium-ion batteries (LIBs and SIBs). The optimized MoS2 @CPDs-2 electrode achieves a superb capacity of 583.4 mA h g-1 at high current density (5 A g-1 ) after 1000 cycles in LIBs, and the capacity remaining of 302.8 mA h g-1 after 500 cycles at 5 A g-1 in SIBs. Additionally, the full cell of LIBs/SIBs exhibits high capacity and good cycling stability, demonstrating its potential for practical application in fast-charging and high-energy storage.

Dispersing small Ru nanoparticles into boron nitride remodified by reduced graphene oxide for high-efficient electrocatalytic hydrogen evolution reaction.

Ruthenium (Ru) electrocatalysts suffer from excessive aggregation during the hydrogen evolution reaction (HER), which hinders their practical application for hydrogen production. Hexagonal boron nitride (h-BN) is a potential carrier that could solve the above problem, but its wide band gap and low conductivity become obstacles. Herein, we provide a new, facile, low-cost, and effective strategy (killing two birds with one stone) to overcome the above issues. After modifying h-BN with reduced graphene oxide (rGO), a small amount of Ru nanoparticles (NPs) (2.2 %) are dispersed into BN with approximately uniform distribution and size control of Ru nanoparticles (∼3.85 nm). The strong synergy between Ru NPs and BN@C in the optimal Ru/BN@C (Ru wt.% = 2.22 %) electrocatalyst endows it an outstanding HER activity, with small HER overpotentials (η10 = 32 mV, 35 mV) and low Tafel slopes (33.89 mV dec-1, 37.66 mV dec-1) in both 1 M KOH and 0.5 M H2SO4 media, respectively, along with good long-term stability for 50 h. Based on density functional theory (DFT) calculations, the addition of Ru to BN has been successful in creating fresh active sites for H*, with good possible adsorption/desorption ability (ΔGH* = -0.24 eV) while preserving low water dissociation (ΔGb = 0.46 eV) in an alkaline environment. As a result, the Ru/BN composite exhibits outstanding HER activity in both acidic and alkaline conditions. Furthermore, this study provides, for the first time, a template-free strategy to develop a good and low-cost supporter (BN) for dispersing other noble metals and the formation of highly efficient HER/OER electrocatalysts.

Hydrogel Nanocomposite-Derived Nickel Nanoparticles/Porous Carbon Frameworks as Non-Precious and Effective Electrocatalysts for Methanol Oxidation.

Innovative and facile methods for the preparation of metal nanoparticles (MNPs) with A highly uniform distribution and anchored on a unique substrate are receiving increasing interest for the development of efficient and low-cost catalysts in the field of alternative and sustainable energy technologies. In this study, we report a novel and facile metal-ions adsorption-pyrolysis method based on a hydrogel nanocomposite for the preparation of well-distributed nickel nanoparticles on 3D porous carbon frameworks (Ni@PCFs). The pyrolysis temperature effect on electrocatalytic activity toward methanol oxidation and catalyst stability was investigated. Physicochemical characterizations (SEM, TEM, and XRD) were used to determine the morphology and composition of the prepared electrocatalyst, which were then linked to their electrocatalytic activity. The experimental results indicate that the catalyst synthesized by pyrolysis at 800 °C (Ni@PCFs-8) exhibits the highest electrocatalytic activity for oxidation of methanol in alkaline media. Additionally, prepared Ni@PCFs-8 displays a remarkable increase in electrocatalytic activity after activation in 1 M KOH and excellent stability. The adsorption-pyrolysis pathway ensures that the Ni NPs are trapped in the PCFs, which can provide highly reactive surface sites. This work may provide a facile and effective strategy for preparing uniformly distributed metallic NPs on a 3D PCF substrate with high catalytic activity for energy applications.

Pt nanoparticles supported on nitrogen-doped porous graphene for sensitive detection of Tadalafil.

Graphene (GR) is one of the most promising candidates for utilization in the electroanalytical field because of its superior electrocatalytic activity, excellent electronic conductivity, and high chemical stability. However, the GR sheets usually tend to stack together with π-π interaction. The spontaneous stacking leads to the aggregation of the GR sheets and imposes a negative feedback in the surface area of the GR, which obviously limits its electrochemical application. In this study, nitrogen-doped porous GR (NPGR) with different pore sizes is prepared by using silica (SiO2) as a template. The NPGR exhibits high surface area and porous structure, fulfilling the requirement for supporting materials. Being a support, the structural uniqueness and N dopants of NPGR facilitate the deposition of Pt nanoparticles (Pt NPs). The Pt NPs/NPGR composites integrate the structural properties of NPGR and catalytic properties of Pt NPs. A selective and sensitive electrochemical sensor was successfully developed for sensitive determination of Tadalafil (TAD), showing a concentration range of 1.30-488.9µM and limit of detection of 0.268µM.