Facial Grinding Method for Synthesis of High-Purity CuS Nanosheets

Sulfur Defect Tuning of CuS/BiVO4 and Understanding the Function of Hydrogen Radicals for Photoelectrochemical Ammonia Production

Photoelectrochemical nitrate reduction has been a promising method for ammonia (NH3) production under normal temperatures and neutral conditions. However, hydrogenation is a key process in the selective production of NH3 during nitrate reduction; therefore, inducing the active hydrogen for nitrate hydrogenation and inhibiting hydrogen production are a noteworthy problem. In this study, BiVO4/CuS (BVO/CS) heterostructure has been constructed for a photoelectrochemical nitrate reduction reaction (PEC NIRR). The introduction of CuS optimizes the electron-transfer ability and enhances the surface catalytic kinetics of BVO/CS. At the same time, the presence of sulfur vacancies on the surface promotes the adsorption and activation of nitrate, realizes the splitting of H2O, and successfully generates abundant hydrogen radicals (H*). The generated H* is effectively utilized in the hydrogenation of NIRR. The NH3 yield and selectivity of optimal BVO/CS reach 30.55 μg h-1 cm-2 and 43.8%, respectively, which are 2.65 and 2.39 times that of bare BVO. Therefore, this work determines the key role of H* for nitrate hydrogenation, providing a novel strategy for boosting PEC NIRR. CuS/BiVO4 was successfully fabricated for photoelectrochemical nitrate reduction. Sulfur defects enabled the generation of hydrogen radicals, which effectively promoted nitrate hydrogenation and NH3 production.

Near-infrared-responsive CuS@Cu-MOF nanocomposite with high foliar retention and extended persistence for controlling strawberry anthracnose

Strawberry anthracnose (Colletotrichum gloeosporioides) exhibits a high pathogenicity, capable of directly infecting leaves through natural openings, resulting in devastating impacts on strawberries. Here, nanocomposite (CuS@Cu-MOF) was prepared with a high photothermal conversion efficiency of 35.3% and a strong response to near-infrared light (NIR) by locally growing CuS nanoparticles on the surface of a copper-based metal-organic framework (Cu-MOF) through in situ sulfurization. The porosity of Cu-MOF facilitated efficient encapsulation of the pesticide difenoconazole within CuS@Cu-MOF (DIF/CuS@Cu-MOF), achieving a loading potential of 19.18 ± 1.07%. Under NIR light irradiation, DIF/CuS@Cu-MOF showed an explosive release of DIF, which was 2.7 times higher than that under dark conditions. DIF/CuS@Cu-MOF exhibited a 43.9% increase in efficacy against C. gloeosporioides compared to difenoconazole microemulsion (DIF ME), demonstrating prolonged effectiveness. The EC50 values for DIF and DIF/CuS@Cu-MOF were 0.219 and 0.189 μg/mL, respectively. Confocal laser scanning microscopy demonstrated that the fluorescently labeled CuS@Cu-MOF acted as a penetrative carrier for the uptake of hyphae. Furthermore, DIF/CuS@Cu-MOF exhibited more substantial resistance to rainwater wash-off than DIF ME, with retention levels on the surfaces of cucumber leaves (hydrophilicity) and peanut leaves (hydrophobicity) increasing by 36.5-fold and 9.4-fold, respectively. These findings underscore the potential of nanocomposite to enhance pesticide utilization efficiency and leaf retention.

Nanomaterial with Core-Shell Structure Composed of {P2W18O62} and Cobalt Homobenzotrizoate for Supercapacitors and H2O2-Sensing Applications

Designing and preparing dual-functional Dawson-type polyoxometalate-based metal-organic framework (POMOF) energy storage materials is challenging. Here, the Dawson-type POMOF nanomaterial with the molecular formula CoK₄[P₂W₁₈O₆₂]@Co₃(btc)₂ (abbreviated as {P₂W₁₈}@Co-BTC, H₃btc = 1,3,5-benzylcarboxylic acid) was prepared using a solid-phase grinding method. XRD, SEM, TEM et al. analyses prove that this nanomaterial has a core-shell structure of Co-BTC wrapping around the {P₂W₁₈}. In the three-electrode system, it was found that {P₂W₁₈}@Co-BTC has the best supercapacitance performance, with a specific capacitance of 490.7 F g^-1 (1 A g^-1) and good stability, compared to nanomaterials synthesized with different feedstock ratios and two precursors. In the symmetrical double-electrode system, both the power density (800.00 W kg^-1) and the energy density (11.36 Wh kg^-1) are greater. In addition, as the electrode material for the H₂O₂ sensor, {P₂W₁₈}@Co-BTC also exhibits a better H₂O₂-sensing performance, such as a wide linear range (1.9 μM-1.67 mM), low detection limit (0.633 μM), high selectivity, stability (92.4%) and high recovery for the detection of H₂O₂ in human serum samples. This study provides a new strategy for the development of Dawson-type POMOF nanomaterial compounds.

Constructing NCuS Interface Chemical Bonds over SnS2 for Efficient Solar-Driven Photoelectrochemical Water Splitting

The restricted charge transfer and slow oxygen evolution reaction (OER) dynamics tremendously hamper the realistic implementation of SnS₂ photoanodes for photoelectrochemical (PEC) water splitting. Here, a novel strategy is developed to construct interfacial NCuS bonds between NC skeletons and SnS₂ (CuNC@SnS₂ ) for efficient PEC water splitting. Compared with SnS₂ , the PEC activity of CuNC@SnS₂ photoelectrode is tremendously heightened, obtaining a current density of 3.40 mA cm² at 1.23 V_RHE with a negatively shifted onset potential of 0.04 V_RHE , which is 6.54 times higher than that of SnS₂ . The detailed experimental characterizations and theoretical calculation demonstrate that the interfacial NCuS bonds enhance the OER kinetic, reduce the surface overpotential, facilitate the separation of photon-generated carriers, and provide a fast transmission channel for electrons. This work presents a new approach for modulating charge transfer by interfacial bond design in heterojunction photoelectrodes toward promoting PEC performance and solar energy application.

A high-performance Cu-Al dual-ion battery realized by high-concentration Cl- electrolyte and CuS cathode

We propose a new Cu-Al dual-ion battery that aqueous solution composed of LiCl, CuCl and AlCl3 (LiCuAl) is used as the electrolyte, CuS is used as the cathode of aqueous aluminum ion battery for the first time and copper foil is used as the anode. The assembled Cu-Al dual-ion battery yields a reversible capacity of 538 mA h/g at 200 mA/g, and exhibits longterm cycling stability of over 200 cycles with 88.6% capacity retention at 1000 mA/g. Above excellent performance is inseparable from the three components of LiCuAl electrolyte and electrode materials. The Al-storage mechanism of CuS is proposed that the S-S bond in CuS lattice interacts with aluminum ions during the aluminum storage process. In addition, the charging and discharging process does not cause irreversible damage to the S-S bond, thus Cu-Al dual-ion battery with CuS as cathode shows great cycle stability.

Nanointerface engineering Z-scheme CuBiOS@CuBi2O4 heterojunction with OS interpenetration for enhancing photocatalytic hydrogen peroxide generation and accelerating chromium(VI) reduction

Designing a core-shell nanointerface is beneficial for enhancing the photocatalytic performance of hydrogen peroxide (H₂O₂) production. Hence, a direct Z-scheme one-dimensional (1 D) CuBiOS@CuBi₂O₄ nanorods with a core (oxide)-shell (sulfide) nanostructure and OS interpenetrated nanointerface was controllably synthesized through in-situ anion exchange. The formation of OS interpenetration at the heterogeneous interface with surface oxygen vacancies could effectively boost light absorption, reduce the interface contact resistance, facilitate band bending, and thus enhance charge separation and transfer as a "bridge". The as-prepared catalyst with tunable OS nanointerface greatly improved the photocatalytic performances in the H₂O₂ production with a yield of 201.9 μmol·L^-1 and the in-situ generated H₂O₂ effectively accelerated the reduction of chromium(VI) (Cr(VI), 95.4% within 15 min). The excellent performances were due to the OS interpenetration with rich oxygen vacancies and unique shell-core structure with intimate contact inter-doping nanointerface. Moreover, the photocatalytic mechanism was discussed in detail. This work might provide a guideline in the design and construction of high-performance catalysts with well-defined nanointerface for various applications.

Design of Double-Shelled CuS Nanocages to Optimize Electrocatalytic Dynamic for Sensitive Detection of Ascorbic Acid

Although transition metal sulfides have presented prospect in electrochemical sensing, their electrocatalytic performance still cannot meet the demands for practical applications due to the difficulties in mass transport and electron transfer. In this work, double-shelled CuS nanocages (2-CuS NCs) were prepared for enzyme-free ascorbic (AA) sensor through a Cu2O- templated method. The unique double-shelled hollow structure displayed large specific surface areas, ordered diffusion channels, increased volume occupying rate, and accelerated electron transfer rate, resulting in enhanced electrochemical dynamic. As a sensing electrode for AA, 2-CuS NCs modified glassy carbon electrode (2-CuS NCs/GCE) exhibited eminent electrocatalytic activity in terms of satisfying sensitivity (523.7 μA mM-1 cm-2), short response time (0.31 s), and low limit of detection (LOD, 0.15 μM). 2-CuS NCs look promising for analytical sensing of AA in electrochemical sensors thanks to its prominent electrocatalytic kinetics issued from double-shelled hollow porous structure.