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The design of efficient, stable and cost-effective electrocatalysts for the hydrogen evolution reaction holds substantial significance in water electrolysis, but it remains challenging. Tremella-like nickel-molybdenum bimetal phosphide encapsulated cobalt phosphide (NiMoP/CoP) with hierarchical architectures has been effectively synthesized on nickel foam (NF) via a straightforward hydrothermal followed by low-temperature phosphating method. Based on the unique structural benefits, it significantly increases the number of redox active centers, enhances the electrical conductivity of materials, and diminishes the ion diffusion path lengths, thereby promoting efficient electrolyte penetration and reducing the inherent resistance. The as-obtained NiMoP/CoP/NF electrocatalyst exhibited remarkable catalytic activity with an ultralow overpotential of 38 mV (10 mA cm−2) and low Tafel slope of 83 mV dec−1. The straightforward synthesis process and exceptional electrocatalytic properties of NiMoP/CoP/NF demonstrate great potential for the HER to replace the precious metal catalyst. [ABSTRACT FROM AUTHOR]

The preparation of an electrocatalyst for the oxygen evolution reaction (OER) with high catalytic activity, good long-term durability and rapid reaction kinetics through interface engineering is of great significance. Herein, we have developed a bimetallic sulfide particle cluster-supported three-dimensional graphene aerogel (FeNiS@GA), which serves as an efficient electrocatalyst for OER, by a one-step hydrothermal method. Profiting from the synergy of the FeNiS particle cluster with high capacitance and GA with its three-dimensional porous nanostructure, FeNiS@GA shows a high specific surface area, large pore volume, low contact resistance, and decreases the electron and ion transport routes. FeNiS@GA exhibits outstanding OER activity (when the current density is 50 mA cm−2, the overpotential is 341 mV), low Tafel slope (63.87 mV dec−1) and remarkable stability in alkaline solutions, outperforming FeNiS, NiS@GA, FeS@GA and RuO2. Due to its simple synthesis process and excellent electrocatalytic performance, FeNiS@GA shows great potential to replace noble metal-based catalysts in practical applications. [ABSTRACT FROM AUTHOR]

Efficient non-noble metal bifunctional electrocatalysts can increase the conversion rate of electric energy in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a ball & sheet MoS2/Ni3S2 composite with wide-layer-spacing and high 1T-rich MoS2 is assembled on nickel foam (NF) via a two-step solvothermal method with polymeric sulfur (S-r-DIB) as the sulfur source. The obtained material serves as both the cathode and the anode toward overall water splitting in an alkaline electrolyte. The results proved that the interpenetration of MoS2/Ni3S2-p with a ball and sheet structure increased the material active surface area and exposed more catalytic active sites, which contributed to the penetration of solution and the transfer of charge/hydrion. Meanwhile, two different semiconductors of MoS2 and Ni3S2 along with the presence of ample active sulfur edge sites and few-layer, wide-layer-spacing structures of MoS2 lead to an outstanding electrocatalytic activity. In particular, the electrodes of MoS2/Ni3S2-p only need a battery voltage of 1.55 V at 10 mA cm−2. The bifunctional electrocatalyst MoS2/Ni3S2-p also shows excellent stability at large current densities during the electrochemical test. [ABSTRACT FROM AUTHOR]

The design and synthesis of high-performance catalysts for hydrogen evolution reaction (HER) is of significant importance for electrocatalysis reaction. In this study, 0D Ag nanoparticles were successfully loaded onto 2D Ni(OH)2 nanosheets by a one-step hydrothermal method for enhancing the electrocatalytic ability. The special structure of Ni(OH)2 with only 2 wt% Ag on 3D nickel foam (NF) exhibited a high surface area and excellent charge transfer channels. Furthermore, the synergistic effect as well as the transfer of electron density between Ag and Ni(OH)2 contributed to a high HER activity. As a result, Ni(OH)2–Ag/NF exhibited excellent HER performance with an overpotential of 89 mV to obtain a current of 10 mA cm−2 in an alkaline electrolyte, 155 mV lower than that of Ni(OH)2/NF. After 10 hours of stability test and more than 1000 cycles, negligible loss of the initial catalytic activity to drive a current density of 10 mA cm−2 verified excellent stability during the alkaline HER process. This research provides a new idea to integrally construct ultralow noble metal catalysts with outstanding HER performance and results in new advances in the field of hydrogen evolution. [ABSTRACT FROM AUTHOR]

Few-layer and 1T-rich MoS2 is synthesized by a one-step solvothermal process using a rigid segment-containing polysulfide as a concomitant sulfur source and in situ intercalator. The prepared MoS2 displays superior hydrogen evolution reaction activity, providing a facile and mild approach for the development of high performing MoS2 and other two-dimensional lamellar materials. [ABSTRACT FROM AUTHOR]

A nitrogen doped bio-carbon catalyst with high specific surface area and a hierarchical interconnected porous structure was fabricated by an in situ gas-foaming strategy from sodium alginate and ammonium chloride. The optimized catalyst displays a fabulous ORR activity, providing a facile approach for the mass production of metal-free bio-carbon catalysts in fuel cells and metal–air batteries. [ABSTRACT FROM AUTHOR]

In order to develop efficient and earth-abundant catalysts for large-scale hydrogen evolution via water splitting, a Ni/Ni(OH)2 dual composition electrocatalyst was manufactured via a two-step electrodeposition procedure. The stepwise fabricated 3D hierarchical nanoarrays as well as the concurrent dual composition electrodeposition yielded a papillae-like hybrid crystal structure. The high electrochemically active surface area, defect-rich hybrid crystal structure, and synergistic effects of the dual composition provided an elevated catalytic performance. Only 53 mV overpotential was needed to deliver a current density of 10 mA cm−2 with a small Tafel slope of 54.5 mV dec−1 to catalyze the HER in alkaline media. Approximately 81% catalytic activity could be maintained after 20 h of continuous testing, demonstrating long-term stability. Our findings offer an efficient approach to design and fabricate efficient noble-metal-free alkaline HER electrocatalysts. [ABSTRACT FROM AUTHOR]

FexOy@FexOy/C nanoparticles with a soap-bubble-like shell have been synthesized, and the materials exhibit excellent Fenton catalytic performance. More importantly, FexOy@FexOy/C nanoparticles as catalysts and precursors could catalyze organic dye molecules to form iron oxide@organic dye polymer core–shell nanospheres. [ABSTRACT FROM AUTHOR]

Exploring non-noble and high-performance metal catalysts to replace platinum-based catalysts for the hydrogen evolution reaction (HER) via electrochemical water splitting significantly alleviates environmental pollution and the energy crisis. However, the synthetic approaches of such electrocatalysts are generally complex and challenging for large-scale production. Herein, a facile and green solid-state synthesis of Ni nanoparticles decorated with N-doped porous carbon is presented. These materials are derived from chitosan as carbon, nitrogen sources, and nickel acetate as a nickel source with NaCl as a template. The synthesis procedure is simple to scale up without an organic solvent. Benefiting from its porous structure, splendid conductivity, and the synergistic effect of Ni nanoparticles and holey N-doped carbon, the as-prepared Ni@CN exhibits superior HER performance in 1 M KOH with a low potential of 121 mV at 10 mA cm -2 . These findings indicate that the convenient and environmentally friendly synthesis approach provides a novel method for large-scale synthesis of HER electrocatalysts for industrial electrolytic water splitting applications.

Efficient non-noble metal bifunctional electrocatalysts can increase the conversion rate of electric energy in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a ball & sheet MoS 2 /Ni 3 S 2 composite with wide-layer-spacing and high 1T-rich MoS 2 is assembled on nickel foam (NF) via a two-step solvothermal method with polymeric sulfur (S-r-DIB) as the sulfur source. The obtained material serves as both the cathode and the anode toward overall water splitting in an alkaline electrolyte. The results proved that the interpenetration of MoS 2 /Ni 3 S 2 -p with a ball and sheet structure increased the material active surface area and exposed more catalytic active sites, which contributed to the penetration of solution and the transfer of charge/hydrion. Meanwhile, two different semiconductors of MoS 2 and Ni 3 S 2 along with the presence of ample active sulfur edge sites and few-layer, wide-layer-spacing structures of MoS 2 lead to an outstanding electrocatalytic activity. In particular, the electrodes of MoS 2 /Ni 3 S 2 -p only need a battery voltage of 1.55 V at 10 mA cm -2 . The bifunctional electrocatalyst MoS 2 /Ni 3 S 2 -p also shows excellent stability at large current densities during the electrochemical test.

Few-layer and 1T-rich MoS 2 is synthesized by a one-step solvothermal process using a rigid segment-containing polysulfide as a concomitant sulfur source and in situ intercalator. The prepared MoS 2 displays superior hydrogen evolution reaction activity, providing a facile and mild approach for the development of high performing MoS 2 and other two-dimensional lamellar materials.

The performance of a chemosensor is closely related to its structure. A new Schiff bass (DFSB) based on 4,5-diazafluorene units has been synthesized in this work. The interaction of DFSB with different metal ions has been studied using UV-vis absorption spectra and fluorescent spectra. The results show that DFSB is a highly selective and sensitive probe for Al 3+ ions over other commonly coexisting metal ions in ethanol. A very obvious fluorescence enhancement effect was observed, and a turn-on ratio over 1312-fold was triggered with the addition of 10 equiv. of Al 3+ ions. What is more, such fluorescent responses could be detected by the naked eye under a UV-lamp. The lowest detection limit for Al 3+ was determined as 3.7 × 10 -8 M. The complex solution (DFSB-Al 3+ ) exhibited reversibility with EDTA. These results may be caused by the unique molecular structure., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Functionalized magnetic adsorbents (FMAs) were synthesized by a facile and surfactant-free one-pot solvothermal approach, using iron(III) chloride hexahydrate as the precursor, ethylene glycol as the reducing agent, ammonium acetate, and EDTA-2Na as an electrostatic stabilization agent. The self-assembly process of the functionalized magnetic adsorbents has been investigated and a plausible mechanism is proposed. The resulting functionalized magnetic adsorbents have relatively high specific surface areas (71.6 m(2) g(-1)), excellent magnetic properties and rich functional groups (carboxyl groups, hydroxyl groups and hydrophobic groups). Meanwhile, the resulting FMAs were employed in the adsorption of dyes and heavy metal ions from aqueous solution. Herein, we took two types of typical pollutants, dyes (methylene blue (MB) and malachite green (MG)) and toxic heavy metal ions (Cr(VI) and Pb(II)) as examples of organic and inorganic pollutants in environmental water. The excellent intrinsic properties of the FMAs led to a stronger adsorption ability than a solid Fe3O4 adsorbent for MB, MG, Cr(VI) and Pb(II). Especially, the simultaneous adsorption of the functionalized flower-like magnetic adsorbents for MG and Pb(II) was also determined in a binary system. Finally, it was demonstrated that the resulting flower-like magnetic adsorbents are expected to be a good candidate as an adsorbent for water treatment.