Designing Highly Active S-g-C3N4/Te@NiS Ternary Nanocomposites for Antimicrobial Performance, Degradation of Organic Pollutants, and Their Kinetic Study

The current research is about the synthesis of pure nickel sulfide, a series of Te (0, 0.5, 1, 1.5, 2, and 3 wt.%)-doped NiS (Te@NiS) nanoparticles (NPs), and a series of S-g-C3N4 (10, 30, 50, 70, and 80 wt.%)/Te@NiS nanocomposites (NCs), fabricated through a hydrothermal route. XRD and FTIR spectroscopic techniques demonstrated the successful synthesis of NPs and NCs. SEM-EDX images confirmed the flakelike structure and elemental constituents of the fabricated materials. Tauc plots were drawn, to calculate the band gaps of the synthesized samples. Te doping resulted in a significant reduction in the band gap of the NiS NPs. The photocatalytic efficiency of the NPs and NCs was investigated against MB, under sunlight. The results obtained for the photocatalytic activity, showed that 1%Te@NiS nanoparticles have an excellent dye degradation capacity in sunlight. This was made even better by making a series of SGCN/1% Te@NiS nanocomposites with different amounts of S-g-C3N4. When compared to NiS, Te@NiS, SGCN, and 70%SGCN/1%Te@NiS, the 70%SGCN/1%Te@NiS NCs have excellent antifungal ability. The higher impact of SGCN/Te@NiS, may be due to its enhanced ability to disperse and interact with the membranes and intracellular proteins of fungi. The 70%SGCN/1%Te@NiS NCs showed excellent antibacterial and photocatalytic efficiency. Thus, the 70%SGCN/1%Te@NiS NCs might prove fruitful in antibacterial and photocatalytic applications.

Elucidating the Origin of Enhanced Photocatalytic Hydrogen Production on Tuned Cu7S4/CdS Heterostructures

Direct Z-scheme Cu 7 S 4 /CdS Janus photocatalysts are successfully prepared by cation exchange method. Extensive studies containing single-nanoparticle impact electrochemistry are performed and reveal that optimizing the Cu 7 S 4 /CdS ratio can decrease the accumulation of holes on valence band of CdS for inhibiting photocorrosion and promote the accumulation of electrons on the conduction band of Cu 7 S 4 for boosting the electron reducibility. With the optimized heterostructures, hydrogen evolution is remarkable promoted up to 21.62 mmol h -1 and quantum efficiency is up to 14.37 % using polylactic acid plastic waste as feedstock.

The lithium ions storage behavior of heteroatom-mediated echinus-like porous carbon spheres: From co-doping to multi-atom doping

This study proposed a facile method to prepare echinus-like porous carbon spheres (PCS) with different heteroatom doping for lithium ions battery (LIBs). A metal-organophosphine framework (MOPF) was synthesized by employing riboflavin sodium phosphate as an organic ligand to conjugate with metal ions and then carbonized at mild temperature, leading to the formation of heteroatom doped PCS (H-PCS). As a result, (N, P) co-, (N, P, Ni) tri-, (N, P, Co) tri- and (N, Ni, Co, P) tetra-doped PCS were obtained to examine the insight into lithium-ion storage behavior of H-PCS. It was found that the specific surface area, pore texture and structural defects of H-PCS were dependent on doping of heteroatoms as well as the charge transfer resistance and Li-ion diffusion coefficient. Significantly, the redox reaction potential during the charge/discharge could be mediated upon the doping. Thus, when evaluated as anode for LIBs, the (N, Ni, Co, P) tetra-doped PCS exhibited highly reversible capacity of 680 mAh g^-1 at 0.1 A g^-1, excellent rate capability (115.9 mAh g^-1 at 1.0 A g^-1) and superior cycling performance (399.6 mAh g^-1 at 0.1 A g^-1). Moreover, the cyclic voltammogram measurements demonstrated that the doping of metal atoms was favorable for improving the capacitive contribution of surface limited diffusion. Thus, this work highlighted the importance of HCP with defined doping which could be considered as one of the prominent candidates for high-performance LIBs' anode.

Reactive nanotemplates for synthesis of highly efficient electrocatalysts: beyond simple morphology transfer

Efficient electrocatalysts for energy conversion in general, and fuel cell operation and water electrolysis in particular, are pivotal for carbon-free hydrogen production. While the requirements of successful electrocatalysts include a high number density of catalytically active sites, high surface-to-volume ratio, inherently high catalytic activity, and robustness of the catalyst surface structure under harsh operating conditions, it is extremely difficult to synthesize nanocatalysts that could possess all these structural characteristics. Nanotemplate-mediated synthesis, namely, the coating or filling of a template with a desired material phase followed by the removal of the template, has captured the interest of researchers because of the ease of creating hollow-structured nanocatalysts with a high surface to volume ratio. Recent studies, however, have revealed that nanotemplates could be more than just passive supports because they greatly affect catalytic performance by creating an unusual synergy between the substrate and catalyst and by providing dopants to the actual catalyst phase owing to their reactive nature. In this review, we discuss the most notable recent advances in the nanotemplate-based synthesis of electrocatalysts as well as the unusual effects of nanotemplates on the performance of nanocatalysts. We also provide an outlook for this fledgling field so that future research efforts could be focused on the development of practically useful electrocatalysts that could shape the future of energy technologies.

Enzymeless biosensor based on β-NiS@rGO/Au nanocomposites for simultaneous detection of ascorbic acid, epinephrine and uric acid

In this study, marigold flower-like self-assembled β-NiS (nickel sulfide) nanosheets were grown on rGO (reduced graphene oxide) by a single-step hydrothermal process and then gold nanospheres (AuNS) were electrochemically deposited on the β-NiS@rGO nanostructures.

Co-Doped NiSe nanowires on nickel foam via a cation exchange approach as efficient electrocatalyst for enhanced oxygen evolution reaction

Co-Doped NiSe nanowires supported on nickel foam (NF) were successfully synthesized using NiSe NWs/NF as precursor template in a facile cation exchange approach.

Double metal ions synergistic effect in hierarchical multiple sulfide microflowers for enhanced supercapacitor performance

In this paper, the design, synthesis, and measurement of a new and hierarchically structured series of NixCo1-xS1.097 electroactive materials are reported. The materials were synthesized through an ion-exchange process using hierarchically structured CoS1.097 as precursors, and a strategy utilizing the synergistic effect of double metal ions was developed. Two complementary metal ions were used to enhance the performance of electrode materials. The specific capacitance of the electroactive materials was continuously improved by increasing the nickel ion content, and the electric conductivity was also enhanced when the cobalt ion was varied. Experimental results showed that the nickel ion content in NixCo1-xS1.097 could be adjusted from x = 0 to 0.48. Specifically, when x = 0.48, the composite exhibited a remarkable maximum specific capacitance approximately 5 times higher than that of the CoS1.097 precursors at a current density of 0.5 A g(-1). Furthermore, the specific capacitance of Ni0.48Co0.52S1.097 electrodes that were modified with reduced graphene oxide could reach to 1152 and 971 F g(-1) at current densities of 0.5 and 20 A g(-1) and showed remarkably higher electrochemical performance than the unmodified electrodes because of their enhanced electrical conductivity. Thus, the strategy utilizing the synergistic effect of double metal ions is an alternative technique to fabricate high-performance electrode materials for supercapacitors and lithium ion batteries.

Nanostructured metal sulfides for energy storage

Advanced electrodes with a high energy density at high power are urgently needed for high-performance energy storage devices, including lithium-ion batteries (LIBs) and supercapacitors (SCs), to fulfil the requirements of future electrochemical power sources for applications such as in hybrid electric/plug-in-hybrid (HEV/PHEV) vehicles. Metal sulfides with unique physical and chemical properties, as well as high specific capacity/capacitance, which are typically multiple times higher than that of the carbon/graphite-based materials, are currently studied as promising electrode materials. However, the implementation of these sulfide electrodes in practical applications is hindered by their inferior rate performance and cycling stability. Nanostructures offering the advantages of high surface-to-volume ratios, favourable transport properties, and high freedom for the volume change upon ion insertion/extraction and other reactions, present an opportunity to build next-generation LIBs and SCs. Thus, the development of novel concepts in material research to achieve new nanostructures paves the way for improved electrochemical performance. Herein, we summarize recent advances in nanostructured metal sulfides, such as iron sulfides, copper sulfides, cobalt sulfides, nickel sulfides, manganese sulfides, molybdenum sulfides, tin sulfides, with zero-, one-, two-, and three-dimensional morphologies for LIB and SC applications. In addition, the recently emerged concept of incorporating conductive matrices, especially graphene, with metal sulfide nanomaterials will also be highlighted. Finally, some remarks are made on the challenges and perspectives for the future development of metal sulfide-based LIB and SC devices.

Ag+ insertion into 3D hierarchical rose-like Cu(1.8)Se nanocrystals with tunable band gap and morphology genetic

In this study, novel hierarchical rose-like Cu1.8Se microspheres with a porous three-dimensional (3D) framework were successfully synthesized by using a one-pot in situ growth method at low temperature (60 °C). The Cu1.8Se microspheres covered the surface of the 3D porous framework. The formation mechanism was investigated in detail by adjusting the volume ratio of DMF and EDA, as the blend solvents, and the reaction time. Then, the chemical composition of the Cu1.8Se microspheres was altered by Ag(+) exchange without changing their morphology and structure. In this way, the binary Cu1.8Se was efficiently converted into the ternary CuAgSe. Notably, the band gap of materials was tuned continuously from 3.83 eV to 3.03 eV, and CuAgSe was produced continuously by adjusting the replacement time. This work provides a novel concept and a simple method that can serve as a good reference for improving the performance of tunable materials and the preparation of multielement alloy materials.