Two-step Hydrothermal Approach Research Articles

3D layered MgCo2O4@CoMoO4 porous nanomaterial arrays grown on nickel foams: Preparation and application as high-performance electrodes for supercapacitor

The advanced 3D layered porous MgCo2O4@CoMoO4 composite electrode (MCCo) was directly synthesized on a nickel foam substrate using a straightforward two-step hydrothermal approach. Among the various MCCo electrodes, the MCCo-7 h electrode demonstrated superior performance with a specific capacity of 2403 F g−1 due to its exceptional charge transfer internal resistance (Rs) and remarkable electrochemical characteristics. Notably, this performance surpassed that of MgCo2O4 (807 F g−1), MCCo-3 h (1224 F g−1), MCCo-5 h (1414 F g−1), MCCo-9 h (1936 F g−1), and CoMoO4-7 h electrode materials (442 F g−1). Furthermore, when MCCo-7 h was paired with activated carbon (AC) to construct a MCCo-7 h//AC device, it achieved an impressive energy density of 39 Wh kg−1 at a power density of 375 W kg−1, maintaining an impressive capacity retention of 83% even after 2000 cycles at a high current density of 5 A g−1. This groundbreaking work offers valuable insights and strategies for electrochemical energy storage and supercapacitors.

Development of anti-corrosive coating on AZ31 Mg alloy modified by MOF/LDH/PEO hybrids

The self-assembly of hybrid inorganic-organic materials on stationary platforms plays a critical role in improving their structural stability and wide usability. In this work, a novel two-step hydrothermal approach is proposed for synthesizing stable and advanced hybrid coatings on metal-oxide platforms through the surface modification of layered double hydroxide (LDH) films using novel metal-organic frameworks (MOFs). Initially, Mg-Al LDH nanocontainers, grown on a magnesium oxide layer produced through plasma electrolytic oxidation (PEO) of AZ31 Mg alloy substrate, were intercalated with cobalt via an oxidation route, providing the metallic coordination center for the MOF formation. In the subsequent step, a pioneering technique is introduced, utilizing tryptophan as the organic linker for the first time at a pH of 10. The self-assembly of cobalt- tryptophan complex, driven by the strong bonding between electrophilic sites of monomers and nucleophilic sites, facilitated the formation of a MOF network having a cloud-like structure on the surface of MgAl LDH's film. The resulting MOF-LDH encapsulation containers demonstrate exceptional electrochemical stability when exposed to a 3.5 wt.% NaCl solution, surpassing the performance of PEO and pure LDH coatings. This enhanced stability is attributed to the development of a dense top layer and a stable composition within the self-assembled MOF, effectively sealing flaws and preventing the infiltration of corrosive ions into the underlying metallic substrate. The formation mechanism of MOFs on LDH galleries is investigated using density functional theory calculations.

Activating the MnS0.5Se0.5 Microspheres as High-Performance Cathode Materials for Aqueous Zinc-Ion Batteries: Insight into In Situ Electrooxidation Behavior and Energy Storage Mechanisms.

Manganese-based materials are regarded as the most prospective cathode materials because of their high natural abundance, low toxicity, and high specific capacity. Nevertheless, the low conductivity, poor cycling performance, and controversial energy storage mechanisms hinder their practical application. Here, the MnS0.5Se0.5 microspheres are synthesized by a two-step hydrothermal approach and employed as cathode materials for aqueous zinc-ion batteries (AZIBs) for the first time. Interestingly, in-depth ex situ tests and electrochemical kinetic analyses reveal that MnS0.5Se0.5 is first irreversibly converted into low-crystallinity ZnMnO3 and MnOx by in situ electrooxidation (MnS0.5Se0.5-EOP) during the first charging process, and then a reversible co-insertion/extraction of H+/Zn2+ occurs in the as-obtained MnS0.5Se0.5-EOP electrode during the subsequent discharging and charging processes. Benefiting from the increased surface area, shortened ion transport path, and stable lamellar microsphere structure, the MnS0.5Se0.5-EOP electrodes deliver high reversible capacity (272.8mAhg-1 at 0.1Ag-1), excellent rate capability (91.8mAhg-1 at 2Ag-1), and satisfactory cyclic stability (82.1% capacity retention after 500 cycles at 1Ag-1). This study not only provides a powerful impetus for developing new types of manganese-based chalcogenides, but also puts forward a novel perspective for exploring the intrinsic mechanisms of in situ electrooxidation behavior.

Hydrothermal synthesis of ZnO Crystals: Diverse morphologies and characterization of the photocatalytic properties

Zinc oxide (ZnO) microstructures including the ZnO nanorods (R-ZnO), ZnO nanopillars (C-ZnO), and multistage microspheres composed of ZnO nanosheets (M-ZnO) have been synthesized using a two-step hydrothermal approach by adjusting the concentrations of the growth solution. Scanning Electron Microscopy (SEM) was employed to observe the surface morphology of the fabricated samples. X-ray diffraction (XRD) was utilized for the structure characterization, which the results reveal a hexagonal wurtzite ZnO structure in all three samples with different microstructures. X-ray Photoelectron Spectroscopy (XPS) was used to investigate their defects, indicating that the oxygen vacancy ratios were 34.3 %, 21.8 %, and 51.5 % respectively for R-ZnO, C-ZnO, and M-ZnO. The band gaps of R-ZnO, C-ZnO, and M-ZnO, determined through Ultraviolet–Visible Absorption Spectroscopy (UV–Vis), were found to be 3.35 eV, 3.6 eV, and 3.19 eV, respectively. Finally, the photocatalytic performances of the prepared ZnO samples were investigated under simulated sunlight irradiation by observing the degradation of methyl orange, which the M-ZnO samples obtained a superior photocatalytic efficiency of 79 %.

Highly Efficient SnIn4S8@ZnO Z-Scheme Heterojunction Photocatalyst for Methylene Blue Photodegradation.

Building heterojunctions is a promising strategy for the achievement of highly efficient photocatalysis. Herein, a novel SnIn4S8@ZnO Z-scheme heterostructure with a tight contact interface was successfully constructed using a convenient two-step hydrothermal approach. The phase composition, morphology, specific surface area, as well as photophysical characteristics of SnIn4S8@ZnO were investigated through a series of characterization methods, respectively. Methylene blue (MB) was chosen as the target contaminant for photocatalytic degradation. In addition, the degradation process was fitted with pseudo-first-order kinetics. The as-prepared SnIn4S8@ZnO heterojunctions displayed excellent photocatalytic activities toward MB degradation. The optimized sample (ZS800), in which the molar ratio of ZnO to SnIn4S8 was 800, displayed the highest photodegradation efficiency toward MB (91%) after 20 min. Furthermore, the apparent rate constant of MB photodegradation using ZS800 (0.121 min-1) was 2.2 times that using ZnO (0.054 min-1). The improvement in photocatalytic activity could be ascribed to the efficient spatial separation of photoinduced charge carriers through a Z-scheme heterojunction with an intimate contact interface. The results in this paper bring a novel insight into constructing excellent ZnO-based photocatalytic systems for wastewater purification.

Enhancing the activity of FeNi bimetallic electrocatalysts on overall water splitting by Nd2O3-induced FeNi lattice contraction

The development of high-efficiency and cost-effective bifunctional electrocatalysts for overall water splitting remains a formidable challenge. Herein, FeNi-Nd2O3 nanoparticles anchored on N-doped carbon nanotubes (FeNi-Nd2O3/NCN) are designed for highly effective overall water splitting via a facile two-step hydrothermal approach. The synthetic FeNi-Nd2O3 hetero-trimers (Fe 2p-Ni 2p-Nd 3d orbital coupling) on NCN achieve excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities with overpotentials of 270 and 120 mV at 10 mA cm−2 in 1 M KOH solution. Moreover, a small voltage of 1.52 V at 10 mA cm−2 is achieved when FeNi-Nd2O3/NCN is assessed as bifunctional catalyst for overall water splitting, which is superior to the typically integrated Pt/C and RuO2 counterparts (1.54 V at 10 mA cm−2). The related characterizations including X-ray absorption fine structure (XAFS) spectroscopy show that the remarkably improved activity is originated from Nd2O3-induced FeNi bimetallic lattice contraction. Furthermore, density functional theory (DFT) calculations indicate that the lattice contraction reduces binding energies of intermediates by downshifting the position of FeNi bimetallic d-band center relative to the Fermi level to optimize catalytic performance. Therefore, the Nd2O3-induced FeNi bimetallic lattice contraction may provide a new perspective for designing and synthesizing innovative catalytic systems.

Optimized Synthesis of Nanostructured Trimetallic Mn–V–Fe Selenides with Battery-Type Behavior for High-Performance Hybrid Supercapacitors

The design and synthesis of innovative materials with a specific architecture are necessary to advance the supercapacitor industry. Recently, transition metal selenides have been identified as an auspicious type of material for energy storage devices due to their enormous electronic conductivity and high theoretical capacitance. Consequently, mono- and diselenides have been extensively investigated. Trimetallic selenides, however, are infrequently reported, and their charge storage mechanism is still not fully understood. Herein, earth-abundant trimetallic Mn–V–Fe selenide (MVF-Se) is successfully fabricated via a two-step hydrothermal approach. The chemical composition, structure, and morphology of the as-synthesized material have been thoroughly characterized. The electrochemical tests revealed that the MVF-Se electrode possesses a high areal capacitance of 16,212.88 mF cm–2 at 1 mA cm–2 in the three-electrode configuration. In addition, the assembled asymmetric supercapacitor device by coupling MVF-Se and activated carbon as the positive and negative electrodes, respectively, demonstrates a desirable 0.56 mWh cm–2 energy density at a 1.0 mW cm–2 power density. After 17,000 charge/discharge cycles, the device exhibits robust cyclic stability with a 95% capacitance retention.

Catalytic binary oxides decorated zeolite as a remedy for As(III) polluted groundwater: Synergistic effects and mechanistic analysis

Inexpensively composites derived from industrial waste products are being extensively researched in water treatment, particularly in arsenic removal, to acquire safe water resources. Here, it is reported that a cheap and effective composite of marigold-flowered structured iron-manganese binary oxide decorated fly ash zeolite for efficient removal of As(III) from water, is fabricated using a two-step hydrothermal approach. Arsenite ions [As(III)] are highly harmful, soluble, mobile, and more challenging to eliminate from aqueous solution than arsenates [As(V)]. The synthesized composite is amorphous and has a high surface area (243.55 m2/g). The Z @ Fe3O4–MnO2 binary oxide composite showed a higher As(III) adsorption capacity than those of zeolite-free counterparts, their single-oxide components, and the pristine zeolite, in addition, to efficiently oxidative-adsorption of As(III) by Fe3O4–MnO2 system. The zeolite functioned as effective support that prevented aggregation of the oxide nanoparticles and contributed to the synergistic effects exhibited by Z @ Fe3O4–MnO2. The synthesized composite exhibited a maximum As(III)-removal capacity (80 mg/g) that was relatively higher than that competitive with that of most reported sorbents. Moreover, Z @ Fe3O4–MnO2 was able to eliminate 100% arsenic from natural groundwater, and the arsenic-loaded Z @ Fe3O4–MnO2 can be readily regenerated and repeatedly utilized for up to 4 cycles by maintaining WHO’s drinking water standard levels. The overall findings illuminate the effectiveness, feasibility, and reusability of the designed composite for water treatment.

Design and synthesis of Z-scheme LaFeO3/MoS2/graphene heterojunction with enhanced photocatalytic performance

Photocatalysis is an effective way to treat industrial wastewater. Therefore, the design of low-cost and high-activity photocatalysts is crucial for environmental remediation. Herein, a ternary Z-Scheme LaFeO3/MoS2/graphene nanocomposite photocatalyst was synthesized by a facile two-step hydrothermal approach and tested for the degradation of dye wastewater. To this end, graphene was employed as a substrate for loading LaFeO3 nanospheres and MoS2 nanosheets to act as an electron migration medium for Z-scheme heterojunction. The obtained LaFeO3/MoS2/graphene photocatalyst showed high efficiency and stable performance toward the degradation of methylene blue (MB), estimated to 16.5-fold higher than that of sole LaFeO3. The enhanced photocatalytic activity was mainly attributed to the synergistic effect between LaFeO3 and MoS2/graphene co-catalyst, leading to the expansion of the visible light absorption range and optimization of the redox potential. Most importantly, the closely contacted Z-scheme heterojunction interface between LaFeO3 and MoS2/graphene facilitated the separation and transport efficiency of photogenerated carriers, as well as prolonged the lifetime of photogenerated carriers. In sum, these results look promising for the future design of highly efficient LaFeO3-based photocatalysts with Z-scheme heterojunction structures.

Synthesis of hierarchically structured MnMoO4·H2O/Ni3S2 nanocomposites on Ni foam for high-performance asymmetric supercapacitors

In this work, hierarchically structured MnMoO4·H2O/Ni3S2 (MMONS) nanocomposites are grown in situ on Ni foam (NF) using an easy two-step hydrothermal approach. Benefiting from synergistic effect of the high specific capacity of MnMoO4·H2O, the high electrical conductivity of Ni3S2 and the hierarchical structure of the nanocomposite, the prepared MnMoO4·H2O/Ni3S2 electrode exhibits excellent electrochemical performance. Additionally, the hydrothermal time of Ni3S2 affecting on the MnMoO4·H2O/Ni3S2 electrode is investigated. Unlike the pristine MnMoO4·H2O and Ni3S2 electrodes, hierarchically structured MMONS electrode exhibits a high specific capacity of 1136 C g−1 at 1 A g−1. Moreover, it exhibits excellent cycle stability performance, retaining 77.4% capacitance after 10,000 charge–discharge cycling tests at 5 A g−1. An asymmetric supercapacitor (ASC) device exhibits an energy density of 55.87 Wh kg−1 at 695.97 W kg−1 and great cycle stability performance, maintaining 85.5% capacitance after 5000 cycling tests. This finding indicates that the hierarchically structured MnMoO4·H2O/Ni3S2 nanocomposites exhibit good electrochemical properties and high potential as electrode materials for supercapacitors.

Improvement of the wear and corrosion resistance of nitrocarburized H13 steel using hydrothermal-synthesized zeolite coating

A zeolite coating was synthesized on a nitrocarburized H13 steel substrate to improve its wear and corrosion resistance using a two-step hydrothermal synthesis approach. The wear test showed that compared with the nitrocarburized H13 substrate, the zeolite-coated sample offered significantly better wear resistance with slightly lower mean coefficient of friction (COF), narrower and shallower wear profiles, and an approximately half wear rate. During the wear process, the protruding corners and edges of the zeolite particles gradually abraded into smooth areas. The wear mechanism of the zeolite-coated H13 sample against the GCr15 grinding ball included the abrasive wear of zeolite particles, formation of a transfer layer, surface oxidation of the wear debris through plastic deformation, and peeling off of the local zeolite particles. Electrochemical and immersion tests showed that the synthesized zeolite coating significantly enhances the corrosion resistance of the steel.

Vanadium sulfide decorated graphitic carbon nitride nanocomposite for the enhanced photocatalytic activity towards organic pollutants

A simple, efficient and fast two-step hydrothermal approach was used to synthesize novel dandelion like vanadium sulfide (VS4) decorated graphitic carbon nitride (GCN) nanocomposite photocatalyst. Numerous characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy were used to investigate the physicochemical aspects such as crystallinity, morphology, optical properties and functional groups of the prepared pure GCN, pure VS4 and VS4/GCN nanocomposite. From the XRD analysis, the formation of VS4/GCN nanocomposite was confirmed with monoclinic structure. The optical characteristics were revealed by UV–vis Spectroscopy and bandgap energy values for pure GCN, pure VS4 and VS4/GCN nanocomposite were found to be 2.74 eV, 1.63 eV and 2.21 eV respectively. FTIR studies confirmed the functionalities in the nanocomposite formation. The dandelion like surface morphology of the prepared VS4 were confirmed by FE-SEM. Photocatalytic degradation process was carried out for the removal of organic dyes (Rhodamine B, methylene blue) from factitious wastewater under visible light irradiation. From the obtained results, a possible mechanism for the improvement of photocatalytic performance was discussed.

Mesoporous WS2/MoO3 Hybrids for High-Performance Trace Ammonia Detection.

Mesoporous WS2/MoO3 hybrids were synthesized by a facile two-step and additive-free hydrothermal approach and employed for high-performance trace ammonia gas (NH3) detection. Compared with single WS2 and MoO3 counterparts, WS2/MoO3 sensors exhibited an improvement in NH3-sensing performance at room temperature (22 ± 3 °C). Typically, the optimal WS2/MoO3 sensor showed a higher and quicker response of 31.58% within 57 s toward 3 ppm of NH3, which was 17.7- and 57.4-fold larger than that of pure MoO3 (1.78% within 251 s) and WS2 (0.55% within 153 s) ones. Meanwhile, good reversibility, sensitivity, and selectivity, reliable long-term stability, and the lowest detection limit of 9.0 ppb were achieved. These superior properties were probably ascribed to numerous heterojunctions favorable for additional carrier-concentration modulation via the synergetic effect between WS2 and MoO3 components and the large specific surface area beneficial for richer sorption sites and faster molecular transfer at room temperature. Such achievements also imply that the designed WS2/MoO3 heterostructure nanomaterials have the potential in achieving trace NH3 recognition catering for the requirements of high sensitivity and low power consumption in future gas sensors.

Synergistic Co–P bonding effect on hydrogen evolution reaction activity and supercapacitor applications of CoMoP material

Due to the synergistic effect between transition metals and hetero-atoms, transition metal-phosphide-based composites have been used as electrode materials for electrocatalytic hydrogen evolution reactions (HER) and supercapacitors, but their ideal performance has yet to be achieved. Herein, the binary transition metal phosphides, CoMoP and NiMoP, were grown on Ni-foam using a two-step hydrothermal approach and phosphorus deposition in a tube furnace. Both the CoMoP and NiMoP materials showed promising HER activity, displaying an overpotential of 137 mV and 144 mV @10 mA/cm2, respectively. The theoretical studies demonstrated that the ΔGH∗ on CoMoP (−0.28 eV) was closer to zero than on NiMoP (−0.34 eV), due to the synergistic Co–P bonding, making it more accessible for H-adsorption, thereby endowing HER. In addition, the CoMoP and NiMoP materials exhibited 3507 F/g and 930 F/g energy storage capacities, respectively. Moreover, both samples had close to 100% Coulombic efficiency and about 50% capacitance retention. Based on these findings, it looks like CoMoP could be good for both the HER and supercapacitor electrodes.

3D core-shell structured NiFe layered double hydroxide with NiCo2O4 as an efficient electrocatalysts for oxygen evolution reaction

In this work, a 3D core-shell NiFe-LDH/NiCo2O4/NF nanostructured composite with intimate interface have been successfully synthesized via a two-step hydrothermal approach. The core-shell composites demonstrate excellent electrocatalytic behavior due to its unique 3D core-shell microstructure and the optimized electron migration pathway. When NiFe-LDH anchors on the surface of NiCo2O4, the formation of Fe3+, Ni3+ and Co2+ in the composite induced by electrons migrate from Fe2+ and Ni2+ in the NiFe-LDH shell to Co3+ in the NiCo2O4 core can significantly promote charge transfer across interface and thereby boosting its oxygen evolution reaction (OER). In comparison to its single-component and hydroxide, the composite delivers a low overpotential of 363 mV for 50 mA cm−2, a small Tafel slope of 53.03 mV·dec−1, and satisfactory long-term stability, which makes it comparable to commercial IrO2 catalysts. These results show on how 3D core-shell architecture and valence states of metal oxides influence on OER performance in NiFe-LDH/NiCo2O4 electrocatalysts and provide new insights for regulating LDH-based electrocatalysts.

Construction of NiCoZnS materials with controllable morphology for high-performance supercapacitors

A facile two-step hydrothermal approach with post-sulfurization treatment was put forward to construct the mixed transition metal sulfide (NiCoZnS) with a high electrochemical performance. The different morphologies of NiCoZnS materials were successfully fabricated by adjusted the Ni/Co molar ratio of the NiCoZn(OH)F precursor. Moreover, the in situ phase transformation from the NiCoZn(OH)F phase to Zn0.76Co0.24S and NiCo2S4 phases and lattice defects via the S2− ion-exchange were determined by x-ray diffractometer, transmission electron microscopy and x-ray photoelectron spectroscopy techniques, which improved electric conductivity and interfacial active sites of the NiCoZnS, and so promoted the reaction kinetics. Significantly, the urchin-like NiCoZnS1/1 prepared at the Ni/Co molar ratio of 1.0 exhibited promising electrochemical performances with high capacitance and excellent cycling stability. Furthermore, the asymmetric device (NiCoZnS//AC) using NiCoZnS1/1 as the positive electrode had excellent supercapacitor performances with an energy density of 57.8 Wh·kg–1 at a power density of 750 W·kg–1 as well as a long cycle life (79.2% capacity retention after 10 000 cycles), indicating the potential application in high-performance supercapacitors.

Interface charge density modulation of a lamellar-like spatially separated Ni9S8 nanosheet/Nb2O5 nanobelt heterostructure catalyst coupled with nitrogen and metal (M = Co, Fe, or Cu) atoms to accelerate acidic and alkaline hydrogen evolution reactions

A first report of the rational design of novel heterostructure of M−N−Ni 9 S 8 /Nb 2 O 5 catalysts ( M = Co, Fe, or Cu) via facile two-step hydrothermal approach. The synergy of spatially separated nanosheets of Ni 9 S 8 /Nb 2 O 5 nanobelts with N and M (Co, Fe, or Cu) atoms were examined in depth. This work highlights a rational heterostructure design strategy and demonstrates the importance of optimizing the HER kinetics. • Novel M−N−Ni 9 S 8 /Nb 2 O 5 ( M = Co, Fe, or Cu) heterostructure was made by a facile method. • Synergy of spatially separated nanosheet of Ni 9 S 8 /Nb 2 O 5 nanobelt with N and metal atoms was examined in depth. • Interface engineering of M−N−Ni 9 S 8 /Nb 2 O 5 ( M = Co, Fe, or Cu) heterostructures facilitates the acidic/alkaline HER activity. • Enhancement in HER kinetics of heterostructures was examined in detail by DFT predictions. The creation of heterostructures based on non-precious metals with platinum-like hydrogen evolution reaction (HER) performance remains a challenge for hydrogen fuel technologies. Motivated by the fascinating properties of heterostructures, we establish here an effective approach to fabricate the heterostructured M−N−Ni 9 S 8 /Nb 2 O 5 ( M = Co, Fe, or Cu) catalysts using spatially separated Ni 9 S 8 nanosheet/Nb 2 O 5 nanobelts that are coupled with nitrogen (N) and metal atoms. Due to its improved intrinsic activity, interface-rich structure, abundant active sites, and large surface area the Co−N−Ni 9 S 8 /Nb 2 O 5 heterostructure achieved a low acidic HER overpotential of −171 mV at −10 mA cm −2 , thereby performing better than existing heterostructures. Moreover, for the alkaline HER, the Cu−N−Ni 9 S 8 /Nb 2 O 5 heterostructure required a low overpotential of −109 mV at −10 mA cm −2 , which is close to the performance of Pt/C catalyst. Density functional theory (DFT) predictions indicate that the local charge distribution and electronic properties at the heterointerface of Ni 9 S 8 /Nb 2 O 5 can be significantly modulated by co-doping of metals with N atoms, resulting in optimal adsorption energy and reduced water dissociation barrier; thereby accelerating the acidic and alkaline HER activity. This work, therefore, provides a new design principle to create advanced heterostructured catalysts.

Construction of coral rod-like MoS2@HA nanowires hybrids for highly effective green antisepsis

Antibacterial materials have been rapidly emerging as a primary component in the mitigation of bacterial pathogens, and green functional materials play a vital role in the antibacterial field. In this study, biocompatible hydroxyapatite nanowires (HANW) was used as a carrier, a coral rod-like nanowires hybrid of MoS2 and HANW (CR-MoS2@HANW) was synthesized via a facile two-step hydrothermal approach. After being characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmet-Teller (BET) and thermogravimetric (TG) analysis, the antibacterial activity and environmental compatibility were assessed. It was found that MoS2 nanosheets were in-situ assembled onto surface of HA nanowires, and the obtained nanohybrid exhibited excellent stability. CR-MoS2@HANW endowed a desirable long-term antibacterial activity against both gram-negative E. coli and gram-positive S. aureus. It was sufficient to inhibit the growth of bacteria within 72 h, and nanohybrids effectively promoted the growth of plants. In summary, the combination of MoS2 and HANW created a novel eco-friendly nanohybrids that could be applied as a promising multi-functional green antisepsis. And the CR-MoS2@HANW possessed enormous potential for biomedical applications.

Synthesis of CaIn2S4/TiO2 heterostructures for enhanced UV–visible light photocatalytic activity

Semiconductor heterostructures are regarded as an efficient way to improve the photocatalytic activity. Herein, novel Z-scheme CaIn2S4 (CIS)/TiO2 heterostructures photocatalysts were synthesized by a simple two-step hydrothermal approach. Compared with single phase nanostructures of TiO2 and CIS, the CIS/TiO2-0.05 g nanocomposites exhibited efficient and stable photocatalytic activity, with 97% of methyl orange (MO) decomposed within 30 min under UV–visible light irradiation. In addition to increased broad light absorption, the outstanding photocatalytic performance is mainly attributed to intimate contact and matched energy band positions between CIS and TiO2, which efficiently produce more active electrons and holes, reduce the photogenerated electron-hole recombination, and boost photoinduced charge carrier transfer. The possible Z-scheme mechanism for the photocatalytic reaction in the system was reasonably proposed. This work would arouse an increasing interest in designing more Z-scheme heterojunction photocatalysts with high efficiency for the application of photodegradation.

NiCo2S4/nitrogen and sulfur dual-doped three-dimensional holey-reduced graphene oxide composite architectures as high-rate battery-type cathode materials for hybrid supercapacitors

Battery-type electrode materials have recently been considered as a new class of high-capacity cathode materials for construction of hybrid supercapacitors, however, their low electrochemical kinetics prevent the practical application. Here, the NiCo2S4/nitrogen and sulfur dual-doped three-dimensional (3D) holey-reduced graphene oxide (NiCo2S4/N, S-HRGO) composite architectures were synthesized via a two-step hydrothermal approach. Thanks to the introduction of 3D interconnected and highly conductive holey-reduced graphene oxide with mesopore-rich structure providing fast electron/ion transport, the as-resulted NiCo2S4/N, S-HRGO composite achieves enhanced supercapacitive performances, especially exceptional rate capability compared to the pure NiCo2S4 and NiCo2S4/nitrogen and sulfur dual-doped reduced graphene oxide (NiCo2S4/N, S-RGO). The NiCo2S4/N, S-HRGO composite shows a specific capacity of 184.2 mAh g−1 at 1 A g−1, and still maintains a high specific capacity of 119.5 mAh g−1 even at 50 A g−1. The excellent rate capability of the composite can be illustrated by in-depth kinetic analysis based on the calculated diffusion coefficient and charge contribution ratio. Furthermore, a hybrid supercapacitor utilizing NiCo2S4/N, S-HRGO and N, S, P tri-doped holey-reduced graphene oxide (N, S, P-HHGO) respectively as the cathode and anode is further constructed, showing a satisfactory energy density (35.4 Wh kg−1), high power density (15.0 kW kg−1) and good cycle durability.