A direct-write method for preparing a bimetal sulfide/graphene composite as a free-standing electrode for high-performance microsupercapacitors

It is a great challenge to ideally integrate graphene with its unique two-dimensional (2D) and porous structure into the pseudocapacitive materials. In this paper, a simple technique, i.e. direct-laser-writing (DLW), was developed to fabricate microsupercapacitors (MSCs) with excellent electrochemical performance, marked as Ni–Co–S/laser induced graphene (LIG) that exhibit a high areal specific capacitance of 680 mF cm⁻² at the current density of 1 mA cm⁻². A symmetric MSC device was assembled using Ni–Co–S/LIG as a positive electrode and active carbon (AC) as the negative electrode, and exhibited a high areal energy density of 56.9 μW h cm⁻² at the power density of 800 μW cm⁻², and excellent cycling stability maintaining 89.6% of the areal specific capacitance after 8000 cycles. The synergistic effect of bimetallic Ni–Co–S and the LIG with the 2D structure results in the excellent electrochemical performance. This work demonstrates a method to integrate Ni–Co–S pseudocapacitive materials into porous graphene with a direct-laser-writing technique. The produced integrated materials possess high energy density that can be used in MSCs.

This work demonstrates a method to integrate Ni–Co–S pseudocapacitive materials into the porous graphene producing from direct-laser-writing technique.     

Formation of nickel–cobalt sulphide@graphene composites with enhanced electrochemical capacitive properties

Here, nickel–cobalt sulphide particles embedded in graphene layers (porous Ni–Co–S@G), were successfully prepared by one-step annealing of metallocene/metal–organic framework (MOF) hybrids involving simultaneous carbonization and sulfidation. Benefiting from the porous structure, highly conductive graphene layers and large loading of super-capacitive Ni–Co–S, the obtained Ni–Co–S@G composites exhibited excellent electrochemical performance with a specific capacitance of 1463 F g⁻¹ at a current density of 1 A g⁻¹. A flexible solid-state asymmetric supercapacitor (ASC), assembled with Ni–Co–S@G and active carbon, demonstrated a high energy density of 51.0 W h kg⁻¹ at a power density of 650.3 W kg⁻¹. It is noteworthy that the ASC offered robust flexibility and excellent performance that was maintained when the devices were bent at various angles. The results indicate that the as-prepared materials could potentially be applied in high-performance electrochemical capacitors.

Ni–Co–S@graphene composites, derived from a metallocene/MOF precursor, presents high energy density and excellent cycling stability.     

Hierarchical Ni–Co–Mn hydroxide hollow architectures as high-performance electrodes for electrochemical energy storage

In this study, hierarchical Ni–Co–Mn hydroxide hollow architectures were successfully achieved via an etching process. We first performed the synthesis of NiCoMn-glycerate solid spheres via a solvothermal route, and then NiCoMn-glycerate as the template was etched to convert into hierarchical Ni–Co–Mn hydroxide hollow architectures in the mixed solvents of water and 1-methyl-2-pyrrolidone. Hollow architectures and high surface area enabled Ni–Co–Mn hydroxide to manifest a specific capacitance of 1626 F g⁻¹ at 3.0 A g⁻¹, and it remained as large as 1380 F g⁻¹ even at 3.0 A g⁻¹. The Ni–Co–Mn hydroxide electrodes also displayed notable cycle performance with a decline of 1.6% over 5000 cycles at 12 A g⁻¹. Moreover, an asymmetric supercapacitor assembled with this electrode exhibited an energy density of 44.4 W h kg⁻¹ at 1650 W kg⁻¹ and 28.5 W h kg⁻¹ at 12 374 W kg⁻¹. These attractive results demonstrate that hierarchical Ni–Co–Mn hydroxide hollow architectures have broad application prospects in supercapacitors.

An effective etching method is developed for the synthesis of hierarchical Ni–Co–Mn hydroxide hollow architectures, which exhibit high performance in electrochemical energy storage.     

Gamma radiation as a green method to enhance the dielectric behaviour,magnetization, antibacterial activity and dye removal capacity of Co–Fe LDH nanosheets

Nowadays, improving the physico-chemical properties of nanomaterials to enhance their performance towards various applications is urgent. Accordingly, gamma irradiation (GI) has evolved and attracted wide attention as a promising green technique to meet this need. In the current study, a Co–Fe LDH was used as a model 2D nanomaterial and was irradiated by GI (dose = 100 kGy). The sample was characterized via XRD, FTIR, FESEM, HRTEM, hydrodynamic size, zeta potential, and BET surface area measurements. The results showed that after irradiation, the surface area of the sample increased from 83 to 89 m² g⁻¹. Moreover, irradiation increased its dielectric constant, dielectric loss and AC conductivity. In addition, the sample showed superparamagnetic behavior, where its saturation magnetization increased from 1.28 to 52.04 emu g⁻¹ after irradiation. Furthermore, the adsorption capacity of the irradiated LDH towards malachite green (MG) and methylene blue (MB) as model wastewater pollutants was also studied. The exposure of LDH to GI enhanced its adsorption capacity for MG from 44.73 to 54.43 mg g⁻¹. The Langmuir–Freundlich, Sips, and Baudu models were well suited for both MG and MB adsorption among the six fitted isotherm models. The pseudo-first and second order models fit the adsorption kinetics better than the intraparticle diffusion model for both dyes. The interaction of MB and MG with the LDH surface was further investigated in dry and aqueous solution using Grand canonical Monte Carlo and molecular dynamics simulations. These two techniques provided insight into the adsorption mechanism, which is vital to understand the adsorption process by the LDH nanosheets and their possible use in practical applications. Moreover, the Co–Fe LDH showed good antibacterial activity against both Gram-positive and Gram-negative bacteria strains. Furthermore, due to its magnetic property, the Co–Fe LDH could be simply recovered from water by magnetic separation at a low magnetic field after the adsorption process.

Nowadays, improving the physico-chemical properties of nanomaterials to enhance their performance towards various applications is urgent.     

Facile hydrothermal synthesis of ternary Ni–Co–Se/carbon nanotube nanocomposites as advanced electrodes for lithium storage

Ternary Ni–Co–Se/carbon nanotube nanocomposites have been successfully prepared via a one-step hydrothermal strategy. When used as electrode materials for lithium-ion batteries, the Ni–Co–Se/CNT composite exhibits good lithium storage performances including excellent cycling stability and outstanding specific capacity, good cycling stability, and high initial coulombic efficiency. A high specific capacity of 687.8 mA h g⁻¹ after 100 charge–discharge cycles at a current density of 0.5 A g⁻¹ with high cycling stability is achieved. The excellent battery performance of Ni–Co–Se/CNT should be attributed to the synergistic effect of Ni and Co ions and the formed network structure.

A Ni–Co–Se/CNT composite exhibits outstanding Li-ion storage performance with respect to high reversible Li-storage capacity, high cyclability and high rate performance.     

Bimetallic nickel/manganese phosphate–carbon nanofiber electrocatalyst for the oxidation of formaldehyde in alkaline medium

The development of earth-abundant transition metal-based catalysts, supported by a conductive carbonaceous matrix, has received great attention in the field of conversion of formaldehyde derivatives into toxic-free species. Herein, we report a comprehensive investigation of bimetallic electrocatalyst activity towards the electrooxidation of formaldehyde. The bimetallic phosphate catalyst is prepared by co-precipitation of Ni and Mn phosphate precursors using a simple reflux approach. Then the bimetallic catalyst is produced by mixing the Ni/Mn with carbon fibres (CNFs). The structural properties and crystallinity of the catalyst were investigated by using several techniques, such as scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and Brunauer Emmett−Teller theory. The system performance was studied under potentiostatic conditions. Some theoretical thermodynamic and kinetic models were applied to assess the system performance. Accordingly, key electrochemical parameters, including surface coverage (Γ) of active species, charge transfer rate (k_s), diffusion coefficient of the formaldehyde (D), and catalytic rate constant (k_cat) were calculated at Γ = 1.690 × 10⁻⁴ mmol cm⁻², k_s = 1.0800 s⁻¹, D = 1.185 × 10⁻³ cm² s⁻¹ and k_cat = 1.08 × 10⁵ cm³ mol⁻¹ s⁻¹. These findings demonstrate the intrinsic electrocatalytic activity of formaldehyde electrooxidation on nickel/manganese phosphate- CNFs in alkaline medium.

The catalytic performance of bimetallic Ni/Mn phosphate–carbon nanofiber composite catalyst is better than mono metallic catalysts toward electrooxidation of formaldehyde.     

Efficient removal of chromate ions from aqueous solution using a highly cost-effective ferric coordinated [3-(2-aminoethylamino)propyl]trimethoxysilane–MCM-41 adsorbent

The present investigation involves synthesis and characterization of MCM-41–AEAPTMS–Fe(iii)Cl using coordinated Fe(iii) on MCM-41–AEAPTMS for efficient removal of hazardous Cr(vi) ions from aqueous solution. The adsorbent MCM-41–AEAPTMS–Fe(iii)Cl was characterized using small-angle X-ray diffraction (SAX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier-transform infrared (FT-IR) and Brunauer–Emmett–Teller (BET) surface analyzer techniques. The BET surface area was found to be 87.598 m² g⁻¹. The MCM-41–AEAPTMS–Fe(iii)Cl effectively adsorbs Cr(vi) with an adsorption capacity acquiring the maximum value of 84.9 mg g⁻¹ at pH 3 at 298 K. The data followed pseudo-second-order kinetics and obeyed the Langmuir isotherm model. The thermodynamic data proved the exothermic and spontaneous nature of Cr(vi) ion adsorption on MCM-41–AEAPTMS–Fe(iii). Further, the higher value of ΔH° (−64.339 kJ mol⁻¹) indicated that the adsorption was chemisorption in nature.

The present investigation involves synthesis and characterization of MCM-41–AEAPTMS–Fe(iii)Cl using coordinated Fe(iii) on MCM-41–AEAPTMS for efficient removal of hazardous Cr(vi) ions from aqueous solution.     

Facile preparation of porous sheet–sheet hierarchical nanostructure NiO/Ni–Co–Mn–Ox with enhanced specific capacity and cycling stability for high performance supercapacitors

NiO, Ni–Co–Mn–O_x and NiO/Ni–Co–Mn–O_x on nickel foam substrates were prepared via a chemical bath deposition–calcination. The thermodynamic behavior was observed by TG/DTA. The chemical structure and composition, phase structure and microstructures were tested by XPS, XRD, FE-SEM and TEM. The electrochemical performance was measured by CV, GCD and EIS. The mechanism for formation and enhancing electrochemical performance is also discussed. Firstly, the precursors such as NiOOH, CoOOH and MnOOH grow on nickel foam substrates from a homogeneous mixed solution via chemical bath deposition. Thereafter, these precursors are calcined and decomposed into NiO, Co₃O₄ and MnO₂ respectively under different temperatures in a muffle furnace. Notably, NiO/Ni–Co–Mn–O_x on nickel foam substrates reveals a high specific capacity with 1023.50 C g⁻¹ at 1 A g⁻¹ and an excellent capacitance retention with 103.94% at 5 A g⁻¹ after 3000 cycles in 2 M KOH, its outstanding electrochemical performance and cycling stability are mainly attributed to a porous sheet–sheet hierarchical nanostructure and synergistic effects of pseudo-capacitive materials and excellent redox reversibility. Therefore, this research offers a facile synthesis route to transition metal oxides for high performance supercapacitors.

NiO, Ni–Co–Mn–O_x and NiO/Ni–Co–Mn–O_x on nickel foam substrates were prepared via a chemical bath deposition–calcination.     

In situ hydrothermal synthesis of nickel cobalt sulfide nanoparticles embedded on nitrogen and sulfur dual doped graphene for a high performance supercapacitor electrode

Nickel cobalt sulfide nanoparticles (NCS) embedded onto a nitrogen and sulfur dual doped graphene (NS-G) surface are successfully synthesized via a two-step facile hydrothermal process. The electrical double-layer capacitor of NS-G acts as a supporting host for the growth of pseudocapacitance NCS nanoparticles, thus enhancing the synergistic electrochemical performance. The specific capacitance values of 1420.2 F g⁻¹ at 10 mV s⁻¹ and 630.6 F g⁻¹ at 1 A g⁻¹ are achieved with an impressive capability rate of 76.6% preservation at 10 A g⁻¹. Furthermore, the integrating NiCo₂S₄ nanoparticles embedding onto the NS-G surface also present a surprising improvement in the cycle performance, maintaining 110% retention after 10 000 cycles. Owing to the unique morphology an impressive energy density of 19.35 W h kg⁻¹ at a power density of 235.0 W kg⁻¹ suggests its potential application in high-performance supercapacitors.

Newly developed in situ hydrothermal synthesis governs morphology of Ni–Co–S embedded on N–S doped graphene thus providing exceptional capacitive behavior.     

The effect of 3D carbon nanoadditives on lithium hydroxide monohydrate based composite materials for highly efficient low temperature thermochemical heat storage

Lithium hydroxide monohydrate based thermochemical heat storage materials were modified with in situ formed 3D-nickel-carbon nanotubes (Ni-CNTs). The nanoscale (5–15 nm) LiOH·H₂O particles were well dispersed in the composite formed with Ni-CNTs. These composite materials exhibited improved heat storage capacity, thermal conductivity, and hydration rate owing to hydrogen bonding between H₂O and hydrophilic groups on the surface of Ni-CNTs, as concluded from combined results of in situ DRIFT spectroscopy and heat storage performance test. The introduction of 3D-carbon nanomaterials leads to a considerable decrease in the activation energy for the thermochemical reaction process. This phenomenon is probably due to Ni-CNTs providing an efficient hydrophilic reaction interface and exhibiting a surface effect on the hydration reaction. Among the thermochemical materials, Ni-CNTs–LiOH·H₂O-1 showed the lowest activation energy (23.3 kJ mol⁻¹), the highest thermal conductivity (3.78 W m⁻¹ K⁻¹) and the highest heat storage density (3935 kJ kg⁻¹), which is 5.9 times higher than that of pure lithium hydroxide after the same hydration time. The heat storage density and the thermal conductivity of Ni-CNTs–LiOH·H₂O are much higher than 1D MWCNTs and 2D graphene oxide modified LiOH·H₂O. The selection of 3D carbon nanoadditives that formed part of the chemical heat storage materials is a very efficient way to enhance comprehensive performance of heat storage activity components.

3D carbon modified LiOH·H₂O particles were well dispersed into nanoparticles (5–15 nm) and tested using in situ DRIFT spectroscopy.     

The promoted catalytic hydrogenation performance of bimetallic Ni–Co–B noncrystalline alloy nanotubes

A noncrystalline Ni–B alloy in the shape of nanotubes has demonstrated its superior catalytic performance for some hydrogenation reactions. Remarkable synergistic effects have been observed in many reactions when bimetallic catalysts were used; however, bimetallic noncrystalline alloy nanotubes are far less investigated. Here, we report a simple acetone-assisted lamellar liquid crystal approach for synthesizing a series of bimetallic Ni–Co–B nanotubes and investigate their catalytic performances. The dilution effect of acetone on liquid crystals was characterized by small-angle X-ray diffraction (SAXRD) and scanning electron microscopy (SEM). The Ni/Co molar ratio of the catalyst was varied to study the composition, porous structure, electronic interaction, and catalytic efficiency. In the liquid-phase hydrogenation of p-chloronitrobenzene, the as-prepared noncrystalline alloy Ni–Co–B nanotubes exhibited higher catalytic activity and increased stability as compared to Ni–B and Co–B alloy nanotubes due to electronic interactions between the nickel and cobalt. The excellent hydrogenation performance of the Ni–Co–B nanotubes was attributed to their high specific surface area and the characteristic confinement effects, compared with Ni–Co–B nanoparticles.

Ni–Co–B noncrystalline alloy nanotubes exhibited higher catalytic activity and better stability due to the synergistic interactions between nickel and cobalt.     

Co,N-co-doped graphene sheet as a sulfur host for high-performance lithium–sulfur batteries

To improve the performance of lithium-sulfur (Li–S) batteries, herein, based on the idea of designing a material that can adsorb polysulfides and improve the reaction kinetics, a Co,N-co-doped graphene composite (Co–N–G) was prepared. According to the characterization of Co–N–G, there was a homogeneous and dispersed distribution of N and Co active sites embedded in the Co–N–G sample. The 2D sheet-like microstructure and Co, N with a strong binding energy provided significant physical and chemical adsorption functions, which are conducive to the bonding S and suppression of LiPSs. Moreover, the dispersed Co and N as catalysts promoted the reaction kinetics in Li–S batteries via the reutilization of LiPSs and reduced the electrochemical resistance. Thus, the discharge specific capacity in the first cycle for the Co–N–G/S battery reached 1255.7 mA h g⁻¹ at 0.2C. After 100 cycles, it could still reach 803.0 mA h g⁻¹, with a retention rate of about 64%. This phenomenon proves that this type of Co–N–G composite with Co and N catalysts plays an effective role in improving the performance of batteries and can be further studied in Li–S batteries.

Design of two-dimensional graphene with dispersed Co–N catalysts as a multifunctional S holding material in Li–S batteries to improve the retention of LiPSs and accelerate the reaction kinetics.     

The structural transition of bimetallic Ag–Au from core/shell to alloy and SERS application

It is well-known that Ag–Au bimetallic nanoplates have attracted significant research interest due to their unique plasmonic properties and surface-enhanced Raman scattering (SERS). In recent years, there have been many studies on the fabrication of bimetallic nanostructures. However, controlling the shape, size, and structure of bimetallic nanostructures still has many challenges. In this work, we present the results of the synthesis of silver nanoplates (Ag NPls), and Ag–Au bimetallic core/shell and alloy nanostructures, using seed-mediated growth under green LED excitation and a gold salt (HAuCl₄) as a precursor of gold. The results show that the optical properties and crystal structure strongly depend on the amount of added gold salt. Interestingly, when the amount of gold(x) in the sample was less than 0.6 μmol (x < 0.6 μmol), the structural nature of Ag–Au was core/shell, in contrast x > 0.6 μmol gave the alloy structure. The morphology of the obtained nanostructures was investigated using the field emission scanning electron microscopy (FESEM) technique. The UV–Vis extinction spectra of Ag–Au nanostructures showed localized surface plasmon resonance (LSPR) bands in the spectral range of 402–627 nm which changed from two peaks to one peak as the amount of gold increased. Ag–Au core/shell and alloy nanostructures were utilized as surface enhanced Raman scattering (SERS) substrates to detect methylene blue (MB) (10⁻⁷ M concentration). Our experimental observations indicated that the highest enhancement factor (EF) of about 1.2 × 10⁷ was obtained with Ag–Au alloy. Our detailed investigations revealed that the Ag–Au alloy exhibited significant EF compared to pure metal Ag and Ag–Au core/shell nanostructures. Moreover, the analysis of the data revealed a linear dependence between the logarithm of concentration (log C) and the logarithm of SERS signal intensity (log I) in the range of 10⁻⁷–10⁻⁴ M with a correlation coefficient (R²) of 0.994. This research helps us understand better the SERS mechanism and the application of Raman spectroscopy on a bimetallic surface.

It is well-known that Ag–Au bimetallic nanoplates have attracted significant research interest due to their unique plasmonic properties and surface-enhanced Raman scattering (SERS).     

A novel BMSN (biologically synthesized mesoporous silica nanoparticles) material: synthesis using a bacteria-mediated biosurfactant and characterization

Mesoporous materials (MMs) have recently been applied as advanced nanomaterials in different fields (separation, catalysis, adsorption etc.). Synthesis of MMs by chemical surfactants is not ecofriendly. This study focused on the biological synthesis of a MM by sol–gel method, using a Bacillus subtilis BBK006-mediated surfactant (template) and a precursor (TEOS). The biologically synthesized mesoporous silica nanoparticles (BMSN) were formed at calcination temperatures of 450–600 °C. The BMSN comprise Si and O elements with specific weights of 56.09% and 42.13% respectively, where the atomic% was detected to be 41.79% and 55.10%, respectively. The phase identity of the synthesized particles (61–300 nm uniform spherical shape; surface area: 8.2616 m² g⁻¹; pore diameter at 550 °C: 14.8516 nm) was confirmed with wide-angle XRD (10°–81°). A typical type IV isotherm was exhibited (BET curves) following IUPAC nomenclature and confirmed the mesoporous nature. The green-synthesized biosurfactant-mediated BMSN is an environmentally promising material to apply in biomedical science (e.g., antimicrobial activity, drug delivery, CMC, anticancer activity) and oil spill management.

Synthesis of a novel BMSN material using bacteria-mediated biosurfactant and their characterization.     

Dinuclear molecular magnets with unblocked magnetic connectivity: magnetocaloric effect

A detailed study of the magnetocaloric effect in two isostructural bimetallic compounds {[M^II(H₂O)₂]₂[Nb^IV(CN)₈]·4H₂O}_n (M = Mn, Fe) is presented. The substances show sharp phase transitions to the long-range magnetically ordered state with ferromagnetic coupling between M and Nb sublattices in the case of the Fe-based sample (FeNb, T_c = 43 K) and antiferromagnetic coupling for the Mn-based sample (MnNb, T_c = 50 K). The magnetic entropy change was found to reach 5.07 J mol⁻¹ K⁻¹ (9.09 J kg⁻¹ K⁻¹) for MnNb and 4.82 J mol⁻¹ K⁻¹ (8.65 J kg⁻¹ K⁻¹) for FeNb under the applied magnetic field change of 5 T. Isothermal entropy changes corresponding to different field changes are demonstrated to collapse on a single master curve, which confirms the magnetic transitions in FeNb and MnNb to be of the second order. The results obtained for FeNb and MnNb are discussed in the context of MCE tunability by un/blocking of magnetic connectivity through dis/reconnection of spatially extended ligands.

The study of magnetocaloric effect in two related bimetallic cyanide-bridged molecular magnets: {[M (H₂O)₂]₂[Nb (CN)₈]·4H₂O}_n (M = Mn, Fe) is presented.     

Boosting the singlet oxygen production from H2O2 activation with highly dispersed Co–N-graphene for pollutant removal

Singlet oxygen (¹O₂) is a promising reactive species for the selective degradation of organic pollutants. However, it is difficult to generate ¹O₂ from H₂O₂ activation with high efficiency and selectivity. In this work, a graphene-supported highly dispersed cobalt catalyst with abundant Co–N_x active sites (Co–N-graphene) was synthesized for activating H₂O₂. The Co–N-graphene catalyzed H₂O₂ reaction system selectively catalyzed ¹O₂ production associated with the superoxide radical (O₂˙⁻) as the critical intermediate, as proven by scavenger experiments, electron spin resonance (ESR) spin trapping and a kinetic solvent isotope effect study. This resulted in excellent degradation efficiency towards the model organic pollutant methylene blue (MB), with an outstanding pseudo-first-order kinetic rate constant of 0.432 min⁻¹ (g L_catalyst⁻¹)⁻¹ under optimal reaction conditions (C_H2O2 = 400 mM, initial pH = 9). Furthermore, this Co–N-graphene catalyst enabled strong synergy with HCO₃⁻ in accelerating MB degradation, whereas the scavenger experiment implied that the synergy herein differed significantly from the current Co²⁺–HCO₃⁻ reaction system, in which contribution of O₂˙⁻ was only validated with a Co–N-graphene catalyst. Therefore, this work developed a novel catalyst for boosting ¹O₂ production from H₂O₂ activation and will extend the inventory of catalysts for advanced oxidation processes.

A graphene-supported highly dispersed cobalt catalyst with abundant Co–N_x active sites was synthesized to boost ¹O₂ production from H₂O₂ activation, exhibiting excellent degradation efficiency towards the model organic pollutant methylene blue.     

Pseudo in situ construction of high-performance thermoelectric composites with a dioxothiopyrone-based D–A polymer coating on SWCNTs

Organic polymer/inorganic particle composites with thermoelectric (TE) properties have witnessed rapid progress in recent years. Nevertheless, both development of novel polymers and optimization of compositing methods remain highly desirable. In this study, we first demonstrated a simulated in situ coagulation strategy for construction of high-performance thermoelectric materials by utilizing single-walled carbon nanotubes (SWCNTs) and a new D–A polymer TPO-TTP12 that was synthesized via incorporating dioxothiopyrone subunit into a polymeric chain. It was proven that the preparation methods have a significant influence on thermoelectric properties of the TPO-TTP12/SWCNT composites. The in situ prepared composite films tend to achieve much better thermoelectric performances than those prepared by simply mixing the corresponding polymer with SWCNTs. As a result, the in situ compositing obtains the highest Seebeck coefficient of 66.10 ± 0.05 μV K⁻¹ at the TPO-TTP12-to-SWCNT mass ratio of 1/2, and the best electrical conductivity of up to 500.5 ± 53.3 S cm⁻¹ at the polymer/SWCNT mass ratio of 1/20, respectively; moreover, the power factor for the in situ prepared composites reaches a maximum value of 141.94 ± 1.47 μW m⁻¹ K⁻², far higher than that of 104.68 ± 0.86 μW m⁻¹ K⁻² for the by-mixing produced composites. This indicates that the dioxothiopyrone moiety is a promising building block for constructing thermoelectric polymers, and the simulated in situ compositing strategy is a promising way to improve TE properties of composite materials.

High-performance thermoelectric composites with a dioxothiopyrone unit have been constructed utilizing SWCNTs and polymer TPO-TTP12via a simulated in situ compositing strategy based on the coagulation method.     

Rice husk biochar modified-CuCo2O4 as an efficient peroxymonosulfate activator for non-radical degradation of organic pollutants from aqueous environment

A series of rice husk biochar (RHBC) modified bimetallic oxides were prepared using a simple pyrolysis method to activate peroxymonosulfate (PMS) for the degradation of acid orange G (OG). The results demonstrated that 50 mg L⁻¹ OG was completely decomposed by 1 mM PMS activated with 100 mg L⁻¹ RHBC–CuCo₂O₄ within 15 min at initial pH 3.4. The OG degradation rate constant k of RHBC–CuCo₂O₄/PMS (0.95 × 10⁻¹ min⁻¹) was five times greater than that of CuCo₂O₄/PMS (0.19 × 10⁻¹ min⁻¹), suggesting that the introduction of RHBC significantly improved the activity of bimetallic oxides. The effects of the initial pH, catalyst dosage, PMS concentration and reaction temperature on OG removal were also studied. The degradation products of OG were analysed using a gas chromatography-mass spectrometer (GC-MS). Electron paramagnetic resonance (EPR) and quenching experiments showed that singlet oxygen (¹O₂) was the main active species. The RHBC–CuCo₂O₄/PMS oxidation system is not only unaffected by inorganic anions (Cl⁻, NO₃⁻, HCO₃⁻) and humic acid (HA), but also could remove other typical pollutants of acetaminophen (ACT), sulfathiazole (STZ), rhodamine B (RhB), and bisphenol A (BPA). These findings show that RHBC–CuCo₂O₄ has great potential for practical applications in the removal of typical organic pollutants.

A series of rice husk biochar (RHBC) modified bimetallic oxides were prepared using a simple pyrolysis method to activate peroxymonosulfate (PMS) for the degradation of acid orange G (OG).     

Novel potentiometric sensors for determination of ondansetron hydrochloride in pure and dosage form

A new and sensitive potentiometric method has been developed and characterized for four novel sensors responsive to ondansetron hydrochloride. The potentiometric sensor method includes advancement of ondansetron hydrochloride sensors using a membrane comprised of molybdophosphoric acid (MPA) and ondansetron as an electro-active material in a polyvinylchloride (PVC) matrix membrane plasticized with di-butyl phthalate (DBPH), ortho-nitrophenyloctyl ether (O-NPOE), di-octyl phthalate (DOPH), or di-butyl phosphate (DBP). The validity of sensors in the present work has been examined, and steady and reproducible responses were obtained over the concentration ranges of 7.3 × 10⁻⁵ to 1.0 × 10⁻², 6.6 × 10⁻⁶ to 1.0 × 10⁻², 1.0 × 10⁻⁵ to 1.0 × 10⁻², and 2.0 × 10⁻⁵ to 1.0 × 10⁻² M for DBPH-, O-NPOE-, DOPH-, and DBP-ondansetron, respectively. The sensors revealed Nernstian gradients of 59.61 ± 0.50, 57.71 ± 0.23, 53.01 ± 0.14, and 53.20 ± 0.35 mV per decade individually with pH ranges of 2.5–5.5 in DBPH and 3.5–5.0 in O-NPOE electrodes, and 4.0–5.5 for both individual DOPH and DBP plasticized film-based sensors. The time responses for the sensors were 30, 32, 31, and 29 s for DBPH-, O-NPOE-, DOPH-, and DBP-ondansetron, respectively. The developed sensors also exhibited high selectivity towards ondansetron hydrochloride against different interfering species of inorganic particles with long-term stability of approximately 41, 36, 18, and multiple days for the DBPH, O-NPOE, DOPH, and DBP electrodes.

A new and sensitive potentiometric method has been developed and characterized for four novel sensors responsive to ondansetron hydrochloride.