Anisotropic thermal conductive properties of cigarette filter-templated graphene/epoxy composites

Herein, a cigarette filter-templated graphene/epoxy composite was prepared with enhanced thermal conductive properties. The through-plane thermal conductivity of the epoxy composite was up to 1.2 W mK⁻¹, which was 4 times that of it in the in-plane (0.298 W mK⁻¹) after only 5 filtration cycles. The thermal conductive anisotropy and improvement in the through-plane thermal conductivity of the epoxy composite were attributed to the particular structure of cigarette filter-templated graphene in the epoxy matrix. The unique structure formed effective conductive pathways in the composite to improve the thermal transportation properties. The excellent thermal transportation properties allow the epoxy composite to be used as an efficient heat dissipation material for thermal management applications.

We report a facile method to prepare cigarette filter-templated graphene/epoxy composites with excellent thermal transport performance.     

A 2D metal–organic framework/reduced graphene oxide heterostructure for supercapacitor application

Metal organic frameworks (MOFs) with two dimensional (2D) nanosheets have attracted special attention for supercapacitor application due to their exceptional large surface area and high surface-to-volume atom ratios. However, their electrochemical performance is greatly hindered by their poor electrical conductivity. Herein, we report a 2D nanosheet nickel cobalt based MOF (NiCo-MOF)/reduced graphene oxide heterostructure as an electrode material for supercapacitors. The NiCo-MOF 2D nanosheets are in situ grown on rGO surfaces by simple room temperature precipitation. In such hybrid structure the MOF ultrathin nanosheets provide large surface area with abundant channels for fast mass transport of ions while the rGO conductive and physical support provides rapid electron transport. Thus, using the synergistic advantage of rGO and NiCo-MOF nanosheets an excellent specific capacitance of 1553 F g⁻¹ at a current density of 1 A g⁻¹ is obtained. Additionally, the as synthesized hybrid material showed excellent cycling capacity of 83.6% after 5000 cycles of charge–discharge. Interestingly, the assembled asymmetric device showed an excellent energy density of 44 W h kg⁻¹ at a power density of 3168 W kg⁻¹. The electrochemical performance obtained in this report illustrates hybridization of MOF nanosheets with carbon materials is promising for next generation supercapacitors.

In this 2D NiCo-MOF/rGO hybrid, the MOF nanosheets provide abundant active sites while the conductive rGO provide rapid electron transport.     

Practical PBT/PC/GNP composites with anisotropic thermal conductivity

Most of the highly thermally conductive polymer-based composites currently face problems that must be solved before they can be directly used in industrial production. Herein, a practical polybutylene terephthalate (PBT)/polycarbonate (PC)/graphite nanoplatelet (GNP) thermally conductive composite with relative low filler content was prepared by a conventional melt-blending technique. GNPs selectively distributed and oriented in the PBT phase afford the composite a low percolation threshold and anisotropic thermal conductivity. Investigation of the influence of filler content on the final comprehensive performance showed that a prepared PBT/PC/GNP composite with 20 vol% GNPs exhibited superior performance in thermal conductivity, heat resistance, and mechanical properties. The in-plane and through-plane thermal conductivities of the composite were 5.82 W m⁻¹ K⁻¹ and 1.06 W m⁻¹ K⁻¹, respectively, which were increased by 2430% and 361% as compared to that of a neat PBT/PC blend. The Vicat softening temperature increased by 17.7 °C and reached 213.7 °C, while the mechanical properties also maintained a good application level.

The selective distribution of thermally conductive fillers in a co-continuous polymer blends provides an industrialized preparation method that takes into account both the properties and functions of thermally conductive composites.     

Modified halloysite nanotube filled polyimide composites for film capacitors: high dielectric constant,low dielectric loss and excellent heat resistance

In this work, halloysite nanotubes (HNTs) were chosen as the fillers and high performance polyimide (PI) as the matrix to form a series of dielectric composite materials with high dielectric constant, low dielectric loss and excellent heat resistance. Firstly, KH550 was used to modify the surface of HNTs to make sure of a good dispersion of HNTs into the polymer. The results showed that the addition of KH550 modified HNTs (K-HNTs) can improve the dielectric constant of the composite films while maintaining their excellent dielectric loss properties. To further increase the dielectric constant of the HNTs/PI composites, conductive polyaniline (PANI) was used to coat the surface of HNTs to obtain PANI modified HNTs (PANI-HNTs). Compared with the K-HNTs filled systems, the dielectric constant of the PANI-HNTs/PI nanocomposite films is greatly enhanced. The highest dielectric constant of the PANI-HNTs/PI films can achieve 17.3 (100 Hz) with a low dielectric loss of 0.2 (100 Hz). More importantly, the as-prepared composite films have high breakdown strengths (>110.4 kV mm⁻¹) and low coefficients of thermal expansion, as low as 7 ppm per °C, and a maximum discharge energy density of 0.93 J cm⁻³. Also, such properties are maintained stably up to 300 °C, which is critical for manufacturing heat-resisting film capacitors.

Halloysite nanotubes (HNTs) were chosen as the fillers and polyimide (PI) as the matrix to form a series of composites with excellent dielectric properties and thermostabilities.     

Ultrathin flexible graphene films with high thermal conductivity and excellent EMI shielding performance using large-sized graphene oxide flakes

As the demand for wearable and foldable electronic devices increases rapidly, ultrathin and flexible thermal conducting films with exceptional electromagnetic interference (EMI) shielding effectiveness (SE) are greatly needed. Large-sized graphene oxide flakes and thermal treatment were employed to fabricate lightweight, flexible and highly conductive graphene films. Compared to graphene films made of smaller-sized flakes, the graphene film made of large-sized flakes possesses less defects and more conjugated domains, leading to higher electrical and higher thermal conductivities, as well as higher EMI SE. By compressing four-layer porous graphene films together, a 14 μm-thick graphene film (LG-4) was obtained, possessing EMI SE of 73.7 dB and the specific SE divided by thickness (SSE/t) of 25 680 dB cm² g⁻¹. The ultrahigh EMI shielding property of the LG-4 film originates from the excellent electrical conductivity (6740 S cm⁻¹), as well as multi-layer structure composed of graphene laminates and insulated air pores. Moreover, the LG-4 film shows excellent flexibility and high thermal conductivity (803.1 W m⁻¹ K⁻¹), indicating that the film is a promising candidate for lightweight, flexible thermal conducting film with exceptional EMI shielding performance.

As the demand for wearable and foldable electronic devices increases rapidly, ultrathin and flexible thermal conducting films with exceptional electromagnetic interference (EMI) shielding effectiveness (SE) are greatly needed.     

Epoxy composite with high thermal conductivity by constructing 3D-oriented carbon fiber and BN network structure

As electronic devices tend to be integrated and high-powered, thermal conductivity is regarded as the crucial parameter of electronic components, which has become the main factor that limits the operating speed and service lifetime of electronic devices. However, constructing continuous thermal conductive paths for low content particle fillers and reducing interface thermal resistance between fillers and matrix are still two challenging issues for the preparation of thermally conductive composites. In this study, 3D-oriented carbon fiber (CF) thermal network structures filled with boron nitride flakes (BN) as thermal conductive bridges were successfully constructed. The epoxy composite was fabricated by thermal conductive material with a 3D oriented structure by the vacuum liquid impregnation method. This special 3D-oriented structure modified by BN (BN/CF) could efficiently broaden the heat conduction pathway and connected adjacent fibers, which leads to the reduction of thermal resistance. The thermal conductivity of the boron nitride/carbon fiber/epoxy resin composite (BN/CF/EP) with 5 vol% 10 mm CF and 40 vol% BN reaches up to 3.1 W m⁻¹ K⁻¹, and its conductivity is only 2.5 × 10⁻⁴ S cm⁻¹. This facile and high-efficient method could provide some useful advice for the thermal management material in the microelectronic field and aerospace industry.

As electronic devices tend to be integrated and high-powered, thermal conductivity is regarded as the crucial parameter of electronic components, which is the main factor that limits the operating speed and service lifetime of electronic devices.     

Synergistic effect of reduced graphene oxide/carbon nanotube hybrid papers on cross-plane thermal and mechanical properties

Graphene paper has attracted great attention as a heat dissipation material due to its excellent thermal conductivity and mechanical properties. However, the thermal conductivity of graphene paper in the normal direction is relatively poor. In this work, the cross-plane thermal conductivities (K_⊥) and mechanical properties of the reduced graphene oxide/carbon nanotube papers with different CNT loadings were studied systematically. It was found that the K_⊥ decreased from 0.0393 W m⁻¹ K⁻¹ for 0 wt% paper to 0.0250 W m⁻¹ K⁻¹ for 3 wt% paper, and then increased to 0.1199 W m⁻¹ K⁻¹ for 20 wt% paper. The papers demonstrated a maximum elastic modulus of 6.1 GPa with 10 wt% CNT loading. The CNTs acted as scaffolds to restrain the graphene sheets from corrugating and to reinforce the mechanical properties of the hybrid papers. The more CNTs that filled the gaps between graphene sheets, the greater the number of channels of the transmission of phonons and the looser the structure in the cross-plane direction. Further mechanism analysis revealed the synergistic effects of CNT loadings and graphene sheets on enhancing the thermal and mechanical performance of the papers.

The top-view SEM images for (a) rGO, (b) rGO/CNT-3%, (c) rGO/CNTs-20% and the corresponding schematic diagram of photon transmission with different spacer CNTs loadings (a-i, b-ii, c-iii).     

Flexible high dielectric thin films based on cellulose nanofibrils and acid oxidized multi-walled carbon nanotubes

Flexible high dielectric materials are of prime importance for advanced portable, foldable and wearable devices. A series of flexible high dielectric thin films based on cellulose nanofibrils (CNF) and acid oxidized multi-walled carbon nanotubes (o-MWCNT) was prepared in aqueous solution. Though no organic solvent was involved during the preparation, the SEM images showed that o-MWCNTs have good distribution within the CNF matrix. The dielectric constant of CNF/o-MWCNT (6.2 wt%) composite films was greatly increased from 25.24 for pure CNF to 73.88, while the loss tangent slightly decreased from 0.70 to 0.68, and the AC conductivity decreased from 3.15 × 10⁻⁷ S cm⁻¹ for CNF to 1.77 × 10⁻⁷ S cm⁻¹ (at 1 kHz). The abnormal decrease of loss tangent and AC conductivity were attributed to the introduction of oxide-containing groups on the surface of MWCNTs. The nanocomposite films showed excellent flexibility such that they could be bent a thousand times without visible damage. The presence of MWCNTs also helped to improve the thermal stability of the composite films. The excellent dielectric and mechanical properties of the CNF/o-MWCNT composite film demonstrate its great potential to be utilized in the field of energy storage.

The acid oxidized MWCNTs have excellent dispersity in CNF, resulting in outstanding dielectric properties of the flexible CNF/o-MWCNT nanocomposite films.     

ZnSe nanoparticles dispersed in reduced graphene oxides with enhanced electrochemical properties in lithium/sodium ion batteries

A ZnSe-reduced graphene oxide (ZnSe-rGO) nanocomposite with ZnSe dispersed in rGO is prepared via a one-step hydrothermal method and applied as the anode materials for both lithium and sodium ion batteries (LIBs/SIBs). The as-prepared composite exhibits greatly enhanced reversible capacity, excellent cycling stability and rate capability (530 mA h g⁻¹ after 100 cycles at 500 mA g⁻¹ in LIBs, 259.5 mA h g⁻¹ after 50 cycles at the current density of 100 mA g⁻¹ in SIBs) compared with bare ZnSe in both lithium and sodium storage. The rGO plays an influential role in enhancing the conductivity of the nanocomposites, buffering the volume change and preventing the aggregation of ZnSe particles during the cycling process, thus securing the high structure stability and reversibility of the electrode.

ZnSe-rGO nanocomposite with ZnSe dispersed in reduced graphene oxides is studied as an anode for lithium and sodium ion batteries (LIBs/SIBs).     

Enhancing thermal conductivity of polyimide composite film by electrostatic self-assembly and two-step synergism of Al2O3 microspheres and BN nanosheets

To improve the perfection of a three-dimensional thermally conductive network in polyimide (PI) composite film and with respect to the economy and simplicity of processing, a strategy of the two-step synergism of Al₂O₃ microspheres and hexagonal boron nitride (BN) nanosheets was proposed. First, BN nanosheet-coated Al₂O₃ microspheres (Al₂O₃@BN) were prepared by electrostatic self-assembly method for the first step of the synergism. Then, the Al₂O₃@BN&BN/PI composite film containing Al₂O₃@BN and BN was fabricated by a two-step method for the second step of the synergism, and was systematically characterized. With an optimized mass ratio of 2 : 1 of Al₂O₃@BN to BN, the thermal conductivity of the 35 wt% Al₂O₃@BN&BN/PI composite film reached 3.35 W m⁻¹ K⁻¹, and was increased by 1664% compared to that of pure PI. The synergism of the Al₂O₃ and BN was the most significant in the Al₂O₃@BN&BN/PI composite film with the thermal conductivity, which was 36.6%, 23% and 22% higher than that of the Al₂O₃/PI, BN/PI and Al₂O₃@BN/PI composite films, respectively. The enhancement mechanism of heat conduction was clearly demonstrated. The BN coated on the surface of Al₂O₃ mainly played a bridging role between the Al₂O₃ and the BN network, which improved the perfection of the thermally conductive network. The Al₂O₃@BN segregated the PI matrix to construct the BN network with the typical segregated structure in the composite film, resulting in an efficient thermally conductive network. This work provided a novel strategy for the preparation of conductive polymer composites.

A strategy of electrostatic self-assembly and two-step synergism was proposed to significantly improve the thermal conductivity of the PI composite film.     

Hot pressing-induced alignment of hexagonal boron nitride in SEBS elastomer for superior thermally conductive composites

Styrene–ethylene–butylene–styrene (SEBS) composite films containing well-dispersed and highly aligned hexagonal boron nitride (hBN) platelets were achieved by a ball milling process followed by hot-pressing treatment. An ultrahigh in-plane thermal conductivity of 45 W m⁻¹ K⁻¹ was achievable in the SEBS composite film with 95 wt% hBN. The corresponding out-of-plane thermal conductivity was also as high as 4.4 W m⁻¹ K⁻¹. The hBN/SEBS composite film was further used to cool a CPU connected to a computer, resulting in a decrease by about 4 °C in the stable temperature. Percolation thresholds over 40 wt% and 60 wt% in the hBN/SEBS composites were obtained in the in-plane and out-of-plane directions, respectively. This phenomenon has rarely been reported in polymer composites. Molecular dynamics simulations were also conducted to support this percolation threshold. The linear coefficients of the thermal expansion value of the hBN/SEBS composite with 95 wt% hBN was as low as 16 ppm K⁻¹. This was a significant decrease compared to that of pure SEBS (149 ppm K⁻¹). The proposed strategy provides valuable advice about the heat-transfer mechanism in polymer composites containing oriented two-dimensional materials.

Orientational hBN/SEBS composite films embued with superior thermal conductivity and improved dimensional stability were prepared by hot-pressing treatment.     

An effective utilization of MXene and its effect on electromagnetic interference shielding: flexible,free-standing and thermally conductive composite from MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications. The MXene–PAT-conductive polymer (CP) composites were fabricated by a cost-effective spray coating technique and characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. A new approach has been developed for the synthesis of exfoliated MXene. The MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer composite exhibited good electric conductivity (EC) of 7.813 S cm⁻¹. The composites revealed an excellent thermal properties, which were 0.687 W (m K)⁻¹ thermal conductivity, 2.247 J (g K)⁻¹ heat capacity, 0.282 mm² s⁻¹ thermal diffusivity and 1.330 W s^1/2 m⁻² K⁻¹ thermal effusivity. The composites showed 99.99% shielding efficiency and the MXene–PAT–PANI–PpAP composite (MXPATPA) had EMI shielding effectiveness of 45.18 dB at 8.2 GHz. The reduced form of MXene (r-Ti₃C₂T_x) increased the shielding effectiveness (SE) by 7.26% and the absorption (SE_A) was greatly enhanced by the ant farm like structure. The composites possess excellent thermal and EMI SE characteristics, thus can be applied in areas, such as mobile phones, military utensils, heat-emitting electronic devices, automobiles and radars.

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications.     

Flexible PANI/SWCNT thermoelectric films with ultrahigh electrical conductivity

The effects of polyaniline (PANI) with different polymerization times on the film-forming and thermoelectric properties as well as on the performance of SWCNTs/PANI composites were systematically investigated in this study. It was found that the film-forming and flexibility of PANI films improved with the increase in polymerization time. We showed that a super high conductivity of ∼4000 S cm⁻¹ can be achieved for the SWCNTs/PANI composite film, which is the highest value for the SWCNTs/PANI system at present. Both the electrical conductivity and power factor increase by an order of magnitude than that of pure PANI films and far exceed the theoretical value of the mixture model. These results suggest that the sufficiently continuous and ordered regions on the interlayer between the filler and matrix are key to improve the electrical conductivity of composites. Finally, the maximum PF reaches 100 μW m⁻¹ K⁻² at 410 K for the 0.6CNT/PANI5h. Furthermore, it is found that the composite films have excellent environmental and structural stability. Our results can deepen the understanding of organic–inorganic thermoelectric composite systems and facilitate the practical application of flexible and wearable thermoelectric materials.

Flexible PANI/SWCNT thermoelectric films with ultrahigh electrical conductivity of ~4000 S cm⁻¹. The maximum PF reaches 100 μW m⁻¹ K⁻² at 410 K for the 0.6CNT/PANI.     

Thickness dependent thermal performance of a poly(3,4-ethylenedioxythiophene) thin film synthesized via an electrochemical approach

Polymer-based thermal interface materials (TIMs) have attracted wide attention in the field of thermal management because of their outstanding properties including light weight, low cost, corrosion resistance and easy processing. However, the low thermal conductivity (∼0.2 W m⁻¹ K⁻¹) of the intrinsic polymer matrix largely degrades the overall thermal performance of polymer-based TIMs even those containing highly thermal conductive fillers. Hence, enhancing the intrinsic thermal conductivity of the polymer matrix is one of the most critical problems needed to be solved. This paper studies the thermal conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) films fabricated via cyclic voltammetry. By controlling the number of cycles in the electrochemical synthesis, different thickness of PEDOT films could be obtained. A time-domain thermoreflectance (TDTR) system was employed to evaluate the thermal performance of such as-prepared PEDOT films. We have demonstrated that a PEDOT film with thickness of 40 nm achieves the highest out-of-plane thermal conductivity of ∼0.60 W m⁻¹ K⁻¹, which is almost three folds the thermal conductivity of commercially available pristine PEDOT:PSS film with similar thickness. The X-ray diffraction spectrum reveals that the PEDOT thin film with high crystallinity at the initial stage of electrochemical synthesis leads to enhanced thermal transportation. The findings in this work not only offer an opportunity to fabricate polymer materials exhibiting enhanced thermal conductivity, but also allow one to adjust the thermal performance of conducting polymers in practical applications.

Enhancing the intrinsic thermal conductivity of PEDOT films via a one-step template-less electrochemical synthesis.     

High electrochemical performance of ink solution based on manganese cobalt sulfide/reduced graphene oxide nano-composites for supercapacitor electrode materials

Large scale supercapacitor electrodes were prepared by 3D-printing directly on a graphite paper substrate from ink solution containing manganese cobalt sulfide/reduced graphene oxide (MCS/rGO) nanocomposites. The MCS/rGO composite solution was synthesized through the dispersion of MCS NPs and rGO in dimethylformamide (DMF) solvent at room temperature. Their morphology and composition were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray diffraction (EDS). The role of rGO on decreasing charge transfer resistance and enhancing ion exchange was discussed. The MCS/rGO electrode exhibits an excellent specific capacitance of 3812.5 F g⁻¹ at 2 A g⁻¹ and it maintains 1780.8 F g⁻¹ at a high current density of 50 A g⁻¹. The cycling stability of the electrodes reveals capacitance retention of over 92% after 22 000 cycles at 50 A g⁻¹.

Large scale supercapacitor electrodes were prepared by 3D-printing directly on a graphite paper substrate from ink solution containing manganese cobalt sulfide/reduced graphene oxide (MCS/rGO) nanocomposites.     

Microwave-assisted nanocatalysis: A CuO NPs/rGO composite as an efficient and recyclable catalyst for the Petasis-borono–Mannich reaction

A CuO NP decorated reduced graphene oxide (CuO NPs/rGO) composite was synthesized and characterized using various analytical techniques viz. XRD, TEM, SEM, UV-Vis, FT-IR, EDX, XPS and CV. The activity of the catalyst was probed for the Petasis-Borono–Mannich (PBM) reaction of boronic acids, salicylaldehydes, and amines under microwave irradiation (MW). The CuO NPs/rGO composite works as a catalyst as well as a susceptor and augments the overall ability of the reaction mixture to absorb MW. The synergistic effect of MW and CuO NPs/rGO resulted in an excellent outcome of the reaction as indicated by the high TOF value (3.64 × 10⁻³ mol g⁻¹ min⁻¹). The catalytic activity of the CuO NPs/rGO composite was about 12-fold higher under MW compared to the conventional method. The catalyst was recovered by simple filtration and recycled 8 times without significant loss in activity. This atom-economical protocol includes a much milder procedure, and a catalyst benign in nature, does not involve any tedious work-up for purification, and avoids hazardous reagents/byproducts and the target molecules were obtained in good to excellent yields.

CuO NPs/rGO composite was synthesized and characterized by various analytical techniques an used as a recyclable catalyst for Petasis-borono–Mannich reaction under microwave irradiation.     

Facile construction of the aerogel/geopolymer composite with ultra-low thermal conductivity and high mechanical performance

In this work, we have successfully prepared a lightweight, highly hydrophobic and superb thermal insulating aerogel/geopolymer composite by a sol–gel immersion method. After silica aerogel was impregnated, the composite exhibited nano-porous structures. Moreover, scanning electron microscopy observations revealed that the aerogel particles were tightly anchored on the geopolymer surface. With several excellent properties (bulk density: 306.5 g cm⁻³, thermal conductivity: 0.0480 W m⁻¹ K⁻¹ and maximum compressive strength: 0.79 MPa) the as-prepared composite shows great potential to be applied in the thermal insulation field.

In this work, we have successfully prepared a lightweight, highly hydrophobic and superb thermal insulating aerogel/geopolymer composite by a sol–gel immersion method.     

Electrochemical properties of TiOx/rGO composite as an electrode for supercapacitors

Transition metal oxides are known as the active materials for capacitors. As a class of transition metal oxide, Magnéli phase TiO_x is particularly attractive because of its excellent conductivity. This work investigated the electrochemical characteristics of TiO_x and its composite with reduced graphene oxide (rGO). Two types of TiO_x, i.e. low and high reduction extent, were employed in this research. Electrochemical impedance spectroscopy revealed that TiO_x with lower reduction extent delivered higher electro-activity and charge transfer resistance at the same time. However, combining 10% of low-reduction state TiO_x and rGO using a simple mixing process delivered a high specific capacitance (98.8 F g⁻¹), which was higher than that of standalone rGO (49.5 F g⁻¹). A further improvement in the specific capacitance (102.6 F g⁻¹) was given by adding PEDOT:PSS conductive polymer. Results of this research gave a basic understanding in the electrochemical behavior of Magnéli phase TiO_x for the utilization of this material as supercapacitor in the future.

This work investigated the electrochemical characteristics of TiO_x and its composite with reduced graphene oxide.     

N and S co-doped graphene enfolded Ni–Co-layered double hydroxides: an excellent electrode material for high-performance energy storage devices

The performance of hybrid supercapacitors (HSCs) can be increased via the selection of higher capacitive electrode materials. Thus, layered double hydroxides (LDHs) have received extensive consideration in HSCs owing to their good ion-exchange properties, structural flexibility, and large specific surface area. Ni–Co-based LDHs show better specific capacitance, good synergy, and high-rate capability in aqueous electrolytes. However, LDHs suffer from low conductivity, which curbs the charge transfer and mass diffusion throughout the electrochemical process. Thus, the high performance of LDH-based supercapacitors is impeded. Hence, composites of LDH and conducting materials are used. Owing to its extraordinary conducting property, huge surface area, and cost-effectiveness, reduced graphene oxide (rGO) is used as conducting material for LDH-based composite electrodes. Moreover, via the incorporation of heteroatoms (N, S, etc.) into rGO, its electrochemical properties are further enhanced. Here, a novel composite electrode is prepared by wrapping Ni–Co-LDH with N and S-co-doped rGO (LDH-rGO-NS) via a hydrothermal process. The XPS C 1s spectra established the existence of N and S doping in the rGO. The electrochemical performance is enhanced due to an excellent ion/charge transfer rate because of N and S co-doping. The LDH-rGO-NS electrode offers a good charge transfer resistance of 0.24 Ω. The obtained anodic and cathodic b-values are 0.73 and 0.72, respectively. An admirable specific capacitance of 1388 F g⁻¹ is accomplished at a sweep rate of 100 mV s⁻¹. Furthermore, the obtained retention capacity is ∼71% after 2000 cycles. Moreover, the achieved specific capacitance is 2193 F g⁻¹ at the discharge current density of 5 A g⁻¹. The excellent electrochemical properties reveal the LDH-rGO-NS composites as encouraging electrode materials for HSCs.

A novel graphene embedded Ni–Co-LDH electrode was developed. The charge transportation rate was enhanced via N and S heteroatom doping, which results in an excellent discharge capacitance of 2193 F g⁻¹ at 5 A g⁻¹.     

Two-step deposition of Ag nanowires/Zn2SnO4 transparent conductive films for antistatic coatings

Silver nanowire (AgNW) networks play an important role in the transparent conductive electrodes or antistatic coatings. In this work, we describe a facile two-step method to fabricate AgNWs/Zn₂SnO₄ composite films. Long AgNWs with a high aspect ratio were prepared through a modified polyol method, in which the organic octylamine hydrochloride rather than the commonly used inorganic chlorides was used as the shape-controlling agent. The AgNW networks were fabricated on the glass substrate, on which the Zn₂SnO₄ film was deposited, forming robust AgNWs/Zn₂SnO₄ composite films. The as-prepared composite films have strong adhesion, high thermal stability, low sheet resistance (5–15 ohm sq⁻¹) and high light transmittance (85–80%), indicating a promising application prospect for transparent conductive electrodes and antistatic coatings.

Robust and stable AgNWs/Zn₂SnO₄ hybrid thin films with a sheet resistance of 5–15 ohm sq⁻¹ and transmittance of 85–80% are fabricated.