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Development of highly functional and durable catalysts in a cost-effective way is a promising approach for practical energy conversion applications. In this study, a novel catalyst, cobalt iron carbide nanoparticles encapsulated by nitrogen doped graphene nanosheets, is successfully synthesized through a simple refluxing strategy followed by a post annealing process. It is found that the catalyst exhibits excellent catalytic activity for oxygen reduction reaction in alkaline medium. The oxygen reduction reaction kinetics of the catalyst mainly follow a 4-electron transferred pathway along with good diffusion limit current density, highly positive onset potential (−0.04 V) and half-wave potential (−0.11 V). In addition to catalytic activity, the catalyst demonstrates advanced superior stability, and excellent methanol tolerance in comparison with commercial platinum catalyst. The impressive catalytic performance of the catalyst is attributed to the unique mesoporous metal-core/graphene-shell architecture in which high interactions between two transition metals and transition metal-carbon synergistically provide enhanced catalytically active sites, accelerate interfacial charge transfer, and optimize oxygen adsorption energy. The results demonstrate that such catalyst can be an alternative low-cost and efficient catalyst for oxygen reduction reaction in energy conversion applications.

The development of new advanced nanostructures based on the hybridization of different carbon nanomaterials to obtain enhanced performance of energy storage devices has attracted considerable attention. Herein, a hierarchical nanostructure of carbon nanotubes supported electrospun carbon nanofiber networks (CNTs@CNFs) was successfully fabricated by using two facile techniques: – electrospinning and chemical vapor deposition (CVD). Such CNTs@CNFs hybrid showed the uniform and high density of CNTs directly grown on the surface of carbon nanofiber networks, leading to the formation of a hierarchical nanostructure with a large surface area and highly porous characteristics. The enhanced interactions between the CNTs and the CNFs networks were found to improve the electrical conductivity and electrochemical stability of the material. Owing to its unique nanoarchitectures and physicochemical properties, the CNTs@CNFs hybrid was demonstrated to be a potential electrode material for an electrochemical capacitor, in which a high specific capacitance of 464.2 F g−1 at 0.5 A g−1 and long-term stability with 97% retention after 10,000 repeated charge–discharge cycles were achieved. The obtained results suggest that the present CNTs@CNFs hybrid is a promising candidate for an electrochemical capacitor in energy storage technologies.

In this study, a facile approach has been successfully applied to synthesize a hierarchical three-dimensional architecture of ultrasmall hematite nanoparticles homogeneously encapsulated in MoS2/nitrogen-doped graphene nanosheets, as a novel non-Pt cathodic catalyst for oxygen reduction reaction in fuel cell applications. The intrinsic topological characteristics along with unique physicochemical properties allowed this catalyst to facilitate oxygen adsorption and sped up the reduction kinetics through fast heterogeneous decomposition of oxygen to final products. As a result, the catalyst exhibited outstanding catalytic performance with a high electron-transfer number of 3.91–3.96, which was comparable to that of the Pt/C product. Furthermore, its working stability with a retention of 96.1% after 30 000 s and excellent alcohol tolerance were found to be significantly better than those for the Pt/C product. This hybrid can be considered as a highly potential non-Pt catalyst for practical oxygen reduction r...

Recently, the research effort on two-dimensional transition metal dichalcogenides/graphene (2D-TMDs/Gr) hybrids has grown. These hybrids are emerging as a promising strategy for the preparation of advanced multifunctional materials with effectively upgraded properties, as well as performances. Due to their outstanding electrical, physical, and chemical properties, these materials have been extensively considered for various applications, both in academia, and industry. This review systematically assesses the important progress to date in the development of 2D-TMDs/Gr hybrids. The synthesis methods of 2D-TMDs/Gr hybrids for fabricating diverse types of nanostructured architectures are highlighted. In addition, the relationships between morphological and structural characteristics, and the physicochemical properties of 2D-TMDs/Gr hybrids, are recognized in detail. This review also discusses recent prospective applications of the 2D-TMDs/Gr hybrids in the areas of energy storage, energy conversion, energy harvesting technologies, and sensors. In summary, although there are still challenges for optimizing the synthesis process and performance of the 2D-TMDs/Gr hybrids, they offer unique candidates for a wide range of promising applications in the future.

In this study, a novel hierarchical porous network of Pt51Pd49 alloy-integrated graphene nanosheet as active catalyst towards ethanol oxidation was fabricated using electroless deposition followed by chemical vapour deposition for the first time. Such materials were obtained as a three-dimensional continuous and non-order porous architecture with good dispersion and uniformity of the ultrasmall Pt51Pd49 nanoalloy particles (∼3 nm) within the graphene nanosheets. As an electrocatalyst, it exhibited excellent catalytic behaviour towards ethanol oxidation with superior conversion, long-term stability and better tolerance towards intermediate's poisoning effect, as compared to commercial Pt black product. The results were associated with the enhanced electroactive surface area and mass transfer possibility of the catalyst due to the formation of an unique porous nanostructure for Pt51Pd49 alloys. In addition, the coating effect of graphene nanosheets over Pt51Pd49 alloy nanoparticles avoided aggregation and dissolution, possibly allowing full utilization of the active sites from all nanoparticles, and thus efficiently improving charge transfer ability and working stability of the catalyst. Owning high quality, good electrochemical performance, and ease of synthesis, the as-synthesized catalyst opens an interesting nanoarchitecture class for efficiently catalyzing ethanol oxidation in fuel cells.

Development of highly efficient adsorbent materials for the wastewater treatment is an excellent, cheap, environmental friendly and sustainable approach. Herein, a novel cotton flower-like hierarchically porous boron nitride (BN) structure was successfully synthesized by pyrolizing a boric acid/melamine mixture at 1100 °C in a controlled flow rate ratio of N 2 /H 2 . The obtained porous BN material with a large specific surface area (SSA) of 1140 m 2 g −1 exhibited high selectivity, fast adsorption rate (∼96% for methylene blue (MB) after 20 min and ∼80% for rhodamine B (RhB) after 10 min) and high adsorption capacities (∼471.2 and 313.4 mg⋅g −1 for MB and RhB, respectively). The excellent selectivity of porous BN material towards dyes adsorption was confirmed from a mixed solution of dye and inorganic salts. In addition, porous BN material remain sustained without losing its adsorption activity even after 10 cycles and exhibited easy regeneration and good reusability which were achieved by a simple heating process. The obtained results indicated that the present porous BN material is a potential candidate for the removal of organic pollutants in water treatment applications.

Nickel-palladium alloy nanoparticles over graphene nanosheets (NiPd alloy NPs/GNS) are synthesized using ammonia-hydrazine method via a surfactant-free hydrothermal process. NiPd alloy NPs/GNS represent a new class of electrocatalyst with enhanced activity and stability for formic acid and ethanol oxidation reactions. The as-prepared catalysts are characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), STEM-elemental mapping, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Cyclic voltammetry (CV) and chronoamperometry (CA) studies reveal that bimetallic alloy nanoparticles exhibit higher catalytic activity than monometallic catalysts toward electro-oxidation reactions. The higher activity is mainly attributed to the strong assembly of bimetallic NiPd alloy NPs over graphene sheets. The novel NiPd alloy NPs/GNS catalysts provide a new strategy for superior electro-catalytic performance in next-generation fuel cells.

A novel 3D nanocomposite of nitrogen doped Co-CNTs over graphene sheets (3D N-Co-CNT@NG) have been successfully fabricated via a simple, scalable and one-step thermal decomposition method. This 3D hierarchical nanostructure provides an admirable conductive network for effective charge transfer and avoids the agglomeration of NG matrices, which examine direct as well as non-enzymatic responses to glucose oxidation and H2O2 reduction at a low potential. The novel electrode showed excellent electrochemical performance towards glucose oxidation, with high sensitivity of 9.05μAcm-2mM-1, a wide linear range from 0.025 to 10.83mM, and a detection limit of 100nM with a fast response time of less than 3s. Furthermore, non-enzymatic H2O2 sensors based on the 3D N-Co-CNT@NG electrode exhibited high sensitivity (28.66μAmM-1cm-2), wide linear range (2.0-7449μM), low detection limit of 2.0μM (S/N=3), excellent selectivity, decent reproducibility and long term stability. Such outstanding electrochemical performance can be endorsed to the large electroactive surface area, unique porous architecture, highly conductive networks, and synergistic interaction between N-Co-CNTs and nitrogen doped graphene (NG) in the novel 3D nanocomposite. This facile, cost-effective, sensitive, and selective glucose as well as H2O2 sensors are also proven to be appropriate for the detection of glucose as well as H2O2 in human serum.

A novel hierarchical nanoporous thin film of AuPt alloy embedded in graphene (AuPt@GR) was successfully synthesized through the self-assembly of ultrafine AuPt nanoparticles (~3 nm) within GR sheets by means of a facile chemical vapor deposition (CVD) procedure without the use of any external organic capping agent and reducing agent. A binder-free sensor based on the AuPt@GR hybrid material was fabricated and its electrocatalytic activity was evaluated by using it to determine epinephrine (EP) in PBS solution (pH=7.4) and in human serum spiked PBS solution. Amperometric measurements of the sensor response showed an extremely low limit of detection (0.9 nM at a signal-to-noise ratio of 3), high sensitivity (1628 µA m M −1 cm −2 ), wide linear detection range (1.5×10 −9 –9.6×10 −6 M), and negligible response to interferents. At the same time, the sensor also exhibited very long-term amperometric stability (4000 s), cyclic voltammetric stability (500 cycles), good reproducibility, and highly accurate detection of EP in real samples. The excellent electrochemical performance was attributed to synergistic effects of Au, Pt, and GR as well as to the formation of a unique nanoporous structure that provided enhanced electrocatalytic activity, a highly electroactive surface, and fast mass transport. These results suggest strong potential of the AuPt@GR hybrids for use in biosensors and bioelectronic devices.

Heteroatom co-doped carbon-based materials have been demonstrated to be an effective way to realize their new functions in electrode materials for energy storage devices. Herein, a novel strategy for synthesis of highly porous nitrogen-sulfur co-doped graphene nanoribbons (NS-GNRs) with enhanced active sites was developed. The highly porous NS-GNR channels provide efficient ion transport path for electrolyte ions, which enhances the overall conductivity and stability of the electrode materials by energising storage sites. The TEM and STEM-EDS analysis revealed that the NS-GNR materials exhibit uniform distribution of N and S heteroatoms into GNRs matrices. The NS-GNR electrode materials exhibited a high specific capacitance of 442 F g −1 at 0.5 A g −1 , excellent rate capability and cycling performance with ∼98.6 % retention of the initial capacitance after 10,000 cycles. Most importantly, the fabricated symmetric supercapacitor device with a wide operating voltage window of ∼1.8 V yield an excellent energy density of ∼23.85 Wh kg −1 , high power density of ∼8753 W kg −1 and superior cycle life (97.9% capacitance retention after 10,000 cycles). Thus, these results exhibit a novel metal-free and low-cost design of electrode materials for high-performance energy storage devices.

Novel supercapacitor electrodes comprising hierarchical architectures with high specific surface areas, unique porosities, excellent conductivities, and admirable mechanical stabilities are necessary for developing high-performance solid-state supercapacitors. Herein, a novel ultra-thin copper nickel sulfide (Cu1−xNixS) nanosheet array supercapacitor electrode was constructed on a 3D Ni backbone through a powerful anion exchange technique and it demonstrated a unique architecture with a substantial degree of porosity. Accordingly, Cu1−xNixS plays an imperative role in the electrochemical energy storage characteristics of the electrode by accomplishing an ultra-high areal capacitance of 5.88 F cm−2 and a specific capacitance of 2672 F g−1 at a current density of 2 mA cm−2 with an excellent rate capability (71.26% capacitance retention at 20 mA cm−2) and a superior cycling performance (97.33% capacitance retention after 10 000 cycles). To design asymmetric supercapacitors (ASCs), Cu1−xNixS and N, S co-doped graphene nanosheets (NSGNSs) are employed as positive and negative electrodes, respectively. Remarkably, the fabricated ASC exhibits a potential window of ∼1.8 V, which demonstrates an ultra-high energy density of ∼94.05 W h kg−1 at 1.09 kW kg−1 as well as an excellent life cycle (95.86% capacitance retention after 10 000 cycles). Owing to this fact, this investigation offers a simple, scalable, and cost-effective approach for the fabrication of other ternary transition metal sulfides (TMSs), emphasizing great prospects in next-generation energy storage applications.

A unique morphology, high specific surface area, extraordinary porosity, and excellent conductive networks are typical favorable properties of pseudocapacitors; however, fully comprehending and interpreting this substantive topic still remains a great challenge. Herein, we present a new strategy for the direct growth of a cobalt monoxide@manganese oxide core–shell nanostructure on 3D Ni foam (CoO@MnO2/Ni foam). This is accomplished by simple, scalable, in situ fabrication methods to produce a material that can be employed as an advanced electrode material for high-energy solid state asymmetric supercapacitors (ASCs). The cost-effective, binder-free 3D CoO@MnO2 core–shell nanostructure delivers excellent electrochemical properties with an ultra-high specific capacitance (1835 F g−1 at a current density of 1 A g−1), tremendous rate capabilities with an extraordinary capacitance of 1198 F g−1 at a current density of 20 A g−1, and outstanding stability (97.7% capacitance retention after 10 000 cycles). ASCs with a maximum potential window of 1.8 V are fabricated by using a 3D CoO@MnO2 core–shell nanohybrid as the positive electrode and N-doped graphene (NG) as the negative electrode in order to validate the outstanding performance for practical energy storage devices. Impressively, the ASCs delivered a high specific capacitance (191 F g−1 at 1 A g−1), excellent energy density (∼85.9 W h kg−1), an ultra-high power density (∼16 769 W kg−1 at 51.7 W h kg−1), and remarkable cycle stability (86.8% capacitance retention after 10 000 cycles). These findings provide a new method to design 3D CoO@MnO2 core–shell nanostructures that are cost-effective and binder-free electrode materials for the development of high-performance energy storage devices.

Sustainable methods are needed for rapid and efficient detection of environmental and food pollutants. The Sudan group of dyes has been used extensively as adulterants in food and also are found to be polluting the soil and water bodies. There have been several methods for detection of Sudan dyes, but most of them are not practical enough for common use. In this study, the electrochemical detection efficiency and stability of gold nanoparticle (AuNPs), silver NPs and Au–Ag bionanocomposites, synthesised by peanut skin extract, modified glassy carbon electrode has been investigated. The synthesised nanomaterial samples were characterised, for their quality and quantity, using ultra–visible spectroscopy, inductive coupled plasma mass spectrophotometer, Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, high‐resolution transmission electron microscope and field emission scanning electron microscope. The nanomaterial hybrid electrodes showed great efficiency and stability in the detection of Sudan IV compared with the other previous electrodes. The peak current of the Sudan IV oxidation and reduction was found to be proportional to its concentration, in the range of 10–80 µM, with a detection limit of 4 µM. The hybrid electrodes showed 90% stability in detection for 20 cycles.

Herein, we present a novel strategy for the synthesis of an iron nitride nanoparticles-encapsulated nitrogen-doped graphene (FeN NPs/NG) core-shell hierarchical nanostructure to boost the electrochemical performance in a highly sensitive, selective, reproducible, and stable sensing platform for nicotinamide adenine dinucleotide (NADH). This core-shell hierarchical nanostructure provides an excellent conductive network for effective charge transfer and avoids the agglomeration and restacking of NG sheets, which provides better access to the electrode material for NADH oxidation. The FeN NPs/NG core-shell hierarchical nanostructure demonstrates direct and mediatorless responses to NADH oxidation at a low potential. This material displays a high sensitivity of 0.028μA/μMcm(2), a wide linear range from 0.4 to 718μM, and a detection limit of 25nM with a fast response time of less than 3s. The interferences from common interferents, such as glucose, uric acid, dopamine, and ascorbic acid, are negligible. The fabricated sensor was further tested for the determination of NADH in human blood serum. The resulting high sensitivity, excellent selectivity, outstanding stability, and good reproducibility make the proposed FeN NPs/NG core-shell hierarchical nanostructure as a promising candidate for biomedical applications.

A novel gold nanoparticle-anchored nitrogen-doped graphene (AuNP/NG) nanohybrid was synthesized through a seed-assisted growth method, as an effective electrocatalyst for glucose and dopamine detection. The AuNP/NG nanohybrids exhibited high sensitivity and selectivity toward glucose and dopamine sensing applications. The as-synthesized nanohybrids exhibited excellent catalytic activity toward glucose, with a linear response throughout the concentration range from 40μM to 16.1mM, a detection limit of 12μM, and a short response time (∼ 10s). It also exhibited an excellent response toward DA, with a wide detection range from 30nM to 48μM, a low detection limit of 10nM, and a short response time (∼ 8s). Furthermore, it also showed long-term stability and high selectivity for the target analytes. These results imply that such nanohybrids show a great potential for electrochemical biosensing application.

Hybrid materials based on recycled acrylonitrile butadiene styrene (re-ABS) and nitrile rubber (NBR) upgraded by montmorrilonite nanofil 15 (N15) were prepared by melt processing. The morphology and structure of the nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM) analyses. As revealed by SEM, NBR and N15 were homogeneously dispersed in the re-ABS matrix. The XRD and TEM studies demonstrated that N15 was mainly located in the re-ABS matrix in the form of an intercalated-exfoliated mixed structure that led to an increase of the melting viscosity of the materials. The mechanical properties of the nanocomposites showed a good balance when adding 1 phr (parts per hundred parts of resin) of N15 into the re-ABS/NBR (90/10) blend. Furthermore, the thermal stability of the nanocomposites was also improved in the presence of NBR and N15.

Novel vanadium nitride/nitrogen-doped graphene (VN/NG) composite was fabricated and used as stable high performance anode materials for supercapacitors. The VN/NG composite anode material exhibited excellent rate capability, outstanding cycling stability, and superior performance. FE-SEM and TEM studies of VN/NG composite revealed that ultra-thin VN nanostructures were homogeneously distributed on flexible NG nanosheets. The NG provided a highly conductive network to boost the charge transport involved during the capacitance generation and also aided the dispersion of nanostructured VN within the NG network. The synergetic VN/NG composite exhibited an ultra-high specific capacitance of 445 F g −1 at 1 Ag −1 with a wide operation window (−1.2 to 0 V) and showed outstanding rate capability (98.66% capacity retention after 10,000 cycles at 10 Ag −1 ). The VN/NG electrode offered a maximum energy density (∼81.73 Wh kg −1 ) and an ultra-high power density (∼28.82 kW kg −1 at 51.24 Wh kg −1 ). The cycling performance of the VN/NG composite was superior to that of pure VN nanostructure. These finding open a new path way to the designated fabrication of VN/NG composite as anode materials in the development of high performance energy storage devices.

A novel route for in-situ synthesis of high-quality gold nanoparticles-encapsulated few layered graphene (AuNP-FLG) nanohybrids has been established. The AuNP-FLG nanohybrids were successfully synthesized by chemical vapor deposition technique and used as an electrocatalyst for high sensitive non-enzymatic glucose sensors. The amperometric response of the AuNP-FLG based electrode achieved an excellent electrocatalytic activity towards glucose oxidation with a wide linear detection range of 6 μM–28.5 mM, low detection limit of 1 μM and a sensitivity of 0.195 μA mM−1 cm−2 at operating potential of 0.0 V. Furthermore, the electrode also showed long-term stability (retention of 95.4% after two week) with negligible interference from ascorbic acid, 4-acetamidophenol and uric acid. The results implied that AuNP-FLG could be a promising electrode material in the development of non-enzymatic glucose sensors.

A novel strategy for the synthesis of high-quality ternary cobalt copper sulfide nanoparticles (NPs) anchored on nitrogen doped graphene nanosheets (Co2CuS4/NG) was developed via a one-pot solvothermal method. FE-SEM and TEM images showed that the Co2CuS4 NPs with an average size of ∼21 nm were anchored to NG nanosheets. The NG nanosheets provide a large surface area to reduce self-aggregation and confine the shape of the Co2CuS4 NPs for a highly conductive network to boost the charge transport properties of energy storage devices. Impressively, the synergetic Co2CuS4/NG composite showed a high specific capacitance of ∼1005 F g−1 at 1 A g−1, excellent rate capability (770 F g−1 at 50 A g−1), and outstanding stability (96.3% capacitance retention after 5000 cycles). The electrochemical performance of the Co2CuS4/NG composite was superior to that of monometallic CoS/NG, Cu2S/NG composite, pure Co2CuS4, and NG. An asymmetric supercapacitor device fabricated using the Co2CuS4/NG composite as the positive electrode material and NG as the negative electrode material illustrates the outstanding performance for practical energy storage devices. The asymmetric supercapacitor device delivers superb energy density (53.3 W h kg−1), high power density (∼10 936 W kg−1 at 38.4 W h kg−1), and a long-cycle life (∼4000 times).

A novel three-dimensional (3D) hierarchical hybrid architecture, consisting of in situ designed cobalt-encapsulated nitrogen doped carbon nanotubes (Co–NCNTs) grown on nitrogen doped graphene (NG), is fabricated for asymmetric supercapacitors. When evaluated as an electrode material for supercapacitors, the 3D hybrid has an excellent energy density, outstanding rate capability and long-cycle life compared with commercial electrode materials. The decent electrochemical performance is comparable to most of the earlier reported results and the synergistic effect boosts the pseudocapacitive performance. The constructed hybrid exhibits excellent energy storage characteristics, which result in an ultra-high specific capacitance of 2568 F g−1 at 2 A g−1 and excellent rate capability with an extraordinary capacitance of 1594 F g−1 at 100 A g−1 (96.64% capacitance retention after 20000 cycles). The improvement in the outstanding electrochemical performance can be attributed to the unique morphology, extraordinary porosity, excellent conductive networks, and the intense networking of Co–NCNT and NG nanosheets in the 3D hybrid. An asymmetric supercapacitor fabricated using the 3D NG/Co–NCNT hybrid as the positive electrode and NG as the negative electrode demonstrates exceptional performance for practical energy storage devices. The assembled asymmetric supercapacitors provide a greater energy density (∼88.44 W h kg−1), an ultra-high power density (∼17991 W kg−1 at 56.97 W h kg−1), and outstanding cyclability (∼10000 times).

A high quality graphene-encapsulated AuAg alloy (AuAg-GR) nanohybrid with homogeneous structure and good reproducibility over a desired area was successfully fabricated. Taking benefits of the unique architecture, such nanohybrid was employed as an efficient electrocatalyst for sensing application. The AuAg-GR based sensor could sensitively detected neurotransmitter serotonin (5-HT) with wide linear detection range (2.7nM to 4.82μM), very low detection limit (1.6nM), negligible interference, and excellent reproducibility. In addition, AuAg-GR based sensor accurately determined 5-HT in human serum samples. This is due to the enhanced catalytic activity of GR nanosheets-encapsulated AuAg nanostructures, which possessed well monodispersion of AuAg alloy, greater electrochemical active sites, and good charge transfer possibility. The obtained results imply that such nanohybrid is a potential candidate for synthesizing electrochemical sensors in requirement of high sensitivity, long-term stability, and good reproducibility.

In an effort to develop electrocatalysts associated with effective design, testing, and fabrication, novel porous gold-palladium nanoalloy network-supported graphene (AuPd@GR) nanohybrids were successfully synthesized via electroless deposition followed by a chemical vapor deposition (CVD) method for the first time. The AuPd@GR nanohybrids were obtained as a continuous, porous, transparent, bendable, and ultrathin film with good assembly of the AuPd nanoalloy particles (

A nanohybrid based on porous and hollow interior structured LaNiO3 stabilized nitrogen and sulfur codoped graphene (LaNiO3/N,S-Gr) is successfully synthesized for the first time. Such a nanohybrid as an electrocatalyst shows high catalytic activity for oxygen reduction reaction (ORR) in O2-saturated 0.1 m KOH media. In addition, it demonstrates a comparable catalytic activity, longer working stability, and much better alcohol tolerance compared with commercial Pt/C behavior in same experiment condition. The obtained results are attributed to synergistic effects from the enhanced electrocatalytic active sites on the rich pore channels of porous hollow-structured LaNiO3 spheres and heteroatom doped efficiency on graphene structure. In addition, N,S-Gr can meritoriously stabilize monodispersion of the LaNiO3 spheres, and act as medium bridging for high electrical conductivity, thereby providing large active surface area for O2 adsorption, accelerating reduction reaction, and improving electrochemical stability. Such a hybrid opens an interesting class of highly efficient non-Pt catalysts for ORR in alkaline media.

A newly designed counter electrode (CE) composed of a hybridized structure of iron nitride (FeN) core–shell nanoparticles grown on nitrogen-doped graphene (NG) is presented for application in dye-sensitized solar cells (DSSCs). The FeN core–shell nanoparticles on NG show an excellent electrocatalytic activity and lower charge-transfer resistance (Rct) towards the CE (I−/I3−) redox reaction in DSSCs. The hybridized electrode exhibits remarkable cycling stability even after 500 cycles. The energy conversion efficiency of a DSSC cell with core–shell FeN/NG nanohybrids as the CE reaches 10.86%, which is superior to the energy conversion efficiency of 9.93% for a cell with a conventional Pt CE under the same experimental conditions. This work provides a novel approach to fabricate catalytically active electrodes for DSSCs and promotes the development of metal nitride-based electrodes for photovoltaic applications.