Hydrangea-like NiMoO4-Ag/rGO as Battery-type electrode for hybrid supercapacitors with superior stability
Graphical abstract
Introduction
NiMoO4, a typical low-cost and environmentally friendly spinel, presents a high reversible capacity and electrochemical activity because of its feasible oxidation state[1]. Besides, the inverse spinel structure of NiMoO4 can provide ion channels and achieve effective charge storage as electrode materials for supercapacitors[2], [3], [4]. However, NiMoO4 materials face two difficult problems of low conductivity and poor cycling stability, which are associated with slow charge/ion transfer, as well as an excessive volume change after the process of electrochemical cycles[5], [6]. They lead to that NiMoO4 materials show an essentially low dynamics of electrode reactions in supercapacitors, and their specific capacitance are much lower than the theoretical value (≥3000 F g−1)[7], such as reported NiMoO4 nanorods[8], porous worm-like NiMoO4[9] and NiMoO4 nanosheets[10], which exhibited 594, 1088.5 and 1221.2 F g−1 at 1 A g−1, respectively. Moreover, the breakdown of NiMoO4 structure may result in poor cycle life[11]. For example, the mesoporous NiMoO4 nanorod/reduced graphene oxide composites[12] and mesoporous β-NiMoO4 nanorods[13] maintain 81.1% and 80.2% of its initial specific capacitance.
It is noteworthy that combining with carbon materials can improve conductivity and stability of NiMoO4, such as NiMoO4/active carbon[14], NiMoO4/hollow spheres of carbon[15] and NiMoO4/graphene[16], et al. The reported composite of NiMoO4 and carbon material exhibited good rate performance, high specific capacitance and long cycle life, which were contributed to the enhanced electrical conductivity and stability. Among these carbon materials, reduced graphene oxide (rGO) is a popular and promising nanocarrier because of its large specific surface area, long-range π-π conjugated bonds, and excellent electro-response and mechanical properties [17], [18]. For example, Rastabi[16] et al. prepared the 3D NiMoO4/rGO composite by using a co-precipitation method, in which the oxygen-containing functional groups on graphene oxide have been removed by ammonia solution. The electrochemical results of the 3D NiMoO4/rGO composite showed that its specific capacitance can reach 932 F g−1. However, the improvement in specific capacitance of NiMoO4/rGO composite is limited when compared with that of NiMoO4. According to previous reports, combining NiMoO4 and metal with good conductivity is an effective strategy to improve the performance of NiMoO4 for supercapacitors [19], [20], [21], while Ag is a good candidate. Especially, the Ag nanoparticles have large active surface areas and can enhance charge transfer during electrochemical testing.
Based on this, a study is designed to construct NiMoO4-Ag/rGO composite by a facile two-step hydrothermal process. It can be seen from the morphological characterization that rGO and NiMoO4 form a hydrangea-like structure with lots of stacking layers, and the Ag nanoclusters are evenly attached on the surface of rGO and NiMoO4. The NiMoO4-Ag/rGO composite shows an excellent electrochemical performance and its specific capacitance (566.4 C g−1) is more than 2 times than that of NiMoO4 (212.9 C g−1) or NiMoO4-Ag (378.6 C g−1) electrode material at 1 A g−1. Moreover, the NiMoO4-Ag/rGO composite displays an excellent cycle stability, which can retain 90.5% of initial capacitance after 1000 cycles at 10 A g−1. Furthermore, the assembled NiMoO4-Ag/rGO//AC capacitor exhibits a high energy density of 40.98 Wh kg−1 at 800 W kg−1. Importantly, the hybrid capacitor still shows 73.3% of capacitance retention after 8000 cycles at 10 A g−1, which exhibits an excellent cyclic stability. When compared with NiMoO4[22], CoMoO4-NiMoO4[23] and CoMoO4-NiMoO4·xH2O[24] electrode materials for the application of supercapacitors, our NiMoO4-Ag/rGO composite shows better electrochemical performance. It can be contributed to the combination of NiMoO4 flakes and rGO sheets that greatly improve active sites for electrochemical redox reaction. Moreover, the introduction of Ag nanoparticles can effectively accelerate the charge transfer and enhance the specific capacitance of composite. Moreover, due to the 2D-2D interface coupling formed by rGO and NiMoO4 nanosheets, as well as the stable 3D hydrangea-like micro-architecture, the composite shows an enhanced cycling stability. Therefore, this work provides an effective strategy to design and construct stable electrode materials with high electrochemical activity for supercapacitors.
Section snippets
Materials
Ni(NO3)2·6H2O, Na2MoO4·H2O, AgNO3, Disodium ethylenediaminetetraacetic acid (EDTA-2Na), active carbon (AC), KOH and polytetrafluoroethylene (PTFE) were purchased from Sinopharm Chemical Reagent Co., Ltd (China). All reagents and solvents were of analytical grade and used as received.
Preparation
Graphite oxide (GO) was made of scaly graphite as raw material, and was prepared by modified Hummers method[25].
Microstructure characterizations
The preparation process of 3D hydrangea-like NiMoO4-Ag/rGO composite is illustrated in Fig. 1. Firstly, Ni2+ and MoO42- were controlled by EDTA2- to generate flake-like NiMoO4. NiMoO4 and GO sheets were assembled into a stable 3D hydrangea-like NiMoO4/rGO. Then, the Ag nanoparticles were anchored to the surface of NiMoO4/rGO and formed NiMoO4-Ag/rGO. The morphology and microstructure of NiMoO4-Ag/rGO composite were observed by FESEM. As shown in Fig. 2a and Fig. S1, NiMoO4 presents a 3D
Conclusion
In summary, a facile two-step hydrothermal method was utilized to prepare the unique 3D hydrangea-like NiMoO4-Ag/rGO composite which is applied as the high electrochemical activity and stability electrode materials for supercapacitors. 3D hydrangea-like micro-architecture and 2D-2D interface coupling formed by rGO and NiMoO4 nanosheets enhances the cycling stability of composite. Moreover, NiMoO4 flakes, rGO sheets and Ag nanoparticles can greatly improve the electrochemical activity of the
CRediT authorship contribution statement
Bingji Huang: Conceptualization, Methodology, Visualization, Data curation, Writing–original draft, Writing–review & editing, Investigation. Dachuan Yao: Conceptualization, Methodology, Visualization, Data curation. Jingjing Yuan: Data curation, Writing–original draft, Writing–review & editing. Yingrui Tao: Visualization, Data curation, Investigation. Yixuan Yin: Resources, Validation. Guangyu He: Conceptualization, Resources, Supervision. Haiqun Chen: Conceptualization, Resources, Supervision.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
The authors are grateful for the financial support from National Natural Science Foundation of China (grant number 22078028, 21978026), Changzhou Key Laboratory of Graphene-Based Materials for Environment and Safety (grant number CM20153006, CE20185043), PAPD of Jiangsu Higher Education Institution, and Postgraduate Research & Practice Innovation Program of Jiangsu Province (grant number SJCX20-0954, KYCX20-2564).
References (65)
- et al.
High performance NiMoO4 nanowires supported on carbon cloth as advanced electrodes for symmetric supercapacitors
Nano Energy
(2014) - et al.
Electrocatalytic properties of new spinel-type MMoO4 (M=Fe, Co and Ni) electrodes for oxygen evolution in alkaline solutions
Int. J. Hydrogen Energy
(2008) - et al.
Mesoporous NiMoO4 microspheres decorated by Ag quantum dots as cathode material for asymmetric supercapacitors: Enhanced interfacial conductivity and capacitive storage
Appl. Surf. Sci.
(2020) - et al.
Ultrathin mesoporous NiMoO4-modified MoO3 core/shell nanostructures: Enhanced capacitive storage and cycling performance for supercapacitors
Chem. Eng. J.
(2018) - et al.
Impact of process conditions on the electrochemical performances of NiMoO4 nanorods and activated carbon based asymmetric supercapacitor
Appl. Surf. Sci.
(2019) - et al.
Porous worm-like NiMoO4 coaxially decorated electrospun carbon nanofiber as binder-free electrodes for high performance supercapacitors and lithium-ion batteries
Appl. Surf. Sci.
(2018) - et al.
Manganese-doped nickel molybdate nanostructures for high-performance asymmetric supercapacitors
Chem. Eng. J.
(2019) - et al.
Rapid microwave-assisted synthesis of mesoporous NiMoO4 nanorod/reduced graphene oxide composites for high-performance supercapacitors
Electrochim. Acta
(2015) - et al.
Solid-state chemical fabrication of one-dimensional mesoporous beta-nickel molybdate nanorods as remarkable electrode material for supercapacitors
J. Colloid Interface Sci.
(2019) - et al.
Ultrasmall NiMoO4 robust nanoclusters-active carbon composite for high performance extrinsic pseudocapacitor
Electrochim. Acta
(2019)
Facile microwave-assisted green synthesis of Ag-ZnFe2O4@rGO nanocomposites for efficient removal of organic dyes under UV- and visible-light irradiation
Appl. Catal. B
Freestanding hierarchical nickel molybdate@reduced graphene oxide@nickel aluminum layered double hydroxides nanoarrays assembled from well-aligned uniform nanosheets as binder-free electrode materials for high performance supercapacitors
J. Colloid Interface Sci.
Nickel molybdate nanorods supported on three-dimensional, porous nickel film coated on copper wire as an advanced binder-free electrode for flexible wire-type asymmetric micro-supercapacitors with enhanced electrochemical performances
J. Colloid Interface Sci.
NiMoO4 nanowires supported on Ni/C nanosheets as high-performance cathode for stable aqueous rechargeable nickel-zinc battery
Chem. Eng. J.
Controlled synthesis of hierarchical α-nickel molybdate with enhanced solar-light-responsive photocatalytic activity: a comprehensive study on the kinetics and effect of operational factors
Ceram. Int.
Engineering Mo-O-C interface in MoS2@rGO via charge transfer boosts hydrogen evolution
Chem. Eng. J.
Enriched photoelectrocatalytic degradation and photoelectric performance of BiOI photoelectrode by coupling rGO
Appl. Catal.
Fabrication of ZnAl mixed metal-oxides/RGO nanohybrid composites with enhanced photocatalytic activity under visible light
Appl. Surf. Sci.
Novel urea assisted hydrothermal synthesis of hierarchical BiVO4/Bi2O2CO3 nanocomposites with enhanced visible-light photocatalytic activity
Appl. Catal. B
Heterogeneous activation of persulfate by NiFe2−xCoxO4-RGO for oxidative degradation of bisphenol A in water
Chem. Eng. J.
Microemulsion-mediated synthesis and characterization of monodispersed nickel molybdate nanocrystals
Ceram. Int.
Core-branched NiCo2S4@CoNi-LDH heterostructure as advanced electrode with superior energy storage performance
Chem. Eng. J.
2D/2D heterostructures of nickel molybdate and MXene with strong coupled synergistic effect towards enhanced supercapacitor performance
J. Power Sources
Effect of fluorine doping and sulfur vacancies of CuCo2S4 on its electrochemical performance in supercapacitors
Chem. Eng. J.
Transition metal based battery-type electrodes in hybrid supercapacitors: A review
Energy Stor. Mater.
Controllable growth of hierarchical NiCo2O4 nanowires and nanosheets on carbon fiber paper and their morphology-dependent pseudocapacitive performances
Electrochim. Acta
Carbon quantum dots for advanced electrocatalysis
J. Energ. Chem.
Advances in CoP electrocatalysts for water splitting
Mater. Today Energy
Two-dimensional titanium carbide (MXene)-wrapped sisal-Like NiCo2S4 as positive electrode for High-performance hybrid pouch-type asymmetric supercapacitor
Chem. Eng. J.
Preparation and performances of 3D hierarchical core-shell structural NiCo2S4@NiMoO4·xH2O nanoneedles for electrochemical energy storage
Electrochim. Acta
Rational design and construction of nickel molybdate nanohybrid composite for high-performance supercapattery
Appl. Surf. Sci.
Honeycomb-like NiMoO4 ultrathin nanosheet arrays for high-performance electrochemical energy storage
J. Mater. Chem. A
Cited by (33)
Disorder/order-heterophase VO<inf>2</inf> for enhanced lithium storage performance in lithium-ion capacitors
2024, Journal of Energy Storage