1. Introduction
1.1. supercapacitors
The electrochemical supercapacitors (ESs), also known as a supercapacitor or an ultracapacitor, has attracted considerable interest in both academia and industry because it has some distinct advantages such as higher power density induced by a fast charging/discharging rate (in seconds) and a long cycle life (4100 000 cycles) when compared to batteries and fuel cells. Depending on the charge storage mechanism, ESs can be briefly classified as electrochemical double-layer capacitors (EDLCs), pseudocapacitors and hybrid-capacitors [1]. Compared to both pseudocapacitors and hybrid-capacitors, EDLCs constitute the majority of currently available commercial ESs, mainly due to their technical maturity. In an evaluation of electrochemical energy devices, besides the cycle-life (or lifetime), both their energy density and power density are the two most important properties. The relationship between these two important properties can be expressed by the Ragone plot. Fig. 1.1 shows the Ragone plots for several typical electrochemical energy storage devices. It can be clearly seen from these Ragone plots that supercapacitors are currently located between the conventional dielectric capacitors and batteries/fuel cells. Despite the much lower energy density compared to the batteries/fuel cells, ESs can have much higher power densities. This makes them promising for applications in current stabilization when accessing intermittent renewable energy sources. In addition, ESs have also attracted considerable interest in a wide variety of applications requiring high power density, such as portable electronics, electric or hybrid electric vehicles, aircraft and smart grids.






1.2. Classification of ES
Basically, the ES is a special type of capacitor, which is different from the classical electrostatic capacitors (Fig. 1.2A). ESs can be distinguished in several ways such as the charge storage mechanism, the electrolyte, the electrode material and the cell structure. Depending on the charge storage mechanism, ESs can be classified into three categories: (1) Electric double-layer capacitors (EDLCs), where the capacitance is produced by the electrostatic charge separation at the interface between the electrode and the electrolyte (Fig. 1.2B). To maximize the charge storage capacity, the electrode materials are usually made from highly porous carbon materials. (2) Pseudocapacitors, which rely on fast and reversible faradaic redox reactions to store the charges (Fig. 1.2C). (3) Hybrid ESs, which refer to ones using both the electrical double-layer (EDL) and faradaic mechanisms to store charges [2].







1.3. Electrode materials
1.3.1. Carbon-based electrode materials
1.3.1.1. CNTs
The discovery of CNTs has significantly advanced the science and engineering of carbon materials. Carbon nanotubes, due to their unique pore structure, superior electrical properties, and good mechanical and thermal stability, have attracted a great deal of attention for supercapacitor electrode applications. CNTs can be categorized as single-walled carbon nanotubes (SWNTs) or multi-walled carbon nanotubes (MWNTs), both of which have been widely explored as energy storage electrode materials. CNTs are usually regarded as the choice of a high-power electrode material because of their good electrical conductivity and readily accessible surface area. Moreover, their high mechanical resilience and open tubular network make them a good support for active materials. The energy density is, however, a concern due to their relatively small specific surface area (generally 500 m2 g-1) as compared to ACs. Of greater importance is the difficulty in retaining the intrinsic properties of individual CNTs on a macroscopic scale and the high purity [3].
1.3.1.2. Graphene
Graphene is a one-atom-thick sheet of sp2-bonded carbon atoms in a honey comb crystallattice, which is the cutting- edge of materials science and condensed matter physics research. It is the thinnest known material in the world and conceptually a basic build block for constructing many other carbon materials [4]. It can be rolled into one-dimensional CNTs, and stacked into three-dimensional (3D) graphite. With the addition of pentagons it can be wrapped into a spherical fullerene. In one sense, it is the mother of all graphitic materials. In 2004, Geim and Novoselov reported their experimental investigation of the exfoliation, characterization and electronic properties of this two-dimensional (2D) carbon by repeatedly cleaving graphite with an adhesive tape. Theoretical work on this structure has being carried out for decades. Since 2004, much work has been related to the synthesis of graphene, because its availability is an important precondition for its use in research and development into possible applications.
1.3.2. Transition metal oxides and hydroxides
In general, metal oxides can provide higher energy density for ES than conventional
carbon materials and better electrochemical stability than polymer materials. They not only store energy like electrostatic carbon materials but also exhibit electrochemical faradaic reactions between electrode materials and ions within appropriate potential windows.The general requirements for metal oxides in ES applications are: (1) the oxide should be electronically conductive, (2) the metal can exist in two or more oxidation states that coexist over a continuous range with no phase changes involving irreversible modifications of a 3-dimensional structure. There are several different metal oxide materials used for electrode fabrication such as RuO2 [5], MnO2 [6], Fe3O4 [7], NiO [8], Ni(OH)2 [9], Co3O4 [10], V2O5 [11], CuO [12], Cu(OH)2 [13], and Cu2O [14].
1.3.4. Transition metal sulfides
During the long term investigation of high performance supercapacitors, many researches have been concentrated on transition metal oxides as pseudocapacitance electrode materials, because of high specific capacitance and energy density [15]. Also, considerable efforts have been taken to the development of graphene analogue layered transition metal chalcogenides as notable materials for pseudocapacitors [16, 17]. Recently, binary metal sulfides (RuS2, CuS, FeS2,VS2,VS4, NiS2 and CoS) have attracted great attention as a new class of promising electrode materials for energy storage applications. Distinct physicochemical and electronic properties of metal sulfides such as high electrical conductivity, good mechanical and thermal stability compared with metal oxides, and rich redox chemistry makes them as a candidate for supercapacitor applications [18-22].
1.3.5. Conducting polymers
Conductive polymers are polymers with highly p-conjugated polymeric chains. Typical conductive polymers (Fig. 1.3) include polyacetylene (PA, 3–1000 S cm-1), polyaniline (PANI, 0.01–5 S cm-1), polypyrrole (PPy, 0.3–100 S cm-1), polythiophene (PTh, 2–150 S cm-1), poly(phenylenevinylene) (PPV, 10-3–100 S cm-1), etc. The conductivity of neutral conjugated polymers is rather low, usually in the range of 10-10–10-5 S cm-1. But they could be tuned in a wide range up to 104 S cm-1 through chemical or electrochemical redox reactions, so-called ‘‘doping’’. The resulting conductivity highly depends on the dopants used as well as the level of doping. This unique feature endows conductive polymers the ability to act as insulators, semiconductors and conductors. Doping is a reversible process, which makes the backbone of conductive polymer positive (p-doping) or negative charge carriers (n-doping). Therefore, counter ions with opposite charges would be entrapped or released from the polymer matrix to maintain the charge neutrality of the polymers. In the past two decades, the CPs are extensively explored for supercapacitor application due to their reversible Faradaic redox nature, high charge density, and lower cost as compared with the expensive metal oxides.




However, the drawback of transition metal oxides/sulfides and conducting polymers is instability during the continuous, which lead to mechanical degradation of the electrode material and decaying of the electrochemical performance. In order to solve this problem,
many researchers have suggested that the combination of pseudocapacitance materials and carbon nanostructures can improve the mechanical and electrical properties of their corresponding composites.
1.4. Water splitting
Water electrolysis is composed of two half-reactions that are H2 evolution reaction (HER) and O2 evolution reaction (OER) [23]. Since the HER and OER reactions are kinetically sluggish, two types of catalysts are required to reduce the large overpotential to generate H2 and O2. Generally, the state-of-the-art catalysts are considered the noble metal Platinum (Pt) based materials for the HER under acidic conditions, while Ruthenium (Ru) and Iridium (Ir) based materials are regarded as efficient electrocatalysts for the OER under basic conditions. Nevertheless, due to limited availability and exorbitant price, they are not suitable to be used in large-scale and widespread practical applications. Therefore, the development of economical, easily scalable, and earth-abundant catalysts for enhancing the electrocatalytic activity and minimizing the overpotential is indispensable. In recent years, significant advances have been seen in noble‐metal‐free electrocatalysts, such as transition metal phosphides, chalcogenides, nitrides, and oxides [24-28]. These catalysts not only possess good stability and catalytic activity toward OER in alkaline conditions but also exhibit remarkable catalytic performance for HER in an acidic solution due to their high electrochemical stability in the operating potential window of the HER [29, 30]. Besides, it is well known that nanostructured catalysts can increase accessible active sites and the efficient contact area between electrolyte ions and electroactive materials. Hence, the development of nanostructured catalysts is an encouraging approach to improve electrocatalytic performance of both OER and HER.

2. Successive Ionic Layer Deposition method
Successive Ionic Layer Deposition (SILD) method, also called the Successive Ionic Layer Adsorption and Reaction (SILAR) is based on multiple and successive treatment of
substrate by solutions of reagents which enter into reaction at its surface and form a layer of poorly soluble substance that makes possible to deposit nanolayers of controlled thickness
on the surface of parts of any shape, which are exactly the requirements to the methods of synthesis of the nanolayers on the surface of electrodes for supercapacitors or batteries and
to be used previously for the synthesis of nanolayers of oxides, fuorides, and also noble metal nanoparticles [31-33].

Fig. 1.4. Schematic illustration of SILAR method.
Based on the above, significant attention has been devoted to investigation hybrids with special morphology by the novel methods for improvement the capacitive performance of supercapacitors and catalytic performance of water splitting. However, new methods for preparing new hybrids are still a big challenge. So this work would be dictated to developing the new hybrids with special morphology by novel technology for energy conversion/storage systems.
3. Review on literatures
Many efforts have been devoted to improve the electrochemical performance of the supercapacitors and Fuel cells. In order to achieve this demand, nanostructured materials received enormous interests in energy conversion and storage systems. Nanostructured materials provide more active sites and more efficient diffusion pathways for both electrons and ions, which cause improved electrochemical performance. Recently, nanostructured transition metal oxides and sulfides have emerged as the most prominent candidates for supercapacitors and fuel cells, because of outstanding properties such as high redox activity and stability. Therefore, construction of nanostructures is a desirable approach to improve the electrochemical performance of energy conversion and storage systems. Up to now, various transition metal oxides and sulfides have been used in supercapacitors and water splitting. For example, Fe3O4 thin film was successfully prepared by hydrothermal process and showed specific capacitance of 118.2 F g-1 at 6 mA. Also, the as-fabricated electrode material exhibited capacitance retention of 88.75% after 500 cycles [34]. However, pseudocapacitors often suffer from poor cyclability and rate capability, which limit their further applications due to structural destructions and created limitations in redox processes by the rate of mass diffusion and electron transfer. Combination of these materials with carbon-based nanostructures is an effective way to overcome this problem. For instance, P. Swain et al. [35] prepared Fe3O4-RGO by a one-step chemical reduction method. The maximum specific capacitance was achieved 416 F g-1 with capacitance retention of 88.57% at a current density of 5 Ag−1 over 1000 cycles. In one of the latest reports, hybrid composite Fe3O4/MXene/RGO was fabricated by a simple chemical process [36]. This hybrid displayed specific capacitance of 32 F g-1 at a current density of 0.2 A g-1 in 1 M Na2SO4 electrolyte. Yang et al.[37] prepared Ni-doped MnO2 nano-array on carbon cloth by hydrothermal process. The doping of metallic nickel and the unique nano-array structure expanded the operating voltage window of the electrode and the area specific capacitance was up to 1398.8 mF cm-2. Maiyalagan et al [38] synthesized α-Fe2O3/MnO2 nanocomposites by hydrothermal process. The α-Fe2O3/MnO2 exhibited a high specific capacity of 216 Fg-1 at a current density of 0.5 Ag-1, energy density of 7.5121Wh kg−1 at power density of 0.118 kW kg-1. Weng at al. [39] prepared MnO2@MXene/CNT by a facile hydrothermal process. The MnO2@MXene/CNTF electrode exhibited a high specific capacitance of 181.8 F g-1 at 1 A g-1 and a capacitance retention of 91% after 5000 charge-discharge cycles. Chai et al prepared phosphorous doped Fe3O4 as efficient electrocatalyst for HER with low overpotential of 138 mV at 100 mA cm-2 [40]. CoxFe3-xO4 film was synthesized by one-step electrodeposition method. The polycrystalline CoxFe3-xO4 film exhibited the high catalytic activity with an overpotential of ∼0.42 V at a current density of 10 mA cm−2 for OER [41]. Spinel type Fe3O4 polyhedron was prepared on Ni foam by hydrothermal process and used as efficient catalyst for OER [42]. Niu et al [43] prepared Co-doped MnO2 catalyst for OER activity. This catalyst showed high catalytic activity with an overpotential of 250 mV at a current density of 10 mA cm−2 in 1.0 M KOH solution. Vanadium oxysulfide/cobalt-cobalt sulfonitride (VOS/Co-CoSN) was prepared by electrodeposition method and used as efficient electrocatalyst for OER and HER activity. The binder free VOS-300/Co-CoSN electrode showed significant improvement in catalytic activity towards both OER (Tafel slope of 0.201 V dec−1 with overpotential of 0.34 V @100 A m−2 current density in 1.0 M KOH media) and HER (Tafel slope of 0.048 V dec−1 with overpotential of 0.18 V@100 A m−2 current density in 0.5 M H2SO4 solution) [44].
Prof. V. Tolstoy is the head of the scientific group “Programmable layer-by-layer synthesis of hybrid inorganic and organic materials”. Research topics include the development of new priority routes and methods for the synthesis of nanomaterials. One of these methods is the SILD method, independently proposed in 1984, which has now been widely used in the practice of many laboratories. This method is used to synthesize a wide range of nanomaterials, including active elements of gas and electrochemical sensors, protective coatings of metals, electrode materials for hybrid supercapacitor batteries and electrolyzers, sorbents and catalysts for the oxidation of a number of organic compounds, etc. On the topic of this project, dedicated to the creation of new electrodes for supercapacitors, selected articles were previously published:
1. Tolstoy, V.P., Lobinsky, A.A., Kaneva, M.V. Features of inorganic nanocrystals formation in conditions of successive ionic layers deposition in water solutions and the Co(II)Co(III) 2D layered double hydroxide synthesis (2019) Journal of Molecular Liquids, 282, pp. 32-38.
2. Lobinsky, A.A., Tolstoy, V.P. Synthesis of 2D Zn-Co LDH nanosheets by a successive ionic layer deposition method as a material for electrodes of high-performance alkaline battery-supercapacitor hybrid devices (2018) RSC Advances, 8 (52), pp. 29607-29612.
Dr. A. Esfandiar is the head of the Nano Scale Physics Lab Sharif University of Technology. This Lab in physics department of Sharif University of Technology (SUT), as an experimental condensed matter physics research laboratory, explores new ways to understand the physics behind of the interesting phenomena in new materials and low dimensions. It is focused on science and technology at the nanoscale, connecting the novel properties of nanomaterials to develop the scientific boundaries in fabrication of new devices for different application fields such as Energy harvesting, chemical sensing, and water treatment. We study new nanostructures mostly 2D materials, for a wide range of applications in multi-disciplinary domains from Physics and Chemistry to Electrical Engineering and biotechnology. Dr. A. Esfandiar articles have been published in highly cited international scientific journals including Nature (538, p. 222, 2016; 558, p. 420, 2018), Nature Communication (8: 15215, 2017), and Science (360, 6395, p. 1339, 2018; 358, p. 219, 2017).
The Lab has a large scientific background on the topic of the grant application. The following articles have previously been published on this topic:
1. Asen, P., & Esfandiar, A. (2021). Facile synthesis of highly efficient bifunctional electrocatalyst by vanadium oxysulfide spheres on cobalt-cobalt sulfonitride nanosheets for oxygen and hydrogen evolution reaction. Electrochimica Acta, 138948.
2. Rastgoo-Deylami, M., & Esfandiar, A. (2021). High Energy Aqueous Rechargeable Nickel–Zinc Battery Employing Hierarchical NiV-LDH Nanosheet-Built Microspheres on Reduced Graphene Oxide. ACS Applied Energy Materials, 4(3), 2377-2387.
Information on envisaged synergies between SPbU and SU
During the implementation of this project, the potential of the scientific group of prof. V.Tolstoy on the synthesis of new multilayers of oxyhydroxides in wide range of materials from number of transition metals and carbon nanostrials from one side and the background in Dr. A. Esfandiar's lab to study of two dimensional materials and their electrochemical properties, provide a worthy benchmark to trigger high quality research. Design and preparation of new materials to be hybridize as scrolled structures promises novel candidates to use inner and outer sides of nanomaterials with more accessible surface area. As a result of the project, in addition to publication of two or more prestigious research papers in international scientific journals, knowledge transferring, synergic collaborations and cooperation can be boosted between Russian-Iranian researchers during this project and for future joint projects.
After the publication of joint articles, it is planned to make a general proposal for participation in one of the competitions of scientific projects. For example, in the competition of the Russian Science Foundation on the topic of Russian-Iranian cooperation.
References

[1] P. Simon, T. Brousse, F. Favier, Electrochemical Double-Layer Capacitors (EDLC), Supercapacitors Based on Carbon or Pseudocapacitive Materials, John Wiley & Sons, Inc.2017, pp. 1-25.
[2] C. Zhong, Y. Deng, W. Hu, J. Qiao, L. Zhang, J. Zhang, A review of electrolyte materials and compositions for electrochemical supercapacitors, Chemical Society Reviews, 44 (2015) 7484-7539.
[3] K.H. An, W.S. Kim, Y.S. Park, Y.C. Choi, S.M. Lee, D.C. Chung, D.J. Bae, S.C. Lim, Y.H. Lee, Supercapacitors using single‐walled carbon nanotube electrodes, Advanced Materials, 13 (2001) 497-500.
[4] A.K. Geim, K.S. Novoselov, The rise of graphene, Nanoscience and Technology: A Collection of Reviews from Nature Journals, World Scientific2010, pp. 11-19.
[5] Z.S. Wu, D.W. Wang, W. Ren, J. Zhao, G. Zhou, F. Li, H.M. Cheng, Anchoring hydrous RuO2 on graphene sheets for high‐performance electrochemical capacitors, Advanced Functional Materials, 20 (2010) 3595-3602.
[6] J. Yan, Z. Fan, T. Wei, J. Cheng, B. Shao, K. Wang, L. Song, M. Zhang, Carbon nanotube/MnO2 composites synthesized by microwave-assisted method for supercapacitors with high power and energy densities, Journal of Power Sources, 194 (2009) 1202-1207.
[7] B. Hu, Y. Wang, X. Shang, K. Xu, J. Yang, M. Huang, J. Liu, Structure-tunable Mn3O4-Fe3O4@ C hybrids for high-performance supercapacitor, Journal of Colloid and Interface Science, 581 (2021) 66-75.
[8] R. Kumar, S.M. Youssry, H.M. Soe, M.M. Abdel-Galeil, G. Kawamura, A. Matsuda, Honeycomb-like open-edged reduced-graphene-oxide-enclosed transition metal oxides (NiO/Co3O4) as improved electrode materials for high-performance supercapacitor, Journal of Energy Storage, 30 (2020) 101539.
[9] J. Li, Y. Liu, W. Cao, N. Chen, Rapid in situ growth of β-Ni (OH) 2 nanosheet arrays on nickel foam as an integrated electrode for supercapacitors exhibiting high energy density, Dalton Transactions, 49 (2020) 4956-4966.
[10] M. Qorbani, T.-c. Chou, Y.-H. Lee, S. Samireddi, N. Naseri, A. Ganguly, A. Esfandiar, C.-H. Wang, L.-C. Chen, K.-H. Chen, A.Z. Moshfegh, Multi-porous Co3O4 nanoflakes @ sponge-like few-layer partially reduced graphene oxide hybrids: towards highly stable asymmetric supercapacitors, Journal of Materials Chemistry A, 5 (2017) 12569-12577.
[11] A. Ghosh, E.J. Ra, M. Jin, H.-K. Jeong, T.H. Kim, C. Biswas, Y.H. Lee, High Pseudocapacitance from Ultrathin V2O5 Films Electrodeposited on Self-Standing Carbon-Nanofiber Paper, Advanced Functional Materials, 21 (2011) 2541-2547.
[12] A. Esfandiar, M. Qorbani, I. Shown, B. Ojaghi Dogahe, A stable and high-energy hybrid supercapacitor using porous Cu2O–Cu1.8S nanowire arrays, Journal of Materials Chemistry A, 8 (2020) 1920-1928.
[13] S.K. Shinde, D.P. Dubal, G.S. Ghodake, D.Y. Kim, V.J. Fulari, Nanoflower-like CuO/Cu(OH)2 hybrid thin films: Synthesis and electrochemical supercapacitive properties, Journal of Electroanalytical Chemistry, 732 (2014) 80-85.
[14] K. Wang, X. Dong, C. Zhao, X. Qian, Y. Xu, Facile synthesis of Cu2O/CuO/RGO nanocomposite and its superior cyclability in supercapacitor, Electrochimica Acta, 152 (2015) 433-442.
[15] D. Szymanska, I.A. Rutkowska, L. Adamczyk, S. Zoladek, P.J. Kulesza, Effective charge propagation and storage in hybrid films of tungsten oxide and poly(3,4-ethylenedioxythiophene), Journal of Solid State Electrochemistry, 14 (2010) 2049-2056.
[16] K.-J. Huang, J.-Z. Zhang, Y. Fan, Preparation of layered MoSe2 nanosheets on Ni-foam substrate with enhanced supercapacitor performance, Materials Letters, 152 (2015) 244-247.
[17] K. Krishnamoorthy, P. Pazhamalai, S. Sahoo, S.-J. Kim, Titanium carbide sheet based high performance wire type solid state supercapacitors, Journal of Materials Chemistry A, 5 (2017) 5726-5736.
[18] Y. Wang, F. Liu, Y. Ji, M. Yang, W. Liu, W. Wang, Q. Sun, Z. Zhang, X. Zhao, X. Liu, Controllable synthesis of various kinds of copper sulfides (CuS, Cu7S4, Cu9S5) for high-performance supercapacitors, Dalton Transactions, 44 (2015) 10431-10437.
[19] J. Shi, X. Li, G. He, L. Zhang, M. Li, Electrodeposition of high-capacitance 3D CoS/graphene nanosheets on nickel foam for high-performance aqueous asymmetric supercapacitors, Journal of Materials Chemistry A, 3 (2015) 20619-20626.
[20] Y. Zhou, Y. Li, J. Yang, J. Tian, H. Xu, J. Yang, W. Fan, Conductive Polymer-Coated VS4 Submicrospheres As Advanced Electrode Materials in Lithium-Ion Batteries, ACS Applied Materials & Interfaces, 8 (2016) 18797-18805.
[21] T.M. Masikhwa, F. Barzegar, J.K. Dangbegnon, A. Bello, M.J. Madito, D. Momodu, N. Manyala, Asymmetric supercapacitor based on VS2 nanosheets and activated carbon materials, RSC Advances, 6 (2016) 38990-39000.
[22] K. Krishnamoorthy, P. Pazhamalai, S.J. Kim, Ruthenium sulfide nanoparticles as a new pseudocapacitive material for supercapacitor, Electrochimica Acta, 227 (2017) 85-94.
[23] D.-S. Mousavi, P. Asen, S. Shahrokhian, A. Irajizad, Three-dimensional hybrid of iron–titanium mixed oxide/nitrogen-doped graphene on Ni foam as a superior electrocatalyst for oxygen evolution reaction, Journal of colloid and interface science, 563 (2020) 241-251.
[24] R. Boppella, J. Park, H. Lee, G. Jang, J. Moon, Hierarchically Structured Bifunctional Electrocatalysts of Stacked Core–Shell CoS1− xPx Heterostructure Nanosheets for Overall Water Splitting, Small Methods, (2020) 2000043.
[25] X.-Y. Zhang, Y.-R. Zhu, Y. Chen, S.-Y. Dou, X.-Y. Chen, B. Dong, B.-Y. Guo, D.-P. Liu, C.-G. Liu, Y.-M. Chai, Hydrogen evolution under large-current-density based on fluorine-doped cobalt-iron phosphides, Chemical Engineering Journal, 399 (2020) 125831.
[26] B. Dong, J.-Y. Xie, N. Wang, W.-K. Gao, Y. Ma, T.-S. Chen, X.-T. Yan, Q.-Z. Li, Y.-L. Zhou, Y.-M. Chai, Zinc ion induced three-dimensional Co9S8 nano-neuron network for efficient hydrogen evolution, Renewable Energy, 157 (2020) 415-423.
[27] B.-Y. Guo, X.-Y. Zhang, X. Ma, T.-S. Chen, Y. Chen, M.-L. Wen, J.-F. Qin, J. Nan, Y.-M. Chai, B. Dong, RuO2/Co3O4 Nanocubes based on Ru ions impregnation into prussian blue precursor for oxygen evolution, International Journal of Hydrogen Energy, 45 (2020) 9575-9582.
[28] J.-Y. Xie, R.-Y. Fan, J.-Y. Fu, Y.-N. Zhen, M.-X. Li, H.-J. Liu, Y. Ma, F.-L. Wang, Y.-M. Chai, B. Dong, Double doping of V and F on Co3O4 nanoneedles as efficient electrocatalyst for oxygen evolution, International Journal of Hydrogen Energy, 46 (2021) 19962-19970.
[29] C. Tang, Q. Zhang, J. Wu, H. Chen, L. Chen, C.M. Li, Ultrathin-Nanosheets-Composed CoSP Nanobrushes as an All-pH Highly Efficient Catalyst toward Hydrogen Evolution, ACS Sustainable Chemistry & Engineering, 6 (2018) 15618-15623.
[30] H.J. Song, H. Yoon, B. Ju, G.H. Lee, D.W. Kim, 3D Architectures of Quaternary Co‐Ni‐S‐P/Graphene Hybrids as Highly Active and Stable Bifunctional Electrocatalysts for Overall Water Splitting, Advanced Energy Materials, 8 (2018) 1802319.
[31] V. Tolstoy, L. Gulina, G. Korotchenkov, V. Brynsari, Synthesis of nanolayers hydroxo-(SnxOyHz) and heteropoly-(HxPWyOz) compounds of hybrid-type on silica surfaces by successive ionic layer deposition method, Applied surface science, 221 (2004) 197-202.
[32] V. Tolstoy, B. Altangerel, A new “fluoride” synthesis route for successive ionic layer deposition of the ZnxZr (OH)yFz· nH2O nanolayers, Materials Letters, 61 (2007) 123-125.
[33] G. Korotcenkov, L.B. Gulina, B. Cho, V. Brinzari, V.P. Tolstoy, Synthesis by successive ionic layer deposition (SILD) methodology and characterization of gold nanoclusters on the surface of tin and indium oxide films, Pure and Applied Chemistry, 86 (2014) 801-817.
[34] J. Chen, K. Huang, S. Liu, Hydrothermal preparation of octadecahedron Fe3O4 thin film for use in an electrochemical supercapacitor, Electrochimica Acta, 55 (2009) 1-5.
[35] B.P. Swain at al., Investigation of chemical bonding and supercapacitivity properties of Fe3O4-rGO nanocomposites for supercapacitor applications, Diamond and Related Materials, 104 (2020) 107756.
[36] T. Arun, A. Mohanty, A. Rosenkranz, B. Wang, J. Yu, M.J. Morel, R. Udayabhaskar, S.A. Hevia, A. Akbari-Fakhrabadi, R. Mangalaraja, Role of electrolytes on the electrochemical characteristics of Fe3O4/MXene/RGO composites for supercapacitor applications, Electrochimica Acta, 367 (2021) 137473.
[37] R. Zhong, M. Xu, N. Fu, R. Liu, A.a. Zhou, X. Wang, Z. Yang, A flexible high-performance symmetric quasi-solid supercapacitor based on Ni-doped MnO2 nano-array @ carbon cloth, Electrochimica Acta, 348 (2020) 136209.
[38] M. Racik K, A. Manikandan, M. Mahendiran, J. Madhavan, M. Victor Antony Raj, M.G. Mohamed, T. Maiyalagan, Hydrothermal synthesis and characterization studies of α-Fe2O3/MnO2 nanocomposites for energy storage supercapacitor application, Ceramics International, 46 (2020) 6222-6233.
[39] Q. Liu, J. Yang, X. Luo, Y. Miao, Y. Zhang, W. Xu, L. Yang, Y. Liang, W. Weng, M. Zhu, Fabrication of a fibrous MnO2@MXene/CNT electrode for high-performance flexible supercapacitor, Ceramics International, 46 (2020) 11874-11881.
[40] J. Zhang, X. Shang, H. Ren, J. Chi, H. Fu, B. Dong, C. Liu, Y. Chai, Modulation of inverse spinel Fe3O4 by phosphorus doping as an industrially promising electrocatalyst for hydrogen evolution, Advanced Materials, 31 (2019) 1905107.
[41] S. Han, S. Liu, S. Yin, L. Chen, Z. He, Electrodeposited Co-Doped Fe3O4 Thin Films as Efficient Catalysts for the Oxygen Evolution Reaction, Electrochimica Acta, 210 (2016) 942-949.
[42] A.A. Pawar, H.A. Bandal, H. Kim, Spinel type Fe3O4 polyhedron supported on nickel foam as an electrocatalyst for water oxidation reaction, Journal of Alloys and Compounds, 863 (2021) 158742.
[43] J. Jia, L. Li, X. Lian, M. Wu, F. Zheng, L. Song, G. Hu, H. Niu, A mild reduction of Co-doped MnO2 to create abundant oxygen vacancies and active sites for enhanced oxygen evolution reaction, Nanoscale, 13 (2021) 11120-11127.
[44] P. Asen, A. Esfandiar, Facile synthesis of highly efficient bifunctional electrocatalyst by vanadium oxysulfide spheres on cobalt-cobalt sulfonitride nanosheets for oxygen and hydrogen evolution reaction, Electrochimica Acta, 391 (2021) 138948.