An Investigation into the Influence of Graphene Content on Achieving a High-Performance TiO2-Graphene Nanocomposite Supercapacitor

This study presents the synthesis of TiO2-graphene nanocomposites with varying mass ratios of graphene (2.5, 5, 10, 20 wt. %) using a facile and cost-effective hydrothermal approach. By integrating TiO2 nanoparticles with graphene, a nanomaterial characterized by a two-dimensional structure, unique electrical conductivity and high specific surface area, the resulting hybrid material shows promise for application in supercapacitors. The nanocomposite specimens were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman microscopy, field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Additionally, supercapacitive properties were investigated using a three-electrode setup by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) tests. Notably, the TiO2-20 wt. % rGO nanocomposite exhibited the highest specific capacitance of 624 F/g at 2 A/g, showcasing superior electrochemical performance. This specimen indicated a high rate capability and cyclic stability (93 % retention after 2000 cycles). Its remarkable energy density and power density of this sample designate it as a strong contender for practical supercapacitor applications.

Synthesis and Electrochemical Characterization of ZnMoS4 Nanorods on Nickel Foam Substrate for Advanced Hybrid Supercapacitor Applications

A single-step hydrothermal method was utilized to grow ZnMoS4 (ZMS) nanorods uniformly. Initially, [MoS4]2- and Zn2+ ions interacted to create active nucleation centers, which then led to the formation of primary particles. These particles then underwent spontaneous aggregation and self-assembly on the nickel foam (NF) substrate, which served as a superior 3D interconnecting network template. This aggregation occurred nearly perpendicular to the NF and promoted the uniform growth of ZMS nanorods. The nanorods structure ensures efficient and rapid electrolyte accessibility and ion diffusion, resulting in an increased specific capacitance (Cs) of 2,116 Fg1- (846.4 C g-1) at 1 A g-1 and maintaining about 90% of their capacitance after 10,000 cycles of galvanic charge-discharge (GCD). In a hybrid supercapacitor configuration, ZMS@NF//AC@NF achieved a peak specific power of 7.2 kW.kg-1 and a specific energy of 40.3 Wh.kg-1. Remarkably, it preserved 93% of its initial capacitance after more than 20,000 cycles. These findings affirm the potential of binder-free ZMS nanorods as effective positive electrodes in advanced hybrid supercapacitors.

Recent progress in metal oxide-based electrode materials for safe and sustainable variants of supercapacitors

A significant amount of energy can be produced using renewable energy sources; however, storing massive amounts of energy poses a substantial obstacle to energy production. Economic crisis has led to rapid developments in electrochemical (EC) energy storage devices (EESDs), especially rechargeable batteries, fuel cells, and supercapacitors (SCs), which are effective for energy storage systems. Researchers have lately suggested that among the various EESDs, the SC is an effective alternate for energy storage due to the presence of the following characteristics: SCs offer high-power density (PD), improvable energy density (ED), fast charging/discharging, and good cyclic stability. This review highlighted and analyzed the concepts of supercapacitors and types of supercapacitors on the basis of electrode materials, highlighted the several feasible synthesis processes for preparation of metal oxide (MO) nanoparticles, and discussed the morphological effects of MOs on the electrochemical performance of the devices. In this review, we primarily focus on pseudo-capacitors for SCs, which mainly contain MOs and their composite materials, and also highlight their future possibilities as a useful application of MO-based materials in supercapacitors. The novelty of MO's electrode materials is primarily due to the presence of synergistic effects in the hybrid materials, rich redox activity, excellent conductivity, and chemical stability, making them excellent for SC applications.

Nanostructured TiO2 Arrays for Energy Storage

Because of their extensive specific surface area, excellent charge transfer rate, superior chemical stability, low cost, and Earth abundance, nanostructured titanium dioxide (TiO₂) arrays have been thoroughly explored during the past few decades. The synthesis methods for TiO₂ nanoarrays, which mainly include hydrothermal/solvothermal processes, vapor-based approaches, templated growth, and top-down fabrication techniques, are summarized, and the mechanisms are also discussed. In order to improve their electrochemical performance, several attempts have been conducted to produce TiO₂ nanoarrays with morphologies and sizes that show tremendous promise for energy storage. This paper provides an overview of current developments in the research of TiO₂ nanostructured arrays. Initially, the morphological engineering of TiO₂ materials is discussed, with an emphasis on the various synthetic techniques and associated chemical and physical characteristics. We then give a brief overview of the most recent uses of TiO₂ nanoarrays in the manufacture of batteries and supercapacitors. This paper also highlights the emerging tendencies and difficulties of TiO₂ nanoarrays in different applications.

Nanocomposite Electrode of Titanium Dioxide Nanoribbons and Multiwalled Carbon Nanotubes for Energy Storage

TiO₂ is one of the most investigated materials due to its abundance, lack of toxicity, high faradaic capacitance, and high chemical and physical stability; however, its potential use in energy storage devices is constrained by its high internal resistance and weak van der Waals interaction between the particles. Carbon nanotubes are especially well suited for solving these issues due to their strong mechanical strength, superior electrical conductivity, high electron mobilities, excellent chemical and thermal stability, and enormous specific nanoporous surface. The hydrothermal approach was followed by chemical vapor deposition to produce a network composite of titanium dioxide nanoribbons (TNRs) and multi-walled carbon nanotubes (MWCNTs). The nanocomposite was characterized using a variety of methods. One phase of TiO₂-B nanoribbons has porous pits on its surface, and MWCNTs are grown in these pits to produce a network-like structure in the nanocomposite. With a two-electrode supercapacitor configuration, the TNR/CNT gave a gravimetric capacitance of 33.33 F g^-1, which was enhanced to 68.18 F g^-1 in a redox-active electrolyte containing hydroquinone (HQ). Additionally, the areal capacitance per footprint was increased from 80 mF cm^-2 in H₂SO₄ to 163.63 mF cm^-2 in H₂SO₄/HQ. The TNR/CNT supercapacitor has superior cyclic stability than the previously reported TiO₂-based electrodes, with 97.5% capacitance retention after 5000 cycles. Based on these results, it looks like the TNR/CNT supercapacitor could provide portable electronic power supplies with new ways to work in the future.

Wet-Chemical Synthesis of TiO2/PVDF Membrane for Energy Applications

To satisfy the ever-increasing energy demands, it is of the utmost importance to develop electrochemical materials capable of producing and storing energy in a highly efficient manner. Titanium dioxide (TiO₂) has recently emerged as a promising choice in this field due to its non-toxicity, low cost, and eco-friendliness, in addition to its porosity, large surface area, good mechanical strength, and remarkable transport properties. Here, we present titanium dioxide nanoplates/polyvinylidene fluoride (TiO₂/PVDF) membranes prepared by a straightforward hydrothermal strategy and vacuum filtration process. The as-synthesized TiO₂/PVDF membrane was applied for energy storage applications. The fabricated TiO₂/PVDF membrane served as the negative electrode for supercapacitors (SCs). The electrochemical properties of a TiO₂/PVDF membrane were explored in an aqueous 6 M KOH electrolyte that exhibited good energy storage performance. Precisely, the TiO₂/PVDF membrane delivered a high specific capacitance of 283.74 F/g at 1 A/g and maintained capacitance retention of 91% after 8000 cycles. Thanks to the synergistic effect of TiO₂ and PVDF, the TiO₂/PVDF membrane provided superior electrochemical performance as an electrode for a supercapacitor. These superior properties will likely be used in next-generation energy storage technologies.

A New CuSe-TiO2-GO Ternary Nanocomposite: Realizing a High Capacitance and Voltage for an Advanced Hybrid Supercapacitor

A high capacitance and widened voltage frames for an aqueous supercapacitor system are challenging to realize simultaneously in an aqueous medium. The severe water splitting seriously restricts the narrow voltage of the aqueous electrolyte beyond 2 V. To overcome this limitation, herein, we proposed the facile wet-chemical synthesis of a new CuSe-TiO₂-GO ternary nanocomposite for hybrid supercapacitors, thus boosting the specific energy up to some maximum extent. The capacitive charge storage mechanism of the CuSe-TiO₂-GO ternary nanocomposite electrode was tested in an aqueous solution with 3 M KOH as the electrolyte in a three-cell mode assembly. The voltammogram analysis manifests good reversibility and a remarkable capacitive response at various currents and sweep rates, with a durable rate capability. At the same time, the discharge/charge platforms realize the most significant capacitance and a capacity of 920 F/g (153 mAh/g), supported by the impedance analysis with minimal resistances, ensuring the supply of electrolyte ion diffusion to the active host electrode interface. The built 2 V CuSe-TiO₂-GO||AC-GO||KOH hybrid supercapacitor accomplished a significant capacitance of 175 F/g, high specific energy of 36 Wh/kg, superior specific power of 4781 W/kg, and extraordinary stability of 91.3% retention relative to the stable cycling performance. These merits pave a new way to build other ternary nanocomposites to achieve superior performance for energy storage devices.

Optically Controlled TiO2-Embedded Supercapacitors: The Effects of Colloidal Size, Light Wavelength, and Intensity on the Cells' Performance

Optically controlled supercapacitors (S-C) could be of interest to the sensor community, as well as set the stage for novel optoelectronic charging devices. Here, structures constructed of two parallel transparent current collectors (indium-tin-oxide, ITO films on glass substrates) were considered. Active-carbon (A-C) films were used as electrodes. Two sets of electrodes were used: as-is electrodes that were used as the reference and electrodes that were embedded with submicron- or micron-sized titanium oxide (TiO2) colloids. While immersed in a 1 M Na2SO4, the electrodes exhibited minimal thermal effects (<3 °C) throughout the course of experiments). The optically induced capacitance increase for TiO2-embedded S-C was large of the order of 30%, whereas S-C without the TiO2 colloids exhibited minimal optically related effects (<3%). Spectrally, the blue spectral band had a relatively larger impact on the light-induced effects. A lingering polarization effect that increased the cell capacitance in the dark after prolonged light exposure is noted; that effect occurred without an indication of a chemical reaction.

In situ synthesis of nanostructured Fe3O4@TiO2 composite grown on activated carbon cloth as a binder-free electrode for high performance supercapacitors

Transition metal oxide (TMO) nanomaterials with regular morphology have received widening research attention as electrode materials due to their improved electrochemical characteristics. In this study we present the successful fabrication of an Fe₃O₄/TiO₂ nanocomposite grown on a carbon cloth (Fe₃O₄/TiO₂@C) used as a high-efficiency electrochemical supercapacitor electrode. Flexible electrodes are directly used for asymmetric supercapacitors without any binder. The increased specific surface area of the TiO₂ nanorod arrays provides sufficient adsorption sites for Fe₃O₄ nanoparticles. An asymmetric supercapacitor composed of Fe₃O₄/TiO₂@C is tested in 1 M Na₂SO₃ electrolyte, and the synergistic effects of fast reversible Faraday reaction on the Fe₃O₄/TiO₂ surface and the highly conductive network formed by TiO₂@C help the electrode to achieve a high areal capacitance of 304.1 mF cm⁻² at a current density of 1 mA cm⁻² and excellent cycling stability with 90.7% capacitance retention at 5 mA cm⁻² after 10 000 cycles. As a result, novel synthesis of a binder-free Fe₃O₄/TiO₂@C electrode provides a feasible approach for developing competitive candidates in supercapacitor applications.

Transition metal oxide (TMO) nanomaterials with regular morphology have received widening research attention as electrode materials due to their improved electrochemical characteristics.

Three-Dimensional Hierarchical Core/shell Electrodes Using Highly Conformal TiO2 and Co3O4 Thin Films for High-Performance Supercapattery Devices

The rational design and development of novel electrode materials with promising nanostructures is an effective technique to improve their supercapacitive performance. This work presents high-performance core/shell electrodes based on three-dimensional hierarchical nanostructures coated with conformal thin transition-metal oxide layers using atomic layer deposition (ALD). This effective interface engineering creates disorder in the electronic structure and coordination environment at the interface of the heteronanostructure, which provides many more reaction sites and rapid ion diffusion. At 3 A g^-1, the positive CuCo₂O₄/Ni₄Mo/MoO₂@ALD-Co₃O₄ electrode introduced here exhibits a specific capacity of 1029.1 C g^-1, and the fabricated negative Fe₃O₄@ALD-TiO₂ electrode significantly outperforms conventional carbon-based electrodes, with a maximum specific capacity of 372.6 C g^-1. The supercapattery cell assembled from these two interface- and surface-tailored electrodes exhibits a very high energy density of 110.4 W h kg^-1 with exceptional capacity retention over 20,000 cycles, demonstrating the immense potential of ALD for the next generation of supercapacitors.

Ultrasound-assisted synthesis of unzipped multiwalled carbon nanotubes/titanium dioxide nanocomposite as a promising next-generation energy storage material

Carbon-based systems have been discussed as prospective alternatives for conventional metal-based catalysts over the past decade. These studies were motivated by the abundance, low cost, lightweight and diversity of structural allotropes of carbon. We reported here the synthesis of a new type of unzipped multiwalled carbon nanotubes/titanium dioxide (UzMWCNT/TiO₂) nanocomposite by the two-stage procedure. By the modified Hummers method, multiwalled carbon nanotubes (MWCNTs) were converted to oxidized multi-walled carbon nanotubes (O-MWCNT). Then, through a facile ultrasound-assisted route prepared UzMWCNT/TiO₂ nanocomposite. For this, the oxidized multiwalled carbon nanotubes are treated with TiCl₄ under an ultrasonic probe for 3 h to generate UzMWCNT/TiO₂ and then explored its environmental friendliness and energy applications as a supercapacitor. This novel UzMWCNT/TiO₂ nanocomposite was characterized using XRD, TGA, FT-IR, Raman, TEM and EDX analysis. The electrochemical performance can be evaluated by using cyclic voltammetry (CV) and galvanostatic charging-discharging (GCD) study. Finally, the electrodes prepared using UzMWCNT/TiO₂ nanocomposite have been analyzed through electrochemical impedance spectroscopy (EIS) to probe the charge transfer characteristics and the results are consistent with other electrochemical measurements.

Stoichiometry-Controlled MoxW1-xTe2 Nanowhiskers: A Novel Electrocatalyst for Pt-Free Dye-Sensitized Solar Cells

Novel polymorphic Mo_xW_1-xTe₂-based counter electrodes possess high carrier mobility, phase-dependent lattice distortion, and surface charge density wave to boost the charge-transfer kinetics and electrocatalytic activity in dye-sensitized solar cells (DSSCs). Here, we report the syntheses of stoichiometry-controlled binary and ternary Mo_xW_1-xTe₂ nanowhiskers directly on carbon cloth (CC), denoted by Mo_xW_1-xTe₂/CC, with an atmospheric chemical vapor deposition technique. The synthesized Mo_xW_1-xTe₂/CC samples, including 1T'-MoTe₂/CC, T_d-WTe₂/CC, T_d-Mo_0.26W_0.73Te_2.01/CC, and 1T'- & T_d-Mo_0.66W_0.32Te_2.02/CC, were then employed as different counter electrodes to study their electrochemical activities and efficiencies in DSSCs. The photovoltaic parameter analysis manifests that Mo_xW_1-xTe₂/CCs are more stable than a standard Pt/CC in the I^-/I₃^- electrolyte examined by cyclic voltammetry over 100 cycles. A 1T'- & T_d-Mo_0.66W_0.32Te_2.02/CC-based DSSC can achieve a photocurrent density of 16.29 mA cm^-2, a maximum incident photon-to-electron conversion efficiency of 90% at 550 nm excitation, and an efficiency of 9.40%, as compared with 8.93% of the Pt/CC counterpart. Moreover, the 1T'- & T_d-Mo_0.66W_0.32Te_2.02/CC shows lower charge-transfer resistance (0.62 Ω cm²) than a standard Pt/CC (1.19 Ω cm²) in electrocatalytic reactions. Notably, Mo_xW_1-xTe₂ nanowhiskers act as an electron expressway by shortening the path of carrier transportation in the axial direction from a counter electrode to electrolytic ions to enhance the reaction kinetics in DSSCs. This work demonstrates that the nanowhisker-structured 1T'- & T_d-Mo_0.66W_0.32Te_2.02/CC with high carrier mobility and robust surface states can serve as a highly efficient counter electrode in DSSCs to replace the conventional Pt counter electrode for electrocatalytic applications.

In situ carbon-supported titanium dioxide (ICS-TiO2) as an electrode material for high performance supercapacitors

Supercapacitors have attracted significant attention in the last few years as they have the capability to fulfill the demand for both power and energy density in many energy storage applications. In this study, an in situ carbon-supported titanium oxide (ICS-TiO2) electrode has been prepared using sucrose and TiO2 powder. The ICS-TiO2 powder was prepared by slipcasting, followed by the annealing of the TiO2 slurry. Sucrose was added to the TiO2 slurry as a soluble carbon source, and was converted into carbon at 600 °C then coated on the TiO2 particles. The morphological and structural evolution of the electrode was investigated by FEG-SEM, FEG-TEM, XRD, BET, FTIR, XPS and Raman spectroscopy. The electrochemical characterization of ICS-TiO2 demonstrated that this material exhibits an efficient value of specific capacitance (277.72 F g-1 at 25 mV s-1) for charge storage. ISC-TiO2 also exhibits a specific capacitance of 180 F g-1 at 2 A g-1 in a 1 M Na2SO4 aqueous electrolyte. The results suggest that ICS-TiO2 can be utilized as a high-performance electrode material for supercapacitors with desirable electrochemical properties.

Fe1-xS Modified TiO2 NPs Embedded Carbon Nanofiber Composite via Electrospinning: A Potential Electrode Material for Supercapacitors

Fe_1-xS-TiO₂ nanoparticles embedded carbon nanofibers (Fe_1-xS-TiO₂/CNFs) composite as a supercapacitor electrode material has been reported in the present work. The Fe_1-xS-TiO₂/CNFs composite was fabricated by electrospinning technique followed by carbonization under argon atmosphere and characterized by the state-of-art techniques. The electrochemical studies were carried out in a 2 M KOH electrolyte solution. The synthesized material showed a specific capacitance value of 138 F/g at the current density of 1 A/g. Further, the capacitance retention was about 83%. The obtained results indicate that the Fe_1-xS-TiO₂/CNFs composite can be recognized as electrode material in supercapacitor.

TiO2 NPs Assembled into a Carbon Nanofiber Composite Electrode by a One-Step Electrospinning Process for Supercapacitor Applications

In this study, we have synthesized titanium dioxide nanoparticles (TiO₂ NPs) into carbon nanofiber (NFs) composites by a simple electrospinning method followed by subsequent thermal treatment. The resulting composite was characterized by state-of-the-art techniques and exploited as the electrode material for supercapacitor applications. The electrochemical behavior of the as-synthesized TiO₂ NPs assembled into carbon nanofibers (TiO₂-carbon NFs) was investigated and compared with pristine TiO₂ NFs. The cyclic voltammetry and charge–discharge analysis of the composite revealed an enhancement in the performance of the composite compared to the bare TiO₂ NFs. The as-obtained TiO₂-carbon NF composite exhibited a specific capacitance of 106.57 F/g at a current density of 1 A/g and capacitance retention of about 84% after 2000 cycles. The results obtained from this study demonstrate that the prepared nanocomposite could be used as electrode material in a supercapacitor. Furthermore, this work provides an easy scale-up strategy to prepare highly efficient TiO₂-carbon composite nanofibers.

An efficient electrode material for high performance solid-state hybrid supercapacitors based on a Cu/CuO/porous carbon nanofiber/TiO2 hybrid composite

A Cu/CuO/porous carbon nanofiber/TiO2 (Cu/CuO/PCNF/TiO2) composite uniformly covered with TiO2 nanoparticles was synthesized by electrospinning and a simple hydrothermal technique. The synthesized composite exhibits a unique morphology and excellent supercapacitive performance, including both electric double layer and pseudo-capacitance behavior. Electrochemical measurements were performed by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The highest specific capacitance value of 530 F g-1 at a current density of 1.5 A g-1 was obtained for the Cu/CuO/PCNF/TiO2 composite electrode in a three-electrode configuration. The solid-state hybrid supercapacitor (SSHSC) fabricated based on this composite exhibits a high specific capacitance value of 330 F g-1 at a current density of 1 A g-1 with 78.8% capacitance retention for up to 10,000 cycles. At the same time, a high energy density of 45.83 Wh kg-1 at a power density of 1.27 kW kg-1 was also realized. The developed electrode material provides new insight into ways to enhance the electrochemical properties of solid-state supercapacitors, based on the synergistic effect of porous carbon nanofibers, metal and metal oxide nanoparticles, which together open up new opportunities for energy storage and conversion applications.

High-Performance Asymmetric Electrochromic-Supercapacitor Device Based on Poly(indole-6-carboxylicacid)/TiO2 Nanocomposites

A difunctional porous network of poly(indole-6-carboxylicacid) (PICA)/TiO₂ nanocomposites is first prepared using TiO₂ nanorod arrays as the scaffold. Because of the synergistic effect of PICA and TiO₂, the nanocomposites show good electrochemical performance, a high specific capacitance value (23.34 mF cm^-2), and excellent galvanostatic charge-discharge stability. Meanwhile, this nanocomposite can be reversibly switched (yellow, green, brown) with a high coloration efficiency (124 cm² C^-1). An asymmetric electrochromic-supercapacitor device (ESD) is also constructed using the PICA/TiO₂ nanocomposites as the anode material and poly(3,4-ethylenedioxythiophene) as the cathode material. This ESD has robust cycle stability and a high specific capacitance value (9.65 mF cm^-2), which can be switched from light green to dark blue. After charging, the device can light up a single LED for 108 s, and the energy storage level can also be monitored by the corresponding color changes. This constructed ESD will have great potential applications in intelligent energy storage and other smart electronic fields.

Three-Dimensional MoS2 @CNT/RGO Network Composites for High-Performance Flexible Supercapacitors

Two-dimensional atomically thick materials, reduced graphene oxide (RGO), and layered molybdenum disulfide (MoS₂ ) have been investigated as potential novel energy storage materials because of their distinct physicochemical properties. These materials suffer, however, from rapid capacity decay and low rate capability. This study describes a facile, binder-free approach to fabricate large-scale, 3D network structured MoS₂ @carbon nanotube (CNT)/RGO composites for application in flexible supercapacitor devices. The as-obtained composites possess a hierarchical porosity, and an interconnected framework. The electrochemical supercapacitive measurements of the MoS₂ @CNT/RGO electrode show a high specific capacitance of 129 mF cm^-2 at 0.1 mA cm^-2 . The symmetric supercapacitor devices based on the as-obtained composites exhibit a long lifetime (94.7 % capacitance retention after 10 000 cycles), and a high electrochemical performance (29.7 mF cm^-2 ). The present experimental findings will lead to scalable, binder-free synthesis of MoS₂ @CNT/RGO hybrid electrodes, with enhanced, flexible, supercapacitive performance, in portable and wearable energy storage devices.

Synthesis of rGO–Zn0.8Cd0.2S via in situ reduction of GO for the realization of a Schottky diode with low barrier height and highly enhanced photoresponsivity

Application of rGO–Zn_0.8Cd_0.2S in Schottky barrier diode with low barrier height and highly enhanced photoresponse.

Molybdenum diselenide/reduced graphene oxide based hybrid nanosheets for supercapacitor applications

The hybrid MoSe₂/rGO nanosheets were synthesized via a facile hydrothermal process. The hybrid nanosheets electrode showed enhanced specific capacitance value than that of the pristine MoSe₂. The MoSe₂/rGO nanosheets exhibited increasing capacitance retention of up to 180% for the long-term stability test of 10,000 cycles at high current density.

Supercapacitive performance of electrochemically doped TiO2 nanotube arrays decorated with Cu2O nanoparticles

Highly ordered TiO₂ nanotube arrays (TNAs) with enhanced electronic conductivity treated by introducing oxygen vacancies have been considered to be a promising electrode material for supercapacitors.

One-step hydrothermal synthesis of graphene decorated V2O5 nanobelts for enhanced electrochemical energy storage

Graphene-decorated V2O5 nanobelts (GVNBs) were synthesized via a low-temperature hydrothermal method in a single step. V2O5 nanobelts (VNBs) were formed in the presence of graphene oxide, a mild oxidant, which also enhanced the conductivity of GVNBs. From the electron energy loss spectroscopy analysis, the reduced graphene oxide (rGO) are inserted into the layered crystal structure of V2O5 nanobelts, which further confirmed the enhanced conductivity of the nanobelts. The electrochemical energy-storage capacity of GVNBs was investigated for supercapacitor applications. The specific capacitance of GVNBs was evaluated using cyclic voltammetry (CV) and charge/discharge (CD) studies. The GVNBs having V2O5-rich composite, namely, V3G1 (VO/GO = 3:1), showed superior specific capacitance in comparison to the other composites (V1G1 and V1G3) and the pure materials. Moreover, the V3G1 composite showed excellent cyclic stability and the capacitance retention of about 82% was observed even after 5000 cycles.

One step hydrothermal synthesis of a rGO–TiO2 nanocomposite and its application on a Schottky diode: improvement in device performance and transport properties

rGO–TiO₂ nanocomposite based Schottky diode shows improved performance and better transport properties compared to TiO₂.

Performance evaluation of highly conductive graphene (RGOHI–AcOH) and graphene/metal nanoparticle composites (RGO/Ni) coated on carbon cloth for supercapacitor applications

The application of graphene (RGO)-based composites as electrode materials in supercapacitors can be limited by the fabrication complexity and costs, and the non-environmentally friendly nature of the production process.

DNA mediated wire-like clusters of self-assembled TiO₂ nanomaterials: supercapacitor and dye sensitized solar cell applications

A new route for the formation of wire-like clusters of TiO₂ nanomaterials self-assembled in DNA scaffold within an hour of reaction time is reported. TiO₂ nanomaterials are synthesized by the reaction of titanium-isopropoxide with ethanol and water in the presence of DNA under continuous stirring and heating at 60 °C. The individual size of the TiO₂ NPs self-assembled in DNA and the diameter of the wires can be tuned by controlling the DNA to Ti-salt molar ratios and other reaction parameters. The eventual diameter of the individual particles varies between 15 ± 5 nm ranges, whereas the length of the nanowires varies in the 2-3 μm range. The synthesized wire-like DNA-TiO₂ nanomaterials are excellent materials for electrochemical supercapacitor and DSSC applications. From the electrochemical supercapacitor experiment, it was found that the TiO₂ nanomaterials showed different specific capacitance (Cs) values for the various nanowires, and the order of Cs values are as follows: wire-like clusters (small size) > wire-like clusters (large size). The highest Cs of 2.69 F g(-1) was observed for TiO₂ having wire-like structure with small sizes. The study of the long term cycling stability of wire-like clusters (small size) electrode were shown to be stable, retaining ca. 80% of the initial specific capacitance, even after 5000 cycles. The potentiality of the DNA-TiO₂ nanomaterials was also tested in photo-voltaic applications and the observed efficiency was found higher in the case of wire-like TiO₂ nanostructures with larger sizes compared to smaller sizes. In future, the described method can be extended for the synthesis of other oxide based materials on DNA scaffold and can be further used in other applications like sensors, Li-ion battery materials or treatment for environmental waste water.