High Efficiency Research Articles

Alkanediol–hexafluoroisopropanol amphiphilic supramolecular solvent: Fabrication, characterization, and application potential for doping control of hormones and metabolic modulators in human urine

A novel amphiphilic supramolecular solvent (SUPRAS) was developed by hexafluoroisopropanol (HFIP)-induced self-assembly of 1,2-hexanediol in an aqueous matrix. Its application potential in multiclass determination was assessed by extracting from urine 10 prohibited hormones and metabolic modulators (log P from 2.38 to 7.57) listed by the World Anti-Doping Agency (WADA). This SUPRAS is stably formed across a wide pH range (2–12) and is unaffected by salt concentrations (<10 % g mL−1 of NaCl), and it has a higher density than water. The dehydration and hydrogen bonding ability of HFIP, as well as hydrophobic interactions between alkanediols, dominates the formation of the SUPRAS. The nanostructure of the SUPRAS, composed of 1,2-hexanediol, HFIP, and a high content of water (>25 %, w/w), forms large spherical micellar aggregates (10–100 μm) that exhibit amphiphilic properties. A 1,2-hexanediol-HFIP SUPRAS-based liquid-phase microextraction (LPME) method for detection of selected prohibited drugs in urine coupled with liquid chromatography–tandem mass spectrometry (LC-MS/MS) was established, optimized, and validated. The method showed fast extraction time (30 s of vortex) and low solvent consumption (160 μL of organic solvent). Under the optimal conditions (7 % g mL−1 of 1,2-hexanediol, 10 % v/v of HFIP), the SUPRAS achieved high extraction efficiencies (>80 %) and an enrichment factor of 6.0, with minimal matrix effects for all analytes due to its high amphiphilicity and large surface area. The method demonstrated excellent linearity (R ≥ 0.9909), with method limits of detection ranging from 0.018 to 0.18 ng mL−1 and method limits of quantitation ranging from 0.060 to 0.60 ng mL−1, which are well below the minimum required performance levels set by authorities. Furthermore, the intra- and inter-day relative recoveries for spiked human urine samples varied in the ranges of 90.3 %–121 % and 88.1–119 %, respectively, with relative standard deviations less than 13 % and 19 %, respectively. This SUPRAS-based LPME method proves to be simple, highly efficient, and eco-friendly, and it has promising potential for multiclass determination in doping control.

A regulatory power split strategy for energy management with battery and ultracapacitor

Electric vehicle batteries face fast degradation due to the high frequency of charging/discharging cycles and great peak power demands. Lifetime, continuity of supply and power density of these batteries affect the performance of electric vehicles (EVs). Hybrid energy storage systems (HESS) offers a feasible solution by incorporating other energy storage elements like ultra-capacitor (UC) along with battery. Their combination provides higher efficiency and better performance in terms energy/power density. UC can behave like a power buffer when the EV is accelerating and regenerating. The HESS needs a controller that can split the available power between different sub systems as per demand. This paper presents a regulatory control strategy useful in HESS with battery and UC for the speed regulation of a brushless DC (BLDC) motor using a 3-port bidirectional DC-DC converter. The regulatory control strategy monitors the state of charge (SOC) of UC and a fuzzy logic controller regulates the power flow between HESS and the motor. Simulation in MATLAB validates the efficacy of the strategy. Simulation results and hardware evaluation confirm that the regulatory control scheme is effective in splitting the available power according to the load demand and achieves better energy efficiency.

A Li-ion battery charger based on LDO regulator with pre-charge mode in 180 nm CMOS technology

This paper presents a novel Li-Ion battery charger that utilizes a low-dropout (LDO) regulator and incorporates four control modes: low constant current mode, pre-charge current mode, fast constant current mode, and constant voltage mode. The charger aims to meet specific criteria such as high precision, high efficiency, and small form factor. Through simulation results, the following specifications were obtained using a 1.8 V supply in a 0.18 μm complementary metal–oxide–semiconductor (CMOS) technology: a trickle current of 124.7 mA, a pre-charge current of 466.94 mA, a maximum charge current of 1.06 A, and a charge voltage of 4.21 V. The proposed charger demonstrates an efficiency of 92%.

Power converters analyzed in energy storage systems to enhance the performance of the smart grid application

This paper implements and compares the existing power supply converters for an energy storage system to determine the best suited for the smart grid application. A survey of different DC-DC converters is carried out to analyze the battery's overall performance. The main objective is to identify this application's most appropriate energy storage device. The advantages of this technology have high efficiency and reliability, which can connect various energy sources and reduce conduction losses in the power converters. Through the converter control, reference currents are imposed to charge the battery. The battery nominal voltage needs to change to see which type of converter is the most suitable and robust. Simulation results show that the operating ranges of boost-buck, buck-boost, and buck-boost converters with negative output voltage enhance the efficiency of battery and renewable energy sources and compared the DC converters to know the functional voltage for the energy storage system. The power converter's efficiency and control facility will allow us to link the energy storage system with the power grid. The overall installation is established using MATLAB/Simulink software.

Boosting peroxymonosulfate activation with a composite of highly dispersed FeS2 nanoparticles anchored on N-doped biochar for efficient tetracycline degradation

The rational design of inexpensive peroxymonosulfate (PMS) activators with high efficiencies is still in high demand. Herein, a composite with highly dispersed FeS2 anchored on nitrogen-doped biochar (FeS2@NBC) was prepared via a hydrothermal process and used for PMS activation to degrade the pollutant tetracycline (TC). Benefiting from in situ growth of FeS2 on the NBC surface, FeS2@NBC alleviated the side effects caused by FeS2 agglomeration, and the synergistic catalytic effect of the FeS2 nanoparticles and N-doped biochar resulted in excellent performance. The optimal FeS2@NBC/PMS system could degrade 87.6% of TC within 10min, and it exhibited adaptability to pH changes and the presence of common inorganic anions. A comprehensive study involving radical scavenging experiments, electron paramagnetic resonance (EPR) spectroscopy, electrochemical tests and XPS analyses revealed that the singlet oxygen (1O2) and hydroxyl radical (•OH) were the dominant reactive oxygen species (ROS), the sulfate radical (SO4•−) and electron transfer were involved in the TC degradation process. Moreover, three degradation pathways were indicated by LC−MS detection, and the toxicities of the degradation intermediates were predicted and evaluated. Finally, FeS2@NBC showed excellent reusability and stability after five cycles of TC degradation. This work provides a reference for designing efficient catalysts that can be combined with metal sulfides and biochar for efficient PMS activation.

Myo-inositol as a carbon source in Chlorella sp. production

The study aimed to investigate the possible use of myo-inositol as a carbon source in Chlorella sp. culture. Firstly, experiments were conducted with different myo-inositol concentrations and glycerol in flasks. Secondly, a laboratory-scale tubular photobioreactor (PBR) was operated with CO2 and myo-inositol to determine performance under industrial production conditions. The highest dry weight of the experiments with flasks was 1.62 ± 0.02 g.L−1 and was obtained with 1 g.L−1 myo-inositol concentration. Myo-inositol yielded two times higher lipid accumulation compared to glycerol in the experiment with flasks and 12 % compared to CO2 in the PBR experiment. The results revealed that myo-inositol is one of the most efficient carbon sources with 0.86 CBCR (carbon to biomass conversion rate). Even if myo-inositol is more expensive than many carbon sources such as CO2, high efficiency and less light energy expenses make it a competitive carbon source in Chlorella sp. production.

Flotation activation mechanism of trithiocyanuric acid to malachite

Malachite is a typical refractory copper oxide mineral. In this paper, trithiocyanuric acid (TMT) was used as a novel activator for the activated flotation of malachite for the first time. The effect of TMT on the flotation behavior of malachite was studied and the activation mechanism was discussed. The flotation test results showed that TMT exhibited superior activation performance over sodium sulfide, achieving a high flotation recovery rate of 97.50 % at TMT 90 mg/L and pH 7. The contact angle confirmed malachite improved from 53.3° to 90.1° after TMT treatment, indicating enhanced hydrophobicity of the mineral surface. FTIR and EDS analyses provided clear evidence of chemical adsorption of TMT tautomers onto the malachite surface. SEM images further illustrated the presence of dense particles formed after TMT treatment. XPS revealed that TMT exhibited a strong adsorption effect on malachite, leading to an increase in copper sites and the formation of highly reactive Cu+. The activation mechanism was elucidated as the reaction between Cu sites on malachite and S and N atoms in TMT, forming Cu-S and Cu–N fractions crucial for activation. The high efficiency and low dosage of TMT make it a promising activator for malachite, offering a novel avenue for the effective recovery of malachite-type copper oxide ore resources.

Analysis of nickel oxide as a counter electrode for dye-sensitized solar cells using OghmaNano software

Dye-sensitized solar cells (DSSCs), a promising green technology, convert solar energy into electricity more cost-effectively than traditional solar cells. While platinum (Pt) is commonly used in DSSCs, its high cost and toxicity limit practical applications. Recent research aims to develop low-cost counter electrodes with high efficiency. Nickel oxide (NiO), a p-type semiconductor with a wide bandgap, good transmittance, and suitable work function, emerges as a potential alternative for counter electrode of DSSCs. In this work, DSSCs with NiO of thicknesses varying from 100 nm to 1000 nm were simulated to determine its influence on photovoltaic performance using OghmaNano software. The structure of simulated solar cells consists of NiO as counter electrode, zinc oxide (ZnO) as photoanode, N719 as dyes, electrolyte as charge carrier transport, and fluorine-doped tin oxide (FTO) as a contact layer. There are five data of NiO used as an active layer. From the simulation results, NiO-doped gold exhibits the highest power conversion efficiency (PCE) of 15.95% at a thickness of 700 nm, while pure NiO shows the lowest PCE with 4.53% at a thickness of 600 nm. These results have demonstrated that NiO can replace Pt as a counter electrode for DSSCs and doping plays a vital role in increasing efficiency.

Bidirectional DC-DC Converter and Improved Electrical Vehicle Dynamic Response Control

Background: In automotive applications where bidirectional power flow is necessary to lighten the power system, dual active bridge (DAB) converters are frequently employed. Variations in the required output voltage, erratic input voltage, and shifting loads all have an impact on this converter. As a result, converter performance has to be improved. To increase efficiency, the current stress of the DC-DC converter must be optimised. This paper proposes a control scheme for the coupled inductor bidirectional DC-DC (CIB DC-DC) converter utilising both model predictive control (MPC) and a proportional-integral (PI) controller. The integration of these control techniques aims to enhance the performance and efficiency of the converter. Methods: The MPC algorithm is employed to predict the converter's future behaviour based on a dynamic model, taking into account system constraints and performance criteria. By optimising the control action over a finite time horizon, the MPC algorithm ensures an optimal response, considering the current state and anticipated changes. Additionally, a PI controller is incorporated to augment the control strategy. The proportional component of the PI controller enables a fast initial response to the error between the desired and actual converter outputs. The integral component eliminates steady-state errors and provides robustness against disturbances, resulting in improved overall system performance. Results: The proposed control scheme is implemented and evaluated through simulations and experimental tests on a prototype converter. The results demonstrate the effectiveness of the combined MPC and PI controller approach. Conclusion: The coupled inductor bidirectional DC-DC (CIB DC-DC) converter using MPC can provide precise control of power flow between two voltage domains, enabling efficient bidirectional power transfer. The predictive capabilities of MPC allow it to adapt to varying load conditions and respond quickly to changes, ensuring stable operation and accurate regulation of voltage and current. Overall, the coupled inductor bidirectional DC-DC converter controlled using MPC over PI offers improved performance, efficiency, and flexibility compared to traditional control methods. MPC can handle the complex dynamics response and non-linear characteristics of the converter, making it suitable for bi-directional vehicle charging applications, where precise control and high efficiency can be achieved.

A nano-oxygen generator for enhanced light-controlled elimination of anaerobic bacteria in periodontal infections

A nano-oxygen generator for enhanced light-controlled elimination of anaerobic bacteria in periodontal infections

Tannic acid strengthen adhesion of poly(AAm-co-GG) hydrogels for multiple solid surfaces repairing

This study aims to develop bio-compatible mechanically robust, adhesive hydrogels using acrylamide and gellan gum. Tannic acid (TA) and N, N-methylene bisacrylamide (MBA) were used as physical and chemical crosslinkers respectively. Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) analysis verified the successful synthesis of hydrogels through free radical addition polymerization. The rheological tests, such as frequency sweep, creep recovery, and amplitude sweep were performed to evaluate the effect of TA on the adhesive behavior and viscoelastic properties of hydrogels. Results highlighted the pivotal role of polymer chain interactions in regulating the adhesive behavior. The tannic acid concentration was varied to assess the adhesive performance, higher tannic acid concentration resulted in improved adherence. The adhesion strength order was received as 33.6 > 18 > 7.56 > 6.7 > 6.23 kPa. The prepared adhesive hydrogels performed exceptionally well on wood, cloth, rubber, glass, and ceramics-like materials. Furthermore, the hydrogels were practically found efficient at low as well as at high temperatures. The low price, high efficiency, easy to synthesize, and bio-friendly. etc. characteristics can make these hydrogels to be applied convincingly as adhesives in the future.

Lipid-based Nanocarrier Drug Delivery Approach for Biomedical Application

Abstract: The development of nanosized drug-carrier systems has been investigated over the past few decades using various techniques. The two main categories of these systems are polymeric nanoparticles and lipid nanoparticles (LNPs). The toxicological risk associated with lipid nanoparticles is significantly lower than the danger associated with polymeric nanoparticles due to the materials' natural and biological origins. Lipid-based drug delivery systems like Nanostructured lipid carriers (NLCs) and Solid Lipid Nanoparticles (SLNs) are well-established nanotechnology systems for preparing all major pharmaceuticals. These delivery systems can be scaled up with easy manufacturing procedures and are biocompatible. NLCs are the second generation of lipid-based nanocarriers (SLNs), formed by combining solid and liquid biocompatible lipids to form an unstructured matrix that provides high entrapment efficiency of active constituents. LNPs can promote the distribution of active pharmaceutical ingredients to the target site. Increasing the active drug concentration to target organ LNPs enhances the therapeutic effectiveness and reduces the side effects. This paper reviews the structure of SLNs and different NLCs, various steps involved in manufacturing lipid nanoparticles, excipients used in the formulation, and applications for targeted drug delivery.

Development of high-performance Mo doped WO3 photo-electrochromic devices

In recent years, there has been a growing focus on reducing energy consumption, particularly in buildings. One effective method proposed by scientists is the use of intelligent photoelectric color-changing glass. While previous studies in this field have mainly concentrated on the rapid chromic performance, this study aims to enhance the shading rate by developing a photo-electrochromic bright window using the Mo doped WO3 sol-gel method. The study investigates the impact of different levels of MoO3 doping on the photo-electrochromic performance. The results demonstrate that increasing the MoO3 content leads to a wider coloring range and faster color change response, with transmittance values dropping below 25 % compared to the original transmittance of approximately 80 %. Particularly, there is a significant 55 % (ΔTC) change in transmittance for coloration at the wavelength of 550 nm, which is the most responsive to the human eye, compared to previous research. Furthermore, the smart windows exhibit stable switching for transmittance modulation, maintaining consistency over 20 repeated coloration and bleaching cycles. Overall, the photo-electrochromic film prepared using the doped sol-gel method exhibits excellent performance in terms of high-quality photo-electrochromic layers, short response time, high coloration efficiency, and long service life. This research shows the potential of smart windows in various applications, including energy-saving, smart displays, supercapacitor devices, and anti-counterfeiting.

23.6 % Efficient perovskite-organic tandem photovoltaics enabled by recombination layer engineering

Recombination layers are crucial in achieving high power conversion efficiency (PCE) in tandem solar cells. Here, we report the development and optimization of recombination junctions for high PCE perovskite-organic tandem solar cells (PO-TSCs). We choose a wide bandgap perovskite (1.79 eV) for the front subcell and a narrow bandgap (1.36 eV) organic bulk heterojunction (BHJ) for the rear subcell. The optimal thicknesses of the perovskite and organic layers were determined to be 260 and 100 nm, respectively, based on the analysis of Transfer-Matrix optical simulations. Our results demonstrate that the optimal recombination layer consists of an ultrathin layer of indium zinc oxide IZO (∼ 2 nm) deposited on MoOx/2PACz, which delivers a PCE of 23.6 %. This high PCE is attributed to the high transparency of the recombination layer in the NIR spectra region and the low sheet resistance of IZO. Furthermore, we provide a theoretical analysis of the potential efficiency of PO-TSCs as a function of front and rear subcells and predict a maximum theoretical PCE value of more than 36 %. Our work highlights the importance of selecting the proper recombination layer design for achieving high-performance PO-TSCs.

Modulating the d-band center of single-atom catalysts for efficient Li2S2-Li2S conversion in durable lithium-sulfur batteries

Enhancing the conversion of insoluble Li2S2-Li2S to improve sulfur utilization has become an essential strategy for Lithium-Sulfur (Li-S) batteries. The proposed approach employs single-atom catalysts (SACs) known for their high atomic usage efficiency to enable in-situ reactions with Li2S2. However, the origin and mechanisms of various SACs involved in the Li2S2 to Li2S reduction reaction are not fully elucidated. Herein, we reveal the underlying mechanism of Li2S2-Li2S reduction catalysis on Mn atoms by examining the electronic structure of d orbitals. Theoretical calculations indicate that substituting a S atom for N in the first coordination structure of Mn SACs elevates the Mn d-band center and simultaneously enhances the hybridization between the Mn d orbitals and the p orbitals of sulfur species. This alteration not only improves the anchoring of lithium polysulfides, leading to better adsorption but also accelerates the conversion kinetics of Li2S2 to Li2S due to the improved intrinsic catalytic activity of SACs. As a result, the Li-S batteries equipped with the SAMn-based cathode deliver an impressive initial capacity of 1343.9 mAh g−1 at 0.1 C, exceptional rate capability of 782.4 mAh g−1 at 3 C, and maintain a low degradation rate of approximately 0.025% per cycle over 1000 cycles at 1.0 C. Furthermore, with a sulfur loading of 6 mg cm−2, the S/SAMn@NSC cathode achieves a reversible areal capacity of 4.4 mAh cm−2 at 0.1 C. This study significantly advances the kinetics of solid-solid transformation in Li-S battery cathodes through catalysis facilitated by single-atom d-band regulation.

Advancements in printed components for proton exchange membrane fuel cells: A comprehensive review

Proton Exchange Membranes (PEM) are a promising technology for fuel cells and electrolyzer cells, in line with societal goals for clean and sustainable fuel conversion and generation, respectively, in a vast field of applications. PEM fuel cell (PEMFC) technology has an important advantage for energy conversion applications, because it requires a lower operating temperature and is lighter and more compact than other technologies, which makes it ideal for portable and transportation applications. However, open issues remain to be addressed for PEMFC that hinder their widespread adoption, both on the technical side, such as too high operational temperature range, cell efficiency, and long-term stability, as well as on the industrial side with implementation issues, material and device component availability, and cost. PEM technology research usually focuses on the synthesis of novel materials such as non-noble metal catalysts and non-halogenated membranes. In parallel, developing high-throughput and cost-effective manufacturing methods for components, in particular Membrane Electrode Assembly (MEA), can also lift an important barrier to their mass production, thus contributing to the same goals and securing industrial provision. From this perspective, printing technologies such as spray coating, inkjet printing, and screen printing have emerged as promising approaches with the required precision and scalability. This review covers recent advancements and developments in advanced PEMFC technology manufacturing, with a focus on 2D printing methodologies to fabricate some or all of the MEA components. Leveraging these techniques as simplified large-area manufacturing methods for PEM technology can become a more viable and industrially attractive solution. This work presents a comparison study addressing the key progress indicators both in process and in characterization to build a working framework in which both scientists, engineers and manufacturers can collaborate toward the industrial implementation of this emergent field.

A Comprehensive Review on Niosomes as a Tool for Advanced Drug Delivery.

Over the past few decades, advancements in nanocarrier-based therapeutic delivery have been significant, and niosomes research has recently received much interest. The self-assembled nonionic surfactant vesicles lead to the production of niosomes. The most recent nanocarriers, niosomes, are self-assembled vesicles made of nonionic surfactants with or without the proper quantities of cholesterol or other amphiphilic molecules. Because of their durability, low cost of components, large-scale production, simple maintenance, and high entrapment efficiency, niosomes are being used more frequently. Additionally, they enhance pharmacokinetics, reduce toxicity, enhance the solubility of poorly water-soluble compounds, & increase bioavailability. One of the most crucial features of niosomes is their controlled release and targeted diffusion, which is utilized for treating cancer, infectious diseases, and other problems. In this review article, we have covered all the fundamental information about niosomes, including preparation techniques, niosomes types, factors influencing their formation, niosomes evaluation, applications, and administration routes, along with recent developments.

A two-stage flank correction method for the continuous generation of face gears

Face gear pairs are particularly suitable for application in advanced equipment drivetrains with intersecting shafts. The continuous generation process of face gear tooth flanks using worms offers high machining efficiency, but achieving high accuracy in this process remains a considerable challenge. A two-stage flank correction method for face gears ground by worms on a computer numerical control (CNC) generator is proposed. This method comprehensively involves both the worm dressing and face gear grinding stages, considering the actual machine tool structure and constant offsets among its axes. Firstly, the machining kinematics for both stages are derived and the high-order tooth flank model of the face gears is developed. Secondly, the sensitivity of tooth flank deviations to variations in the kinematic coefficients is analyzed, and the deviations on both flanks of the tooth space generated with initial kinematics are measured. Finally, three cases of correction for the measured deviations are compared using the proposed method. Correcting only the grinding stage is effective and computationally inexpensive, and employing this case for manufacturing face gear tooth flank significantly reduces deviations.

The effect of anti-agglomerant tween on the thermal and rheological properties of TBAF semi-clathrate hydrate slurry used for cold storage systems

Hydrate, as a phase change cold storage material, can form the slurry with certain fluidity, enabling convective heat transfer during both the heat absorption and heat release stages (cold storage or refrigeration), with high heat transfer efficiency. However, high viscosity and significant flow pressure losses are the principal challenges limiting its advancement. The paper selected four non-ionic surfactants as hydrate anti-agglomerants (Tween 20, 40, 60, 80) and utilized DSC to examine their effects on the thermal properties of TBAF semi-clathrate hydrate slurry at three theoretical hydrate concentrations (with mass fraction of 0.60, 0.70, and 0.80). Additionally, it measured the viscosity variation during the endothermic dissociation stage of the TBAF hydrate slurry and calculated the flow pressure losses in hydrate slurries within various pipe diameters. The results revealed that the presence of Tween increased the hydrate growth within the slurry, resulting in a higher available phase change enthalpy. Tween 80 demonstrated the most significant increase in enthalpy increasing effect, with an available phase change enthalpy ranging from 128.08 to 170.03 kJ/(kg·slurry) and an increase in enthalpy of 52.14 % to 91.62 %. For TBAF hydrate slurries with the theoretical hydrate mass fraction of 0.60, the addition of Tween 20 or Tween 80 significantly reduced viscosity, dropping to between 57.6 mPa·s and 116 mPa·s, and reducing viscosity by 43.4 % to 71.9 %. Furthermore, most flows with anti-agglomerants were in the laminar regime. The addition of Tween 20 and Tween 80 achieved the maximum reduction in flow pressure loss per unit length, with the highest reduction being 80.2 % (0.11 kPa/m) and 71.1 % (0.15 kPa/m), respectively. Both the phase change enthalpy of the hydrate and the viscosity of the hydrate slurry impacted the flow pressure drop within pipes. Increasing phase change enthalpy and reducing viscosity are effective strategies for mitigating flow pressure drop.

Developing TiCo2O4 spinel based on rGO nanosheet to enhance electrochemical performance of OER activity

The reduction of fossil fuel reserves and the deterioration of environmental conditions have led to a worldwide concern with producing significant amounts of energy in a sustainable manner. The production of electrocatalysts for the oxygen evolution reaction (OER) is imperative for widespread commercialization of water electrolyzers. The electrocatalysts must exhibit improved electrocatalytic behavior while being cost-effective. This work presents simple hydrothermal route for producing a TiCo2O4 nanostructure with a spherical morphology, which is supported on reduced graphene oxide sheets (rGO). The nanocomposite has been subjected to an investigation of its morphological, structural and electrochemical characteristics. This material exhibits promise for electrochemical water splitting due to its significant electroactive surface area, distinctive morphology and metal ions (M+) synergetic effect on its electrocatalytic performance. The nanostructure of TiCo2O4/rGO-has been observed to exhibit robust electrocatalytic activity, underscoring the significance of the present study. Additionally, presented are the enduring stability of the OER, along with the reduced overpotential (269 mV@10 mA cm−2), decreased Tafel slope (37.56 mV dec-1) with greater electrochemical active surface area. Our finding suggests that the TiCo2O4/rGO nanohybrid exhibited high electrocatalytic efficiency and can be utilized in diverse electrochemical applications.