Transition metal oxides (TMO) have attracted significant attention in the field of electrochemical energy storage devices due to their unique electronic structure and enhanced redox chemistry. In this report, we have prepared a Mn-doped NiFe2O4 nanostructured electrode sample for supercapacitor potentials. Some surface-structural probing of the synthesized materials was carried out, and the results revealed the formation of nanosheet with a spinel cubic structure and the composition of corresponding elements. Raman and Fourier transform infrared spectroscopy (FTIR) spectra studies also reaffirmed the NiFe2O4 spinel structural integrity with both octahedral and tetrahedral sites. The electrochemical measurements of the fabricated electrodes revealed enhanced charge storage performance, depending on the intercalated electrolytic ions and Mn-dopant content. The findings indicate that the 5

Abstract Agricultural biomass offers a sustainable and cost-effective precursor for synthesizing activated carbon (AC) electrodes in energy storage systems, addressing both the global energy crisis and the environmental challenges of fossil-based materials. Biomass-derived carbons have gained increasing attention for supercapacitor applications due to their natural abundance, tunable porosity, and excellent electrochemical properties. This review critically examines recent progress in processing routes, activation strategies, and structure-property relationships of AC derived from agricultural wastes. Emphasis is placed on emerging approaches such as heteroatom doping, template-assisted activation, and composite design that enhance energy density and cycling stability. The novelty of this work lies in its integrated analysis of synthesis–performance correlations and the identification of future pathways toward scalable, green production of high-performance, biomass-derived AC electrodes for next-generation supercapacitors.

The development of pseudocapacitive electrodes with enhanced charge-storage capability is crucial for advancing high-performance electrochemical energy storage devices. In this work, NiO and NiOₓSγ thin-film electrodes were directly fabricated via a facile electroless deposition route using ammonium thiosulfate as an in-situ sulfur source to investigate the influence of sulfur incorporation on the microstructure and electrochemical performance. Structural characterization revealed that sulfur incorporation transformed the sparsely distributed NiO nanocrystals into a dense, interconnected mesoporous architecture with increased electrochemically active surface area and improved ion-transport pathways. X-ray diffraction and Raman analyses confirmed the formation of a mixed NiOₓSγ phase with sulfur-induced structural defects. Electrochemical measurements demonstrated that sulfur incorporation significantly enhanced the pseudocapacitive behavior, yielding a specific capacitance of 305 F g⁻¹ at 10 mV s⁻¹ and 164 F g⁻¹ at 0.2 mA cm⁻², together with improved charge-transfer kinetics and reduced interfacial resistance compared with pristine NiO. Mott–Schottky analysis further revealed an increased donor density and a more negative flat-band potential, indicating enhanced charge transport characteristics. These results demonstrate that sulfur-induced microstructural and electronic modulation of electroless-deposited NiOₓSγ thin films provides an effective strategy for developing scalable, high-performance pseudocapacitive electrodes for next-generation electrochemical energy storage devices.

In this report, we have synthesized activated carbon (AC) from an agricultural waste raw material (Cassava peel (CP)) using a chemical activation approach. The processing temperature has been varied (600 to 900 degrees C) to modulate microstructure, porosity, graphitization, and disorder with a view to optimizing the AC charge storage performance of the supercapacitor electrode material. Microstructural characterization revealed micro-meso porous amorphous AC materials with modulated pore structure, surface area, and defect states under varying carbonization temperature. Modifications in the D-and G- Raman peak parameters were also achieved by varying temperature. The Raman spectra D and G bands parameters and ID/IG values characteristic of highly disordered nanocrystalline carbon are consistent with structural features expected near the Stage I-Stage II transition region of the Ferrari-Robertson model. The Randle-Sevcik model verification of the material's charge storage mechanism also revealed improved capacitive actions up to 76% with increasing scan rate. The charge storage measurement also gave an optimum capacitance value for the CP-derived AC sample at 800 degrees C carbonization temperature as 441.56 F g(-1), ascribable to its superior balances in its microstructural, charge transfer, and degree of graphitization and disorder features. The study reveals how the carbonization temperature affects the CP-derived AC material's microstructural development and electrochemical charge storage capabilities of the biomass-derived carbon and reaffirms Raman spectroscopy as a potent method that enables quick screening to uncover mesoporous carbons with superior capacitance in supercapacitors.

A Co3O4/V2O5 bilayer heterostructure was successfully fabricated on ITO/glass substrates via sequential electrodeposition and comprehensively evaluated for its structural, vibrational, and optoelectronic properties toward ultraviolet (UV) photodetection. SEM analysis revealed a morphological transformation from the granular V2O5 and densely packed Co3O4 textures to a uniform, compact nanostructured network in the Co3O4/V2O5 heterostructure, indicating enhanced interfacial adhesion and surface coverage. Elemental mapping confirmed a homogeneous distribution of V, Co, and O elements without phase segregation. XRD patterns verified the coexistence of orthorhombic V2O5 and cubic Co3O4 phases, exhibiting interfacial strain-induced peak shifts, suppression of the (301) plane of V2O5, and broadened diffraction peaks, signifying improved crystalline coherence and structural coupling. Raman spectra further validated the phase purity and distinct vibrational features of both oxides. UV-visible absorption spectra displayed modulated band transitions, while Tauc's plots revealed tunable optical bandgaps ranging from 2.35 to 2.59 eV, depending on material composition and heterostructure formation. The fabricated UV photodetector demonstrated excellent photoresponse characteristics, including high responsivity and strong detectivity, attributed to efficient charge separation and transport at the heterostructure Co3O4/V2O5 interface. These findings establish the Co3O4/V2O5 heterostructure as a promising and scalable oxide-based platform for high-performance UV photodetectors and related optoelectronic applications.

This study investigates Ni2+/Co2+ substitution effects on microstructure of spinel ferrite [Ni1-yCoyFe2O4 (0 <= y <= 1)] composite nanoparticles, prepared by sol-gel driven hydrolysis. Electron microscopy studies revealed the formations of uniformly distributed nanostructures with agglomerated and strongly interconnected tetragonal grains. X-ray diffraction (XRD) study confirmed the formation of single-phase cubic spinel structured nano-crystals in all compositions, with inconsistent variations of the lattice parameter and crystallite size as the Ni2+/ Co2+ ratio changes. The Raman spectra revealed additional vibrational modes which confirmed the localized symmetry distortions, that could have occurred as a result of ionic radius mismatch of Ni2+/Co2+/Fe3+ cations at the octahedral sites. The vibrational stretching of metal-oxygen bond within the tetrahedral and octahedral sites were validated from infrared (FTIR) study. Charge storage studies also indicates that although, substituting Ni2+ with Co2+ in ferrite compounds can enhance electron hopping by occupying the octahedra B-sites, however, excessive Co content can create severe structural distortion by increasing the interplanar d-spacing, which reduces active sites and lowers electrical conductivity response. Thus, with its high specific capacity/capacitance (70.28 mAh g-1/632.4 Fg-1) at 0.5A/g, outstanding rate capability, exceptional cycling stability, and low charge transfer resistance, Ni0.5Co0.5Fe2O4 showed superior electrochemical performance among the Ni1-yCoyFe2O4 series, making it a suitable material for advanced energy storage applications.

Proton batteries are a promising, sustainable alternative to lithium-ion batteries due to the abundance of hydrogen and its smaller ionic radius, which facilitates its seamless intercalation in electroactive materials. However, their progress depends on the development of cost-effective, high-capacity electrode materials. Herein, we report the successful fabrication of a binder-less, defect-engineered WO3-x/WO3 pseudocapacitive proton storage electrode (HTT_WO3-x) through scavenging of atomic sub-surface oxygen from hydrothermal-treated electro-coated WO3 films (HTT_WO3). The defect-engineered electrode (HTT_WO3-x) combined improved mass load with enhanced electronic and ionic transport behaviour. The electrode achieved an areal capacitance of 42.13 mF center dot cm-2 at 5.00 mV center dot s-1, approximately 300 % higher than the electro-coated WO3 seed electrode. The hydrothermal treatment yielded an increased mass load and areal capacity, further improved through lowered impedance parameters and better interfacial characteristics by defect engineering. This study offered a facile method for achieving binder-free coating of high-mass load proton storage active materials without compromising their ionic and electronic transport.

In this study, heterojunction UV radiation photodetector (PD) based on ZnO nanolaminate and orthorhombic nanostructured MoO3 thin film, was fabricated using a cost-effective electrochemical deposition process. Some surface structural studies unveil the deposited materials' characteristics suitable for effective photoabsorption and photoelectric charge carriers' transport. The fabricated PD demonstrated excellent UV photo-response properties, thanks to the intrinsic UV absorption characteristics of ZnO nanolaminate and enhanced charge carriers' separation and transport properties brought through its synergistic band interaction with the MoO3 underlain. The UV PD device with MoO3 underlain demonstrated optimal performance with a high photocurrent compared to its counterpart (without MoO3). It exhibited high UV radiation responsivity and detectivity values of 0.7 A/W and 5.3 x 1010 Jones, respectively under weak irradiation of UV (lambda = 365 nm) at 0.5 mW/cm2 power density. The result demonstrated the potential of ZnO/MoO3 heterojunction as an excellent recipe for highperformance UV radiation detection.

Recently, the use of nanostructured material has continued to gain huge recognition in healthcare-related fields owing to their strong biological activity in the prevention of bacterial growth, thus minimizing the spread of bacterial infections. In this current research, we evaluated the effect of annealing temperature on some surface properties and antimicrobial efficacy of molybdenum trioxide (MoO3) nanostructure against two urinary tract infections (UTIs) pathogens. Some surface structural investigation of the samples revealed an amorphous nestlike MoO3 nanoparticle which exhibited a phase change into well-defined nanorods upon annealing. The deposited films' average crystallite sizes were found within the range of 35.4 to 52.1 nm depending on annealing temperature. Optical studies from UV-visible solar spectra revealed the deposited MoO3 film exhibited tuneable optical band structure with band-gap and Urbach energy values between 2.90 to 3.21 eV and 0.88 to 0.90 eV, respectively, depending on annealing temperature. The antimicrobial action of MoO3-coated films towards the Gram-positive (E. feacalis) and Gram-negative (E. coli) UTI bacteria pathogens revealed great efficiency that decreased with an increase in annealing temperature. Moreover, superior activity was recorded against Grampositive bacteria when compared to Gram-negative bacteria. These results strongly indicate the use of MoO3 nanostructure as a potential antimicrobial agent for the control of urinary tract infections. The study reaffirmed surface microstructure and optical band structure of MoO3 film can be tailored by subjecting it to some deposition heat treatments. It also unveiled the antimicrobial potencies of the spincoated MoO3 nanoparticles can be tailored via annealing processes.

Supercapattery represents a new energy storage device technology aimed at closing the gap between the supercapacitor's high power density and the battery's high energy density. Therefore, this report unveiled the utilization of binder-free solution-grown Ni(OH)2/S@MnO2 heterostructured electrode film in the fabrication of a novel hybrid solid-state supercapattery planar device. Some surface characterization of the material revealed successful sulfurization of electrodeposited particulate MnO2 film (S@MnO2), forming a base core layer for the amalgamation of electroless deposited thinly flakelike Ni(OH)2 scaffold film. The electro-sulfurization process yielded the deposition of thin layer Mn-(O/S) composite film on ITO with enhanced pseudocapacitive responses. The electrochemical charge storage measurements also revealed highly stable Ni(OH)2/S@MnO2 supercapattery electrode via the synergistic S@MnO2 pseudocapacitive and scaffolding Ni(OH)2 battery-type, responses. Consequently, the as-grown heterostructure exhibited a capacitance value of 2825 F/g (113.56 mF cm- 2) and with capacity value of 1252 C/g at 1 A/g current density. In the two-electrode mode, a fabricated device encompassing Ni(OH)2/S@MnO2 positive electrode and thermally reduced graphene oxide (TRGO) negative electrode, exhibited comparable areal capacitance (8.7 mF cm- 2), high cell voltage (1.7 V) and areal energy density 3.542 mu Wh cm- 2 at 0.1 mAcm-2 current density. Excellent charge-discharge capacitance retention (87.1 % after 20,000 cycles) and voltage holding strength were also demonstrated by the cell.

Transition metal phosphates (TMP) have been extensively investigated as significant electroactive material for flexible electrochemical energy storage devices because they offer a wide range of chemical compositions for enhanced charge and ion accumulations and can withstand high mechanical deterioration suggesting potential for flexible devices. Herein, we report a redox-active MnO2/NiCo-phosphate layered heterostructure electrode prepared by a two-step solution growth process on flexible conducting Au/PET substrate, and with its physicochemical characteristic buildup studied in detail. Firstly, the electroless deposited underlying NiCo-phosphate presented ultrathin nano-spherical particles with high roughness, enabling the exhibition of superior 188 mAh g-1 capacity (1 A g-1) to other TMP (Co/Ni) electrodes. Thereafter, the NiCo-phosphate electrode was decorated with complete coverage of densely stacked interconnected MnO2 nanofiber-with chainlike architecture via electrodeposition process, for enhanced capacitive chemistry. The synergistic features exploited from the structure revealed an enhanced capacity of 268.3 mAh g-1, and capacitance of 1882 F g-1, as well as better cyclability. Furthermore, a hybrid flexible full-cell structure was fabricated using the structure and pristine carbon-based polyaniline (C@PANI) as positive and negative electrodes, respectively to establish viability of the former. The fabricated hybrid cell exhibited optimum areal capacitance, energy density and power density values of 92 mF cm-2, 15.51 mu Wh cm-2 and 0.445 mW cm-2, respectively at 1.0 mA cm-2 current density. Additionally, the cell presented excellent cycling stability and voltage holding strengths with notable 81.9 % (after 15,000 cycles) and 75.5 % (after 48 h floating), respectively and demonstrated real-time practicability.

Molybdenum disulfide (MoS2) has advantageous traits and characteristics that make it suitable for a diverse array of practical applications, such as optoelectronics and gas sensing. Enhancing the surface area of the adsorbent leads to a proportional increase in its performance. Hence, the synthesized two-electrode electrodeposited MoS2 (ED-MoS2) thin films were microstructurally characterized to investigate its surface modulation for suitable enhancement in its applicative properties. The characterization shows that the surface properties of the deposited film can easily be modulated to favor its needs and can be done by simply varying its electrodeposition parameters, such as growth period and voltage supplied. In addition, persistent n-type conductivity of intrinsic MoS2 makes it challenging to achieve p-type conductivity. By simply varying the cathodic potential, the challenge of obtaining p-type MoS2 thin films was solved. The photoelectrochemical cell measurements revealed that lower cathodic potentials (1.15-1.35 V) favored the growth of p-type MoS2 layers while the growth of n-type MoS layers was achieved at the higher cathodic potential.

Negatrodes with wide negative operating voltage, high electrochemical storage capacity, and intrinsic metal ion intercalation abilities are vital to the continuous development of storage devices with simultaneous energy and power density improvement. Herein, we report binder-less coating of non-stoichiometric vacancy-implanted Nb2O5-x as carbon additive-free negatrode on FTO substrate for asymmetric supercapacitor and sodium ion capacitor applications. The negatrode was fabricated through vacuum-less and low-temperature solvothermal-assisted electro-coating technique and yielded several orders of enhancement in its areal capacitance and retained ca. 90 % of its capacity after 5000 cycles of charge-discharge in aqueous Na+ electrolyte. The solvothermal treated electro-coated electrode (STT_Nb2O5-x) achieved an areal capacitance of 22.58 mF/cm2, which was far higher than those of hydrothermal-treated electro-coated HTT_Nb2O5 and Nb2O5 electrodes. The solvothermal treatment simultaneously enhanced the electro-coated samples' impedance properties and mass load through oxygen vacancy implantation and re-crystallization of the electro-coated Nb2O5 layer, respectively. This study presented a facile and energy-efficient technique of direct coating of defect-enhanced pseudocapacitive nanomaterials for the fabrication of electrochemical storage devices.

Nanocrystalline spinel CoFe2O4 materials have been successfully synthesized by a facile force-driven chemical hydrolysis technique, and the impacts of varying post-synthesis annealing temperature on their morphological, structural, and electrochemical properties have been investigated. Microstructural investigation revealed the formation of a spinel cubic structure of a typical CoFe2O4 nanoparticle, which showed enhanced microstructural properties upon increasing annealing temperature. The optimally improved microstructure, coupled with the exhibition of favorable electrochemical and electrical properties of the CoFe2O4 sample annealed at 800 °C, resulted in an enhanced pseudocapacitive charge storage performance with maximum specific capacitance and capacity values of 756.5 Fg−1 and 57.16 mAhg−1. The presence of interstitial sites enabled fast and efficient ion transport and diffusion attributes for the high electrochemical charge storage outputs. The obtained results suggest that the effectiveness of CoFe2O4 as electrode materials for electrochemical energy storage depends on its microstructural build-up via thermal treatment variations.

Herein, we report the implantation of oxygen vacancy dopants in electro-coated WO3 thin film electrodes for enhanced energy and environmental applications. The implantation method involved partial de-oxidation in sodium borohydride to introduce oxygen vacancies into the WO3 electrodes. The doped WO 3-x demonstrated a significantly lowered average band energy of 2.11 eV, indicating its ability to absorb over 75 % of the visible light spectrum. Moreover, a thin film asymmetric supercapacitor assembled with WO 3-x negatrode demonstrated an improved areal capacitance of 1.15 mFcm- 2 and energy density of 0.33 mu Whcm-2 while consuming power at 17.50 mu Wcm- 2 when cycled at 25 mu Acm- 2 . Our solution-processed technique allows for controllable vacancy implantation and binder-free coating of WO 3-x on various substrates. It significantly reduces the processing time and requires low energy consumption, making it a practical and efficient method for enhancing the overall photo-conversion and energy storage performances of WO3-based electrodes.

Monolayer Molybdenum Disulfide (MoS2) exhibits a direct bandgap characterized by strong visible photoluminescence, high on/off ratio, high optical transparency, low dissipation rate, and light absorption in a wide energy spectrum. The influence of different deposition voltages and durations on the optical and photoluminescent characteristics was investigated using Raman spectroscopy, UV–visible spectrophotometry, and photoluminescence spectroscopy. All samples were analyzed for optical properties to confirm their suitability for optoelectronics. The energy band gap and Urbach energy (band tail width) of all films were 1.87 to 2.52 eV and 0.31 to 0.49 eV, respectively. The findings reveal a correlation between enhanced absorption properties and a decrease in the bandgap of the semiconducting film layers, implying the potential utility of the deposited films as efficient solar absorbers. Furthermore, the improved transmittance observed within the visible wavelength range suggests their applicability as effective window layers in thin-film photodiodes. It was established that varying the voltage and time of deposition alone can enhance the optoelectronic performance of the material in any device.

The Co@ZnO thin film deposited on glass substrate with dopant contents of cobalt ranging from 0 to 10 % were fabricated using spray pyrolysis coating method. The prepared nanocomposite thin film was characterized by scanning electron microscopy, X-ray diffraction, UV-vis and Raman spectroscopy. Some surfaces structural probing of the deposited samples confirmed nanolamination of hexagonal wurtzite phase of ZnO with no other impurity phases and high adherence on the soda lime glass substrate. Average grain sizes (56-43 nm) and lattice strain of the films were found to be tailored with the variation of Co-dopant content, signifying phonon confinement or defect/disorder caused by the Co-dopant impurity on the ZnO host particle owing to the impurity levels and oxygen vacancy states. The film demonstrated high optical transmittance with enhanced photoabsorbtion and narrow optical band gap (3.24-2.64 eV) with increasing Co-dopant content. In evaluating its antibacterial efficacy, the Co@ZnO thin film was tested at different dopant concentration against Bacillus cereus (foodborne pathogen). The result revealed that the films exhibits excellent inhibitory effect on the pathogen, with highest activity obtained at 10 % Co@ZnO. Furthermore, a more improved inhibitory activity was recorded when at 10 % Co@ZnO dopant was exposed to UV irradiation.

Energy bands modulations in thin films heterostructure has offered exceptional leads towards the development of photosensing material. In this work, nanostructured metal oxides interfacial electrode structure has been employed to fabricate a highly sensitive ultraviolet (UV) sensor with high responsivity and detectivity. A unique, simple and cost-effective electrodeposition approach was adopted for the growth of the film samples. The interfacial structural effect and optical energy band modulations on the photo-electronic structure and UV detector performance of the structure have been examined. The films had fair transmissions of the visible light spectrum with CuxO dominance in the resulting bilayer structure and a high absorption peak in the ultraviolet (UV) region. The energy band gap redshifted towards the bilayer structure from 3.74-2.67 eV. Charge carriers trapping through surface recombination has been found to reduce from the assistance of ohmic contact formation of the heterostructure. The bilayer film-based photodetector demonstrated enhanced performance with photodetectivity (1.6⨯1011 Jones at 0.068 mWcm-2 power density), attributable to the existence of lower recombination state in the structure, according to the UV sensing study. The study showed that tailoring dissimilar metal oxide semiconducting films to the bilayer (CuxO/NiO) structure can provide excellent UV photodetector performance over single-layer of NiO and CuxO.

Miniaturized energy storage devices are currently gaining attention because of the growing need for portable, implantable, and wearable electronics. Micro-supercapacitors (MSC) have a shorter ionic diffusion path and may perform better than traditional electrochemical energy storage system because they are manufactured on a single substrate and can be easily integrated with other devices. In the meanwhile, they are easily produced and incorporated into miniaturized on-chip electronics, and this suggests that they could supply long-lasting power for sophisticated microelectronic systems. Although the subject of rigid MSC has been the subject of numerous influential reviews to date, no work has systematically compiled the evolution of Flexible MSCs with unique storage features, from microelectrode fabrication to functionalization and integration with various solar energy harvesters. This review therefore provided important characteristics and exciting prospects for the outstanding performance of flexible MSCs through a rigorous examination of the current state of advancement and challenges with flexible integrated photocharging power systems.

The field of myconanotechnology has gained significant attention recently due to the potential uses of biosynthesized nanoparticles derived from macrofungi, specifically mushrooms. Because of their high secretion of biomolecules and enzymes, which can function as efficient reducing and stabilizing agents for the biogenic synthesis of various nanoparticles through extracellular or intracellular procedures, the usage of mushroom extracts is thought to be noteworthy. The high yields, enhanced enzymatic activities, great tolerance to heavy metals, and easy recovery process of the nanoparticles generated by this method have proven superior to those produced using other biogenic methods. These exceptional attributes facilitate more research into their potential uses in the industrial, biomedical, agricultural, and environmental fields. This review specifically provides a critical overview on the mushroom biology, mushroom-mediated nanoparticles synthesis, types, characteristics and exciting applications.