Fabrication and Photocatalytic Applications of Perovskite Materials with Special Emphasis on Alkali-Metal-Based Niobates and Tantalates

Engineering of LiTaO3 Nanoparticles by Flame Spray Pyrolysis: Understanding In Situ Li-Incorporation into the Ta2O5 Lattice

Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15-25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice.

Solar Photocatalytic Activity of Ba-Doped ZnO Nanoparticles: The Role of Surface Hydrophilicity

Bare zinc oxide (ZnO) and Ba-doped ZnO (BZO) samples were prepared by using a simple precipitation method. The effects of Barium doping on the structural, morphological, and optoelectronic properties, as well as on the physico-chemical features of the surface were investigated and correlated with the observed photocatalytic activity under natural solar irradiation. The incorporation of Ba2+ ions into the ZnO structure increased the surface area by ca. 14 times and enhanced the hydrophilicity with respect to the bare sample, as demonstrated by infrared spectroscopy and contact angle measurements. The surface hydrophilicity was correlated with the enhanced defectivity of the doped sample, as indicated by X-ray diffraction, Raman, and fluorescence spectroscopies. The resulting higher affinity with water was, for the first time, invoked as an important factor justifying the superior photocatalytic performance of BZO compared to the undoped one, in addition to the slightly higher separation of the photoproduced pairs, an effect that has already been reported in literature. In particular, observed kinetic constants values of 8∙10-3 and 11.3∙10-3 min-1 were determined for the ZnO and BZO samples, respectively, by assuming first order kinetics. Importantly, Ba doping suppressed photocorrosion and increased the stability of the BZO sample under irradiation, making it a promising photocatalyst for the abatement of toxic species.

Type-II CuFe2O4/Graphitic Carbon Nitride Heterojunctions for High-Efficiency Photocatalytic and Electrocatalytic Hydrogen Generation

Solar water splitting has emerged as an urgent imperative as hydrogen emerges as an increasingly important form of energy storage. g-C₃N₄ is an ideal candidate for photocatalytic water splitting as a result of the excellent alignment of its band edges with water redox potentials. To mitigate electron-hole recombination that has limited the performance of g-C₃N₄, we have developed a semiconductor heterostructure of g-C₃N₄ with CuFe₂O₄ nanoparticles (NPs) as a highly efficient photocatalyst. Visible-light-driven photocatalytic properties of CuFe₂O₄/g-C₃N₄ heterostructures with different CuFe₂O₄ loadings have been examined with two sacrificial agents. An up to 2.5-fold enhancement in catalytic efficiency is observed for CuFe₂O₄/g-C₃N₄ heterostructures over g-C₃N₄ nanosheets alone with the apparent quantum yield of H₂ production approaching 25%. The improved photocatalytic activity of the heterostructures suggests that introducing CuFe₂O₄ NPs provides more active sites and reduces electron-hole recombination. The g-C₃N₄/CuFe₂O₄ heterostructures furthermore show enhanced electrocatalytic HER activity as compared to the individual components as a result of which by making heterostructures g-C₃N₄ with CuFe₂O₄ increased the active catalytic surface for the electrocatalytic water splitting reaction. The enhanced faradaic efficiency of the prepared heterostructures makes it a potential candidate for efficient hydrogen generation. Nevertheless, the designed heterostructure materials exhibited significant photo- and electrocatalytic activity toward the HER, which demonstrates a method for methodically enhancing catalytic performance by creating heterostructures with the best energetic offsets.

Metal-Organic Precursor Synthesis, Structural Characterization, and Multiferroic Properties of GdFeO3 Nanoparticles

GdFeO₃ nanoparticles were fabricated by a facile metal-organic precursor method using citric acid as a complexing agent. The phase purity and structural analysis by powder X-ray diffraction and FTIR studies indicates that the material is highly crystalline with an orthorhombic structure. Electron microscopic (TEM and SEM) studies of rare earth ferrites reveal worm-shaped nanoparticles with an average grain size of 95 nm. The high-resolution TEM study provides an insightful image, which shows an interplanar spacing of approximately 0.12 nm that corresponds to the (112) crystalline plane. A high surface area of 231.5 m² g^-1 has been achieved with a mesoporous texture, which in turn gives a high dielectric constant. Well-defined hysteresis is obtained with a saturation magnetization of 17.5 emu g^-1, remanent magnetization of 3.9 emu g^-1, and coercive field of -446 Oe. Room-temperature ferroelectricity in GdFeO₃ nanoparticles has been found for the first time with no leaky current and hence may be used in multistate memory devices.

A review on the applications of zinc tungstate (ZnWO4) photocatalyst for wastewater treatment

The monoclinic wolframite-phase structure of ZnWO₄ materials has been frequently synthesised, characterised, and applied in optical fibres, environmental decontamination, electrochemistry, photonics, catalysis, and not limited to magnetic applications. However, the problems of crystal growth conditions and mechanisms, growth, the crystal quality, stability, and the role of synthesis parameters of ZnWO₄ nanoparticles remain a challenge limiting its commercial applications. This review presents recent advances of ZnWO₄ as an advanced multi-functional material for Industrial wastewater treatment. The review also examines the influence of the synthesis parameters on the properties of ZnWO₄ and provides insight into new perspectives on ZnWO₄-based photocatalyst. Many researches have shown significant improvement in the efficiency of ZnWO₄ by mixing with polymers and doping with metals, nonmetals, and other nanoparticles. The review also provides information on the mechanism of doping ZnWO₄ with metals, non-metals, metalloids, metals oxides, and polymers based on different synthesis methods for bandgap reduction and extension of its photocatalytic activity to the visible region. The doped ZnWO₄ photocatalyst was a more effective and environmentally friendly material for removing organic and inorganic contaminants in industrial wastewater than ordinary ZnWO₄ nanocrystalline under suitable growth conditions.

Chemical fabrication, structural characterization and photocatalytic water splitting application of Sr-doped SnO2nanoparticles

Semiconductor photocatalysis has gained considerable attention in recent years due to their enabling nature to convert solar energy into fuels of renewable hydrocarbon. However, many of them suffer from some drawbacks like the inability to visible light irradiation and wide band gaps. Herein, we have synthesized monophasic strontium (Sr) doped SnO₂nanoparticles by a cost-effective and environmental friendly hydrothermal method. As-synthesized nanoparticles showed rutile crystalline structure with irregular and rough cubical shape and no other elemental impurities. Sr-doped SnO₂nanoparticles show a constant decrease in bandgap with increasing dopant concentration, which is estimated for excellent photocatalytic activity. The photocatalytic water splitting of as-prepared Sr-doped SnO₂nanoparticles for H₂generation shows a large influence of the increasing dopant concentration related to the narrowing bandgap on H₂generation rate. Hence, the tunable bandgap with adjusted dopant concentration indicates that band gap tuning through doping for produced nanostructures may open up a new opportunities for photocatalytic and other optoelectronic applications.

Self-Assembled Interwoven Nanohierarchitectures of NaNbO3 and NaNb1-x Ta x O3 (0.05 ≤ x ≤ 0.20): Synthesis, Structural Characterization, Photocatalytic Applications, and Dielectric Properties

Dependence on fossil fuels for energy purposes leads to the global energy crises due to the nonrenewable nature and high CO₂ production for environmental pollution. Therefore, new ways of nanocatalysis for environmental remediation and sustainable energy resources are being explored. Herein, we report a facile surfactant free, low temperature, and environmentally benign hydrothermal route for development of pure and (5, 10, 15, and 20 mol %) Ta-doped horizontally and vertically interwoven NaNbO₃ nanohierarchitecture photocatalysts. To the best of our knowledge, such a type of hierarchical structure of NaNbO₃ has never been reported before, and changes in the microstructure of these nanoarchitectures on Ta-doping has also been examined for the first time. As-synthesized nanostructures were characterized by different techniques including X-ray diffraction analysis, electron microscopic studies, X-ray photoelectron spectroscopic studies, etc. Ta-doping considerably affects the microstructure of the nanohierarchitectures of NaNbO₃, which was analyzed by FESEM analysis. The UV-visible diffused reflectance spectroscopy study shows considerable change in the band gap of as-synthesized nanostructures and was found to be ranging from 2.8 to 3.5 eV in pure and different mole % Ta-doped NaNbO₃. With an increase in dopant concentration, the surface area increases and was equal to 5.8, 6.8, 7.0, 9.2, and 9.7 m²/g for pure and 5, 10, 15, and 20 mol % Ta-doped NaNbO₃, respectively. Photocatalytic activity toward the degradation of methylene blue dye and H₂ evolution reaction shows the highest activity (89% dye removal and 21.4 mmol g^-1 catalyst H₂ evolution) for the 10 mol % NaNbO₃ nanostructure which was attributed to a change in the conduction band maximum of the material. At 100 °C and 500 kHz, the dielectric constants of pure and 5, 10, 15, and 20 mol % Ta-doped NaNbO₃ were found to be 111, 510, 491, 488, and 187, respectively. The current study provides the rational insight into the design of nanohierarchitectures and how microstructure affects different properties of the material upon doping.

Modified, Solvothermally Derived Cr-doped SnO2 Nanostructures for Enhanced Photocatalytic and Electrochemical Water-Splitting Applications

Cr-doped SnO₂ nanostructures with a dopant concentration ranging from 1 to 5% have been successfully prepared using low-temperature modified solvothermal synthesis. The as-prepared nanoparticles showed a rutile tetragonal structure with a rough undefined morphology having no other elemental impurities. The particle shape and size, band gap, and specific surface area of the samples were investigated by scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, UV-visible diffused reflectance spectroscopy, and Brunauer-Emmett-Teller surface area studies. The optical band gap was found in the range of 3.23-3.67 eV and the specific surface area was in the range of 108-225 m²/g, which contributes to the significantly enhanced photocatalytic and electrochemical performance. Photocatalytic H₂ generation of as-prepared Cr-doped SnO₂ nanostructures showed improved effect of the increasing dopant concentration with narrowing of the band gap. Electrochemical water-splitting studies also stressed upon the superiority of Cr-doped SnO₂ nanostructures over pristine SnO₂ toward hydrogen evolution reaction and oxygen evolution reaction responses.

Photocatalysis and perovskite oxide-based materials: a remedy for a clean and sustainable future

The massive use of non-renewable energy resources by humankind to fulfill their energy demands is causing severe environmental issues. Photocatalysis is considered one of the potential solutions for a clean and sustainable future because of its cleanliness, inexhaustibility, efficiency, and cost-effectiveness. Significant efforts have been made to design highly proficient photocatalyst materials for various applications such as water pollutant degradation, water splitting, CO2 reduction, and nitrogen fixation. Perovskite photocatalyst materials are gained special attention due to their exceptional properties because of their flexibility in chemical composition, structure, bandgap, oxidation states, and valence states. The current review is focused on perovskite materials and their applications in photocatalysis. Special attention has been given to the structural, stoichiometric, and compositional flexibility of perovskite photocatalyst materials. The photocatalytic activity of perovskite materials in different photocatalysis applications is also discussed. Various mechanisms involved in photocatalysis application from wastewater treatment to hydrogen production are also provided. The key objective of this review is to encapsulate the role of perovskite materials in photocatalysis along with their fundamental properties to provide valuable insight for addressing future environmental challenges.

Rare earth doped metal oxide nanoparticles for photocatalysis: a perspective

Metal oxides are well-known materials that have been considered as the prominent photocatalysts. Photocatalysis is a promising way to address the environmental issues which are caused by fossil fuel the combustion and industrial pollutants. Lot of efforts such as doping of metal oxides with metals, non-metals have been made to enhance their photocatalytic activity. More specifically, in this review we have discussed detailed synthesis procedures of rare earth doped metal oxides performed in the past decades. The advantage of doping metal oxides with rare earth metals is that they readily combine with functional groups due to the 4f vacant orbitals. Moreover, doping rare earth metals causes absorbance shift to the visible region of the electromagnetic spectrum which results to show prominent photocatalysis in this region. The effect of rare earth doping on different parameters of metal oxides such as band gap and charge carrier recombination rate has been made in great details. In perspective section, we have given a brief description about how researchers can improve the photocatalytic efficiencies of different metal oxides in coming future. The strategies and outcomes outlined in this review are expected to stimulate the search for a whole new set of rare earth doped metal oxides for efficient photocatalytic applications.

Silver-doped SnO2 nanostructures for photocatalytic water splitting and catalytic nitrophenol reduction

Driven by the quest of renewable and clean energy sources, researchers around the globe are seeking solutions to replace non-renewable fossil fuels to meet the ever-increasing energy supply requirements and solve the relevant environment concerns.

Multifunctional Efficacy of Environmentally Benign Silver Nanospheres for Organic Transformation, Photocatalysis, and Water Remediation

Highly crystalline and monophasic silver nanospheres with a high specific surface area of 57 m²/g have been synthesized by an environmentally benign rapid chemical reduction using l-alanine for catalytic transformation, photocatalytic degradation, and bacterial disinfection, which can provide an ample strategy for water remediation. Electron microscopic analysis confirms the spherical morphology of as-prepared silver nanoparticles with an average grain size of 20 nm. Silver nanospheres showed excellent catalytic activity for the catalytic hydrogenation and conversion (95.6%) of 4-nitrophenol to 4-aminophenol. Significant photocatalytic degradation proficiency was also shown for methylene blue (94.5%) and rhodamine B (96.3%) dyes under solar irradiation. The antibacterial behavior of Ala-Ag nanospheres was demonstrated through the disk diffusion antibacterial assay against Gram-positive (Escherichia coli) and Gram-negative (Staphylococcus aureus) bacteria. Multifunctional efficiency of as-prepared Ala-Ag nanospheres for water remediation has also been established.

Development of Cuboidal KNbO3@α-Fe2O3 Hybrid Nanostructures for Improved Photocatalytic and Photoelectrocatalytic Applications

Monophasic and hybrid nanostructures of KNbO₃ and α-Fe₂O₃ have been prepared using a hydrothermal process for photoelectrocatalytic and photocatalytic applications. Powder X-ray diffraction studies showed the formation of KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ with average grain sizes of 18.3, 11.5, and 26.1 nm and Brunauer-Emmett-Teller (BET) specific surface areas of 4, 100, and 20 m²/gm, respectively. Under simulated solar irradiation, the as-prepared heterostructure shows enhanced photoelectrocatalytic oxygen evolution reaction (OER) activity compared to pristine KNbO₃ and α-Fe₂O₃. Significant photocatalytic activity of as-synthesized KNbO₃/α-Fe₂O₃ heterostructure photocatalyst was obtained for removal of methylene blue organic dye under visible light, and the percentage activity was found to be 11, 49, and 89% for KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ photocatalysts, respectively. The dielectric constant was found to be 250.2, 65.2, and 251.5 for KNbO₃, α-Fe₂O₃, and KNbO₃/α-Fe₂O₃ heterostructure, respectively, at 50 °C and 500 kHz frequency.

Luminescence properties and energy transfer of Tb3+, Eu3+ co-doped YTaO4 phosphors obtained via sol-gel combustion process

Tantalate is considered as a valuable and efficient luminescence host because of its intense absorption in the ultraviolet area and excellent chemical properties. In this work, a series of pure YTaO4:Eu3+ and/or Tb3+ crystals were prepared via a sol-gel combustion method. The morphology, structure, and optical properties of the samples were discussed in detail. The Eu3+, Tb3+ co-doped YTaO4 samples are consisted of small spherical particles of around 18 nm. The prepared YTaO4:Tb3+ and/or Eu3+ samples exhibit the characteristic wide excitation band around 210-300 nm, the characteristic narrow red emission of Eu3+ (5D0 → 7F2) transitions and green emission of the Tb3+ (5D4 → 7F5) transitions when excited by UV light. It is focused on the energy transfer processes from the YTaO4 to Tb3+ as well as Eu3+ ions and from Tb3+ to Eu3+ ions of YTaO4:Eu3+/Tb3+ phosphors. Color-tunable emissions are realized through adjusting the types of rare earth ion (Eu3+ and Tb3+) and relative doping concentrations excited by a single wavelength. That is to say, the obtained Tb3+ and Eu3+ co-doped YTaO4 phosphors have a promising prospect in lasers, white light diodes (WLED), fluorescent lamp, and field emission display devices, etc.

Enhanced Solar Light Photocatalytic Activity of Ag Doped TiO2-Ag3PO4 Composites

Composites comprised of Ag₃PO₄ and bare TiO₂ (TiO₂@Ag₃PO₄) or silver doped TiO₂ (Ag@TiO₂–Ag₃PO₄) have been synthesized by coupling sol–gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis. The optoelectronic and structural features of the samples have been related to their photocatalytic activity for the degradation of 4–nitrophenol under solar and UV light irradiation. Coupling Ag₃PO₄ with silver doped TiO₂ mitigates photocorrosion of the Ag₃PO₄ counterpart, and remarkably improves the photocatalytic activity under solar light irradiation with respect to the components, to the TiO₂–Ag₃PO₄ sample, and to the benchmark TiO₂ Evonik P25. These features open the route to future applications of this material in the field of environmental remediation.

High-Surface-Area Sodium Tantalate Nanoparticles with Enhanced Photocatalytic and Electrical Properties Prepared through Polymeric Citrate Precursor Route

NaTaO₃ nanoparticles with a high surface area of 46.2 m²/g have been successfully synthesized using a polymeric citrate precursor route. As-prepared nanoparticles were extensively characterized by X-ray diffraction, Fourier transform infrared, transmission emission microscopy, and scanning electron microscopy studies for the analysis of phase purity, crystallinity, and morphology. NaTaO₃ nanoparticles show efficient photo-induced removal of the methylene blue dye under sunlight, which were confirmed by using liquid chromatography-mass spectroscopy. 86% dye has been degraded in 200 min at neutral pH, whereas the same amount of dye was decolorized in only 80 min at alkaline pH. Also, the dielectric behavior of the as-prepared nanoparticles at different annealing temperatures was explained by the Maxwell-Wagner polarization mechanism. At 500, 600, and 700 °C annealing temperatures, the dielectric constant and dielectric loss at 500 kHz for the samples were found to be 21.5, 18, and 16 and 0.012, 0.022, and 0.029, respectively. The unsaturated hysteresis loop shows weak ferroelectric behavior of NaTaO₃ nanoparticles with remanent and saturation polarizations of 0.0013 and 0.21 μC/cm², respectively, and S-E hysteresis shows a bipolar strain of 0.10%.

Doping Strontium into Neodymium Manganites Nanocomposites for Enhanced Visible light Driven Photocatalysis

Nd_1-xSr_xMnO₃ nanocomposites perovskites were synthesized using sol gel method at different Sr content x = 0.3, 0.5, 0.7, and 0.9. The photocatalytic performance of the Nd_1-xSr_xMnO₃ nanocomposites for photodegradation of Acridine orange dye (AO) was evaluated over visible light illumination. The single phase of orthorhombic pbnm was formed for x = 0.3 and 0.5; however monoclinic and orthorhombic were observed at x = 0.7 and 0.9. The Energy gap of the Nd_1-xSr_xMnO₃ nanocomposites were estimated for all concentrations to be in the range of 3 ± 0.05 eV. The photocatalytic efficiency of Nd_0.3Sr_0.7MnO₃ nanocomposite was 95% of the initial AO dye concentration within 3 h illumination time. The linear increase of the photodegradation rate was found in our samples as a result of the increase of Sr contents from 0.3 to 0.7wt %. Interestingly, the Nd_0.3Sr_0.7MnO₃ content has the highest degradation rate of AO which is two times faster than undoped NdMnO₃. This superior behavior in photocatalytic activity of Nd_0.3Sr_0.7MnO₃ nanocomposite emerges from large surface area, structural anisotropy, and small particle size. These findings shows convincingly that the Nd_1-xSr_xMnO₃ photocatalysts possess great promise for visible light driven photodegradation of AO dye.

Sodium Tantalate Photocatalysts Doped with Metal Cations: Why Are They Active for Water Splitting?

Sodium tantalate (NaTaO3 ) is the first semiconductor photocatalyst that produces hydrogen-oxygen mixed bubbles in the overall water splitting reaction, when appropriately doped with metal cations. A series of studies are reviewed herein to answer the question of why doping with metal cations raised the quantum efficiency of the reaction. Infrared absorption of band-gap-excited photocatalysts demonstrated that cation doping reduced the electron-hole recombination rate and the steady-state population of charge carriers accordingly increased. In-depth studies are focused on Sr cations incorporated through solid-state, flux, and hydrothermal reactions. The recombination rate was reduced when Ta cations were exchanged with Sr cations. Sodium cations were simultaneously exchanged to balance the cationic and anionic charges with no need for creating oxygen anion vacancies. NaTaO3 Sr(Sr1/3 Ta2/3 )O3 solid solution was formed as a result of the simultaneous doping. In addition to doping at the appropriate sites, the intraparticle distribution of Sr cations played an essential role to reduce the recombination rate. Strontium cations segregated to produce graded composition from the Sr-rich surface to the Sr-poor core. The bottom of the conduction band was raised at the Sr-rich surface and the excited electrons were driven to the Sr-poor core, leaving holes at the surface. However, the graded composition had a dual purpose; the excited electron population increased and its fractional contribution to the surface reaction decreased.

Electrocatalytic and Enhanced Photocatalytic Applications of Sodium Niobate Nanoparticles Developed by Citrate Precursor Route

Development of cost effective and efficient electrocatalysts is crucial to generate H2 as an alternative source of energy. However, expensive noble metal based electrocatalysts show best electrocatalytic performances which acts as main bottle-neck for commercial application. Therefore, non-precious electrocatalysts have become important for hydrogen and oxygen evolution reactions. Herein, we report the synthesis of high surface area (35 m2/g) sodium niobate nanoparticles by citrate precursor method. These nanoparticles were characterized by different techniques like X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Electrocatalytic properties of cost-effective sodium niobate nanoparticles were investigated for HER and OER in 0.5 M KOH electrolyte using Ag/AgCl as reference electrode. The sodium niobate electrode showed significant current density for both OER (≈2.7 mA/cm2) and HER (≈0.7 mA/cm2) with onset potential of 0.9 V for OER and 0.6 V for HER. As-prepared sodium niobate nanoparticles show enhanced photocatalytic property (86% removal) towards the degradation of rose Bengal dye. Dielectric behaviour at different sintering temperatures was explained by Koop's theory and Maxwell-Wagner mechanism. The dielectric constants of 41 and 38.5 and the dielectric losses of 0.04 and 0.025 were observed for the samples sintered at 500 °C and 700 °C, respectively at 500 kHz. Conductivity of the samples was understood by using power law fit.

Electrocatalytic and Enhanced Photocatalytic Applications of Sodium Niobate Nanoparticles Developed by Citrate Precursor Route

Development of cost effective and efficient electrocatalysts is crucial to generate H₂ as an alternative source of energy. However, expensive noble metal based electrocatalysts show best electrocatalytic performances which acts as main bottle-neck for commercial application. Therefore, non-precious electrocatalysts have become important for hydrogen and oxygen evolution reactions. Herein, we report the synthesis of high surface area (35 m²/g) sodium niobate nanoparticles by citrate precursor method. These nanoparticles were characterized by different techniques like X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Electrocatalytic properties of cost-effective sodium niobate nanoparticles were investigated for HER and OER in 0.5 M KOH electrolyte using Ag/AgCl as reference electrode. The sodium niobate electrode showed significant current density for both OER (≈2.7 mA/cm²) and HER (≈0.7 mA/cm²) with onset potential of 0.9 V for OER and 0.6 V for HER. As-prepared sodium niobate nanoparticles show enhanced photocatalytic property (86% removal) towards the degradation of rose Bengal dye. Dielectric behaviour at different sintering temperatures was explained by Koop's theory and Maxwell-Wagner mechanism. The dielectric constants of 41 and 38.5 and the dielectric losses of 0.04 and 0.025 were observed for the samples sintered at 500 °C and 700 °C, respectively at 500 kHz. Conductivity of the samples was understood by using power law fit.