Eco-friendly mixed metal (Mg-Ni) ferrite nanosheets for efficient electrocatalytic water splitting.

Eco-friendly and cost-effective catalysts with multiple active sites, large surface area, high stability and catalytic activity are highly desired for efficient water splitting as a sustainable green energy source. Within this line, a facile synthetic approach based on solventless thermolysis was employed for the simple and tunable synthesis of Ni1-xMgxFe2O4 (0 ≤ x ≤ 1) nanosheets. The characterization of nanosheets (via p-XRD, EDX, SEM, TEM, HRTEM, and SAED) revealed that the pristine ferrites (NiFe2O4 and MgFe2O4), and their solid solutions maintain the same cubic symmetry throughout the composition regulation. Elucidation of the electrochemical performance of the nanoferrite solid solutions showed that by tuning the local chemical environment of Ni in NiFe2O4 via Mg substitution, the intrinsic catalytic activity was enhanced. Evidently, the optimized Ni0.4Mg0.6Fe2O4 catalyst showed drastically enhanced HER activity with a much lower overpotential of 121 mV compared to the pristine NiFe2O4 catalyst. Moreover, Ni0.2Mg0.8Fe2O4 catalyst exhibited the best OER performance with a low overpotential of 284 mV at 10 mA/cm2 in 1 M KOH. This enhanced electrocatalytic activity could be due to improved electronic conductivity caused by the partial substitution of Ni2+ by Mg2+ in the NiFe2O4 matrix as well as the synergistic effect in the Mg-substituted NiFe2O4. Our results suggest a feasible route for developing earth-abundant metal oxide-based electrocatalysts for future water electrolysis applications.

Molecular Precursor Routes for Ag-Based Metallic, Intermetallic, and Metal Sulfide Nanoparticles: Their Comparative ORR Activity Trend at Solid|Liquid and Liquid|Liquid Interfaces.

The electrochemical conversion of oxygen to water is a crucial process required for renewable energy production, whereas its first two-electron step produces a versatile chemical and oxidant─hydrogen peroxide. Improving performance and widening the limited selection of the potential catalysts for this reaction is a step toward the implementation of clean-energy technologies. As silver is known as one of the most effective catalysts of oxygen reduction reaction (ORR), we have designed a suitable molecular precursor pathway for the selective synthesis of metallic (Ag), intermetallic (Ag3Sb), and binary or ternary metal sulfide (Ag2S and AgSbS2) nanomaterials by judicious control of reaction conditions. The decomposition of xanthate precursors under different reaction conditions in colloidal synthesis indicates that carbon-sulfur bond cleavage yields the respective metal sulfide nanomaterials. This is not the case in the presence of trioctylphosphine when the metal-sulfur bond is broken. The synthesized nanomaterials were applied as catalysts of oxygen reduction at the liquid-liquid and solid-liquid interfaces. Ag exhibits the best performance for electrochemical oxygen reduction, whereas the electrocatalytic performance of Ag and Ag3Sb is comparable for peroxide reduction in an alkaline medium. Scanning electrochemical microscopy (SECM) analysis indicates that a flexible 2-electron to 4-electron ORR pathway has been achieved by transforming metallic Ag into intermetallic Ag3Sb.

Precursor Engineering for the Synthesis of Mixed Anionic Metal (Cu, Mn) Chalcogenide Nanomaterials via Solvent-Less Synthesis.

Metal-organic ligands with mixed chalcogenides are potential compounds for the preparation of mixed anionic metal chalcogenide alloys. However, only a few of such ligands are known, and their complexes are not well explored. We have prepared homo- and hetero-dichalcogenoimidodiphosphinate [(EE'PiPr2NH)] (E, E' = Se, Se; S, S; S, Se) complexes of manganese and copper through metathetical reactions. The X-ray single crystal structure of [Mn{(SePiPr2)2N}2] 1 revealed a triclinic crystal system, with a MnSe4 core unit, whereas the crystal structure determination of [Mn{(SPiPr2)(SePiPr2)N}2] 2 indicated a triclinic crystal system with a Mn(S/Se)2 unit. Both metal centers are tetrahedral, with two deprotonated bidentate ligands forming the coordination sphere. The free ligand was found to exhibit a gauche configuration in the solid state. The energies of the various rotamers of dithio-analogue were studied by DFT calculations. The decomposition behavior of complexes with homo- and heterochalcogenides was investigated, and the complexes were employed as single-source precursors to generate manganese and copper chalcogenides through solvent-less melt reactions between 500 and 550 °C. The deposited powders were characterized by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), transmission electron microscopy (TEM), and elemental mapping. MnS, MnSe2, and MnSSe phases were obtained from the decomposition of respective manganese complexes. In contrast, the decomposition of copper-based complexes yielded Cu2-xSe and the sulfur-doped Cu3Se2 phase from seleno- and mixed thio/seleno-complexes of Cu, respectively. The morphology ranged from random sheet-like structures to agglomerated platelets, while the selected area electron diffraction (SAED) revealed the crystalline nature of the materials. Depending on the nature of the complex and the temperature, different amounts of phosphorus were present as an impurity in the synthesized products.

Tuning composition of CuCo2S4-NiCo2S4 solid solutions via solvent-less pyrolysis of molecular precursors for efficient supercapacitance and water splitting.

Mixed metal sulfides are increasingly being investigated because of their prospective applications for electrochemical energy storage and conversion. Their high electronic conductivity and high density of redox sites result in significant improvement of their electrochemical properties. Herein, the composition-dependent supercapacitive and water splitting performance of a series of Ni(1-x)Cu x Co2S4 (0.2 ≤ x ≤ 0.8) solid solutions prepared via solvent-less pyrolysis of a mixture of respective metal ethyl xanthate precursors is reported. The use of xanthate precursors resulted in the formation of surface clean nanomaterials at low-temperature. Their structural, compositional, and morphological features were examined by p-XRD, SEM, and EDX analyses. Both supercapacitive and electrocatalytic (HER, OER) properties of the synthesized materials significantly vary with composition (Ni/Cu molar content). However, the optimal composition depends on the application. The highest specific capacitance of 770 F g-1 at a current density of 1 A g-1 was achieved for Ni0.6Cu0.4Co2S4 (NCCS-2). This electrode exhibits capacitance retention (C R) of 67% at 30 A g-1, which is higher than that observed for pristine NiCo2S4 (838 F g-1 at 1 A g-1, 47% C R at 30 A g-1). On the contrary, Ni0.4Cu0.6Co2S4 (NCCS-3) exhibits the lowest overpotential of 124 mV to deliver a current density of 10 mA cm-2. Finally, the best OER activity with an overpotential of 268 mV at 10 mA cm-2 was displayed by Ni0.8Cu0.2Co2S4 (NCCS-1). The prepared electrodes exhibit high stability, as well as durability.

Synergistically enhanced performance of transition-metal doped Ni2P for supercapacitance and overall water splitting.

Cost-effective and readily available catalysts applicable for electrochemical conversion technologies are highly desired. Herein, we report the synthesis of dithiophosphonate complexes of the type [Ni{S2P(OH)(4-CH3OC6H4)}2] (1), [Co{S2P(OC4H9)(4-CH3OC6H4)}3] (2) and [Fe{S2P(OH)(4-CH3OC6H4)}3] (3) and employed them to prepare Ni2P, Co-Ni2P and Fe-Ni2P nanoparticles. Ni2P was formed by a facile hot injection method by decomposing complex 1 in tri-octylphosphine oxide/tri-n-octylphosphine at 300 °C. The prepared Ni2P was doped with Co and Fe employing complexes 2 and 3, respectively, under similar experimental conditions. Doping Ni2P with Co and Fe demonstrated synergistic improvement of Ni2P performance as an electrocatalyst in supercapcitance, hydrogen evololution and oxygen evolution reactions in alkaline medium. Cobalt doping improved the Ni2P charge storage capacity with a supercapacitance of 864 F g-1 at 1 A g-1 current density. Fe doped Ni2P recorded the lowest overpotential of 259 mV to achieve a current density of 10 mA cm-2 and a Tafel slope of 80 mV dec-1 for OER, better than the undoped Ni2P and the benchmark IrO2. Likewise, Fe-doped Ni2P electrode required the lowest overpotential of 68 mV with a Tafel slope of 110 mV dec-1 to attain the same current density for HER. All catalysts showed excellent stability in supercapacitance and overall water splitting reactions, indicating their practical use in energy conversion technologies.

Colloidal synthesis of metal chalcogenide nanomaterials from metal-organic precursors and capping ligand effect on electrocatalytic performance: progress, challenges and future perspectives.

Renewable and sustainable functional nanomaterials, which can be employed in alternative green energy sources, are highly desirable. Transition metal chalcogenides are potential catalysts for processes resulting in energy generation and storage. In order to optimize their catalytic performance, high phase purity and precise control over shape and size are indispensable. Metal-organic precursors with pre-formed bonds between the metal and the chalcogenide atoms are advantageous in synthesizing phase pure transition metal chalcogenides with controlled shape and sizes. This can be achieved by the decomposition of metal-organic precursors in the presence of suitable surfactants/capping agents. However, the recent studies on electrocatalysis at the nanoscale level reveal that the capping agents attached to their surface have a detrimental effect on their efficiency. The removal of surfactants from active sites to obtain bare surface nanoparticles is necessary to enhance catalytic activity. Herein, we have discussed the properties of different metal-organic precursors and the role of surfactants in the colloidal synthesis of metal chalcogenide nanomaterials. Moreover, the effect of surfactants on their electrocatalytic performance, the commonly used strategies for removing surfactants from the surface of nanomaterials and the future perspectives are reviewed.

Scalable synthesis of Cu-Sb-S phases from reactive melts of metal xanthates and effect of cationic manipulation on structural and optical properties.

We report a simple, economical and low temperature route for phase-pure synthesis of two distinct phases of Cu-Sb-S, chalcostibite (CuSbS2) and tetrahedrite (Cu12Sb4S13) nanostructures. Both compounds were prepared by the decomposition of a mixture of bis(O-ethylxanthato)copper(II) and tris(O-ethylxanthato)antimony(III), without the use of solvent or capping ligands. By tuning the molar ratio of copper and antimony xanthates, single-phases of either chalcostibite or tetrahedrite were obtained. The tetrahedrite phase exists in a cubic structure, where the Cu and Sb atoms are present in different coordination environments, and tuning of band gap  energy was investigated by the incorporation of multivalent cationic dopants, i.e. by the formation of Zn-doped tetrahedrites Cu12-xZnxSb4S13 (x = 0.25, 0.5, 0.75, 1, 1.2 and 1.5) and the Bi-doped tetrahedrites Cu12Sb4-xBixS13 (x = 0.08, 0.15, 0.25, 0.32, 0.4 and 0.5). Powder  X-ray diffraction (p-XRD) confirms single-phase of cubic tetrahedrite structures for both of the doped series. The only exception was for Cu12Sb4-xBixS13 with x = 0.5, which showed a secondary phase, implying that this value is above the solubility limit of Bi in Cu12Sb4S13 (12%). A linear increase in the lattice parameter a in both Zn- and Bi-doped tetrahedrite samples was observed with increasing dopant concentration. The estimated elemental compositions from EDX data are in line with the stoichiometric ratio expected for the compounds formed. The morphologies of samples were investigated using SEM and TEM, revealing the formation of smaller particle sizes upon  incorporation of  Zn. Incorporation of Zn or Bi into Cu12Sb4S13 led to an increase in band gap energy. The estimated band gap energies of Cu12-xZnxSb4S13 films ranges from 1.49 to 1.6 eV, while the band gaps of Cu12Sb4-xBixS13 films increases from 1.49 to 1.72 eV with increasing x.

Selective Synthesis of Bismuth or Bismuth Selenide Nanosheets from a Metal Organic Precursor: Investigation of their Catalytic Performance for Water Splitting.

The development of cost-effective, functional materials that can be efficiently used for sustainable energy generation is highly desirable. Herein, a new molecular precursor of bismuth (tris(selenobenzoato)bismuth(III), [Bi(SeOCPh)3]), has been used to prepare selectively Bi or Bi2Se3 nanosheets via a colloidal route by the judicious control of the reaction parameters. The Bi formation mechanism was investigated, and it was observed that the trioctylphosphine (TOP) plays a crucial role in the formation of Bi. Employing the vapor deposition method resulted in the formation of exclusively Bi2Se3 films at different temperatures. The synthesized nanomaterials and films were characterized by p-XRD, TEM, Raman, SEM, EDX, AFM, XPS, and UV-vis spectroscopy. A minimum sheet thickness of 3.6 nm (i.e., a thickness of 8-9 layers) was observed for bismuth, whereas a thickness of 4 nm (i.e., a thickness of 4 layers) was observed for Bi2Se3 nanosheets. XPS showed surface oxidation of both materials and indicated an uncapped surface of Bi, whereas Bi2Se3 had a capping layer of oleylamine, resulting in reduced surface oxidation. The potential of Bi and Bi2Se3 nanosheets was tested for overall water-splitting application. The OER and HER catalytic performances of Bi2Se3 indicate overpotentials of 385 mV at 10 mA cm-2 and 220 mV, with Tafel slopes of 122 and 178 mV dec-1, respectively. In comparison, Bi showed a much lower OER activity (506 mV at 10 mA cm-2) but a slightly better HER (214 mV at 10 mA cm-2) performance. Similarly, Bi2Se3 nanosheets were observed to exhibit cathodic photocurrent in photoelectrocatalytic activity, which indicated their p-type behavior.

Low temperature scalable synthetic approach enabling high bifunctional electrocatalytic performance of NiCo2S4 and CuCo2S4 thiospinels.

Ternary metal sulfides are currently in the spotlight as promising electroactive materials for high-performance energy storage and/or conversion technologies. Extensive research on metal sulfides has indicated that, amongst other factors, the electrochemical properties of the materials are strongly influenced by the synthetic protocol employed. Herein, we report the electrochemical performance of uncapped NiCo2S4 and CuCo2S4 ternary systems prepared via solventless thermolysis of the respective metal ethyl xanthate precursors at 200 and 300 °C. The structural, morphological and compositional properties of the synthesized nanoparticles were examined by powder X-ray diffraction (p-XRD), transmission electron microscopy (TEM), high-resolution TEM, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX) techniques. Electrochemical studies indicate that NiCo2S4 nanoparticles synthesized at 300 °C exhibit superior energy storage characteristics with a high specific capacitance of ca. 2650 F g-1 at 1 mV s-1, as compared to CuCo2S4 nanoparticles, which showcased a specific capacitance of ca. 1700 F g-1 at the same scan rate. At a current density of 0.5 A g-1, NiCo2S4 and CuCo2S4 nanoparticles displayed specific capacitances of 1201 and 475 F g-1, respectively. In contrast, CuCo2S4 nanoparticles presented a higher electrocatalytic activity with low overpotentials of 269 mV for oxygen evolution reaction (OER), and 224 mV for the hydrogen evolution reaction (HER), at 10 mA cm-2. The stability of the catalysts was examined for 2000 cycles in which a negligible change in both OER and HER activities was observed.

Solventless synthesis of nanospinel Ni1-x Co x Fe2O4 (0 ≤ x ≤ 1) solid solutions for efficient electrochemical water splitting and supercapacitance.

The formation of solid solutions represents a robust strategy for modulating the electronic properties and improving the electrochemical performance of spinel ferrites. However, solid solutions have been predominantly prepared via wet chemical routes, which involve the use of harmful and/or expensive chemicals. In the present study, a facile, inexpensive and environmentally benign solventless route is employed for the composition-controlled synthesis of nanoscopic Ni1-x Co x Fe2O4 (0 ≤ x ≤ 1) solid solutions. The physicochemical characterization of the samples was performed by p-XRD, SEM, EDX, XPS, TEM, HRTEM and UV-Vis techniques. A systematic investigation was also carried out to elucidate the electrochemical performance of the prepared nanospinels towards energy generation and storage. Based on the results of CV, GCD, and stability tests, the Ni0.4Co0.6Fe2O4 electrode showed the highest performance for the supercapacitor electrode exhibiting a specific capacitance of 237 F g-1, superior energy density of 10.3 W h kg-1 and a high power density with a peak value of 4208 W kg-1, and 100% of its charge storage capacity was retained after 4000 cycles with 97% coulombic efficiency. For HER, the Ni0.6Co0.4Fe2O4 and CoFe2O4 electrodes showed low overpotentials of 168 and 169 mV, respectively, indicating better catalytic activity. For OER, the Ni0.8Co0.2Fe2O4 electrode exhibited a lower overpotential of 320 mV at a current density of 10 mA cm-2, with a Tafel slope of 79 mV dec-1, demonstrating a fast and efficient process. These results indicated that nanospinel ferrite solid solutions could be employed as promising electrode materials for supercapacitor and water splitting applications.

Direct solvent free synthesis of bare α-NiS, ß-NiS and α-ß-NiS composite as excellent electrocatalysts: Effect of self-capping on supercapacitance and overall water splitting activity.

Nickel sulfide is regarded as a material with tremendous potential for energy storage and conversion applications. However, it exists in a variety of stable compositions and obtaining a pure phase is a challenge. This study demonstrates a potentially scalable, solvent free and phase selective synthesis of uncapped α-NiS, ß-NiS and α-ß-NiS composites using nickel alkyl (ethyl, octyl) xanthate precursors. Phase transformation and morphology were observed by powder-X-ray diffraction (p-XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The comparative efficiency of the synthesized samples was investigated for energy storage and generation applications, in which superior performance was observed for the NiS synthesized from the short chain xanthate complex. A high specific capacitance of 1,940 F/g, 2,150 F/g and 2,250 F/g was observed at 2 mV/s for bare α-NiS, ß-NiS and α-ß-NiS composite respectively. At high current density of 1 A/g, α-NiS showed the highest capacitance of 1,287 F/g, with 100% of Coulombic efficiency and 79% of capacitance retention. In the case of the oxygen evolution reaction (OER), ß-NiS showed an overpotential of 139 mV at a current density of 10 mA/cm2, with a Tafel slope of only 32 mV/dec, showing a fast and efficient process. It was observed that the increase in carbon chain of the synthesized self-capped nickel sulfide nanoparticles decreased the overall efficiency, both for energy storage and energy generation applications.

Electrochemical investigation of uncapped AgBiS2 (schapbachite) synthesized using in situ melts of xanthate precursors.

In this study, a facile and potentially scalable synthesis of AgBiS2 (schapbachite) using melts of metal xanthates is presented; AgBiS2 is both a significant mineral and a technologically important material. This ternary material was synthesized by a novel and low-cost solventless route using simple ethyl xanthate complexes of silver and bismuth. p-XRD analysis indicates that the synthesized ternary material is highly crystalline and belongs to the cubic phase (schapbachite). The electrochemical properties of the material were tested; the potential of the synthesized material for application in charge storage shows a high specific capacitance of 460 F g-1 at 2 mV s-1. A capacitance retention of 83% with a 100% coulombic efficiency was observed after 3000 cycles. The charge storage potential, analysed by fabricating actual symmetrical devices, shows a specific capacitance of 14 F g-1 at 2 mV s-1. An energy density of 26 W h kg-1 and a power density of 3.6 kW kg-1 were observed. Besides, the potential for the oxygen evolution reaction was also studied. An overpotential of 414 mV and a Tafel slope of 134 mV dec-1 were obtained for water oxidation. The fabrication of an electrolyzer cell using the synthesized material as the cathode indicates that a current of 10 mA cm-2 can be achieved at a potential of 1.63 V.

Phase transition in Cu2+x SnS3+y (0 ≤ x ≤ 2; 0 ≤ y ≤ 1) ternary systems synthesized from complexes of coumarin derived thiocarbamate motifs: optical and morphological properties.

Tetragonal Cu2SnS3 and orthorhombic Cu4SnS4 nanocubes were synthesized by a heat up procedure with oleylamine (OLA) and dodecanethiol (DT) acting as both solvent and capping ligands. Both mohite-anorthic and monoclinic phases were obtained from the same variant of precursors mixture, by hot injection synthesis, at 200 and 250 °C. Changing the reaction conditions also leads to the formation of different morphologies. When OLA was used as a solvent, nanosheets or nanocubes were obtained, while the reaction with DT resulted in the formation of particles in the form of nanohexagons. The growth process of copper tin sulphide starts with the formation of Cu+ seeds, followed by the oxidation of Sn2+ to Sn4+. Dodecanethiol was an additional source of sulphur. The overall reaction leads to the formation of either phase pure Cu2SnS3 or Cu4SnS4, depending on the reaction conditions, with band-gap energies of 1.05-1.45 eV, which are in the optimum range for photovoltaic applications.

Structural investigations of SnS1-xSex solid solution synthesized from chalcogeno-carboxylate complexes of organo-tin by colloidal and solvent-less routes.

Tin chalcogenides are important semiconducting materials due to their non-toxic nature, cost effectiveness and layered structure. In this study, a facile synthetic route has been employed for the synthesis of a bis(selenobenzoato)dibutyltin(iv) complex, and used along with the bis(thiobenzoato)dibutyltin(iv) complex, as single source precursors, to prepare binary tin chalcogenides and their solid solution (SnS1-xSex) in the entire range. The synthesis of the solid solution was carried out by colloidal and melt methods. The comparative analysis of the solid solution obtained from both routes indicates that the colloidal method provides superior control over composition. The UV-Vis-NIR analysis showed a gradual change in the band gap, while moving from SnS to SnSe.

Synthesis of chalcopyrite-type and thiospinel minerals/materials by low temperature melts of xanthates.

Xanthate complexes are used in the low temperature atom efficient synthesis of some geological and technologically important ternary compounds. The process involves direct heating of a stoichiometric mixture of the metal xanthate complexes. The reactive melts of the xanthates, generated in the transition state, cleanly decompose to ternary metal sulfides. The method has great potential for the facile scalable synthesis of ternary materials of composition ABX2 (such as AI = Ag, Cu; BIII = Bi, Cr, Fe, In, Sb and X = S) or AB2X4 (AII = Cd, Co, Cu, Ni; BIII = Co, Cr, Ni, Fe, and X = S).

Bis(selenobenzoato)dibutyltin(iv) as a single source precursor for the synthesis of SnSe nanosheets and their photo-electrochemical study for water splitting.

A new organo-tin complex has been synthesized and used as a single source precursor for the synthesis of SnSe nanosheets by the hot injection method and thin films by the aerosol assisted chemical vapor deposition (AACVD) method. The films were deposited on glass substrates at three different temperatures. The textural quality and preferential growth were found to be significantly altered by changes in the deposition temperature. Oleylamine capped nanosheets and the as-deposited thin films by AACVD were characterized by powder X-ray diffraction (p-XRD) and microscopic techniques. The thin films were also studied by Raman spectroscopy. The stoichiometry is marginally affected by temperature, and all films were slightly selenium deficient. The synthesized material was also evaluated for the photoelectrochemical (PEC) splitting of water. The PEC study revealed the bifunctional nature of the material, which can be applied for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), by switching the applied potential.

Cesium Lead Halide Perovskite Nanostructures: Tunable Morphology and Halide Composition.

Inorganic halide perovskite (CsPbX3 ) nanostructures have gained considerable interest in recent years owing to their enhanced stability and optoelectronic applications. Recent developments in the synthesis of nanostructures are reviewed. The impact of the precursor and ligand nature, temperature and growth time on the morphology and shape tuning of CsPbX3 nanostructures is described in relation to their optical properties. The presynthetic and postsynthetic anion exchange strategies to retain pre-existing crystal phase and shape are discussed in this minireview.

Effect of cationic disorder on the energy generation and energy storage applications of Ni x Co3-x S4 thiospinel.

Thiospinels show interesting catalytic and energy storage applications, however, the cationic disorder can have major influence on the energy generation and/or energy storage applications. In this study, the effect of stoichiometric variation of metals in a thiospinel i.e. Ni x Co3-x S4, is examined on energy generation and storage properties. Nickel- or cobalt-rich Ni x Co3-x S4 nanosheets were prepared by the hot injection method using single molecular precursors. The nanosheets were characterized by p-XRD, TEM, HR-TEM, EDX and XPS techniques. Nickel-rich and cobalt-rich nanosheets were tested for oxygen and hydrogen evolution reactions and for supercapacitance performance. It was observed that the nickel-rich Ni x Co3-x S4 nanosheets have superior energy storage and energy generation properties.

Trolox ameliorates 3-nitropropionic acid-induced neurotoxicity in rats.

3-nitropropionic acid (3-NPA) is a naturally occurring neurotoxin produced by legumes of the genus Astragalus and Arthrium fungi. Acute exposure to 3-NPA results in striatal astrocytic death and variety of behavior dysfunction in rats. Oxidative stress has been reported to play an important role in 3-NPA-induced neurotoxicity. Trolox is a potent free radical chain breaking antioxidant which has been shown to restore structure and function of the nervous system following oxidative stress. This rapid and efficient antioxidant property of trolox was attributed to its enhanced water solubility as compared with alpha-tocopherol. This investigation was aimed to study the effect of trolox against 3-NPA-induced neurotoxicity in female Wistar rats. The animals received trolox (0, 40 mg, 80 mg and 160 mg/kg, orally) daily for 7 days. 3-NPA (25mg/kg, i.p.) was administered daily 30 min after trolox for the same duration. One additional group of rats served as control (vehicle only). On day 8, the animals were observed for neurobehavioral performance. Immediately after behavioral studies, the animal's brains were dissected out for histological studies. Lesions in the striatal dopaminergic neurons were assessed by immunohistochemical method using tyrosine hydroxylase immunostaining. Administration of 3-NPA alone caused significant depletion of striatal dopamine and glutathione, whereas, the levels of thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) were significantly increased suggesting an elevated level of oxidative stress. Trolox significantly and dose-dependently protected animals against 3-NPA-induced neurobehavioral, neurochemical and structural abnormalities. These results clearly suggest that protective effect of trolox against 3-NPA-induced neurotoxicity is mediated through its free radical scavenging activity.