La Nanoparticles Research Articles

Thermoluminescence and kinetic parameters of irradiated dopant calcium aluminate nanophosphors

CaAl2O4:0.1% La nanoparticles doped with different concentrations of Mg were prepared using the sol–gel method and annealed at 400 °C, 500 °C, and 800 °C, respectively. The prepared nanophosphors show a highly crystalline orthorhombic structure with a crystallite size of about 81.2 nm. The optimum concentration of Mg dopants is about 0.7 mol%. The thermoluminescence (TL) glow curve of 11 Gy of beta-ray irradiated CaAl2O4:0.1% La:0.7% Mg measured at heating rates of 5 K/s has 16 overlapping glow peaks. The TL kinetic parameters for the prepared nanoparticles were evaluated using two different methods and they exhibited good agreement. Moreover, the linearity dose response of dosimetric peaks follows a good linearity up to 220 Gy in nanophosphor. The minimum detectable dose of the prepared nanophosphor was 125.7 mGy. The results of the prepared nanophosphors suggest good candidates for dosimetric applications.Graphical abstract

Enhancing photocatalytic degradation of La-BiVO4 through bidirectional regulation of oxygen vacancy and the Mott-Schottky effect

Selective oxidation of photocatalysts is an important reaction, but catalytic capacity and reaction selectivity are usually contradictory. Herein, ultrafine La nanoparticles were introduced to regulate and control the coordination number and environment of Bi, and a catalyst was synthesized with oxygen defects (La-BiVO4) for Rhodamine degradation. Particularly, La-BiVO4 achieved a better reaction rate and selectivity under visible-light irradiation. The results revealed that the degradation rate of Rhodamine by La-BiVO4 reached 94.9 %. Additionally, the characterization and density functional theoretical calculation demonstrated that the Mott-Schottky effect in La-BiVO4 not only changed the BiVO4 electron density and boosted the visible-light-sensitivity, but also hastened the photogenerated charge migration and reduced the energy barrier. This study not only reveals the important role of optimizing single-atom coordination environment in generating free radicals in photocatalytic reactions, but also provides a reasonable degradation strategy for specific pollutants in the environment.

Lanthanum nanoparticle decorated carbon nanotubes: Facile method of synthesis and studies of their redox stability, cytotoxicity and corrosion inhibition on the magnesium alloy in 3.5 % NaCl environment

Functionalized carbon materials can act as high-temperature coatings and eco-friendly composite materials. We have studied lanthanum-doped carbon nanotube (La-CNT) material redox behavior, cytotoxicity, and corrosion inhibition efficiency. The La-CNT material has been characterized by different techniques to confirm the presence of functional groups. The Fourier transform infrared (FTIR) and Raman studies were performed to investigate the functional groups and carbon defects. Field emission scanning electron microscopy (FESEM) and tunneling electron microscopy (TEM) studies were used to investigate the carbon nanotube microstructure, La nanoparticles were shown to interact with the carbon nanotube surface. X-ray diffraction (XRD) techniques were used to confirm the crystallinity of composite material. Electrochemical methods were used to investigate corrosion inhibition and redox stabilities. After corrosion study on the Mg alloy its microstructure was analyzed to confirm the composite material inhibition efficiency. The composite material showed significant cytotoxicity, and corrosion inhibition efficiency was shown to be 82 % as compared with pristine epoxy-coated Mg alloy.XPS results are suggested that alloy oxide layer formed. The DFT study supported the experimental findings.

Photothermal catalytic hydrolysis of COS with enhanced efficiency over constructed alkali-modified La-Ti catalyst: Adjusting photogenerated electron behavior through metal‐support interactions

The low-temperature conversion of corrosive carbonyl sulfide (COS) in steel by-product gas is essential for the clean utilization of this gas. Herein, La-Ti@K catalysts doped with La nanoparticles were shown to exhibit significant photopromoted thermocatalytic activity and stability under UV light irradiation. At a reaction temperature of 60 °C, the TOF value increased from 4.84 × 10-4 s−1 (TiO2, thermal treatment) to 8.43 × 10-4 s−1 (La-Ti@K, photothermal treatment), and the H2S selectivity exceeded 99%. This was because La doping increased the density of basic sites on TiO2, which promoted the continuous dissociation of H2O in the system and the regeneration of –OH under UV irradiation. Moreover, the photogenerated electrons from TiO2 were transferred to La to maintain the metallic La nanoparticles, as well as to ensure the activation and photothermal hydrolysis of COS. The presence of a suitable electron-metal-support interaction (EMSI) between the electron-rich La nanoparticles and TiO2 might be responsible for these phenomena. In addition, theoretical calculations revealed that light-induced electron transfer was conducive to H2O dissociation and COS activation, while La doping reduced the free energy of the hydrolysis reaction. This work demonstrates the effectiveness of La-Ti@K catalyst in COS photothermal hydrolysis and provides a theoretical basis for further understanding of the photothermal catalytic mechanism.

Evaluation of structural, optical and morphological properties of La doped TiO2 nanoparticles

The optical, structural, electrical, and gas-sensing properties of pure and lanthanum-doped TiO2:La nanoparticles are studied in this research. According to the X-ray diffraction measurements, the synthesized material grew in a tetragonal phase with (101) preferential orientation. The optical features of UV spectra reveals that all samples had high reflectance >80% in the visible area, and the band gap was determined to be between 3.49 and 3.4 eV, with an increase of up to 7.5% of La. The PL spectra reveals the strong UV emission peak that shifted marginally to a higher wavelength as the sample's doping concentration increased. The synthesized TiO2: La's size was assessed using TEM. TiO2:La nanoparticle particles may be seen in TEM pictures, and their typical crystallite size is 7 nm. The PL reveals the presence of oxygen vacancy in the produced TiO2:La sample. Thermal behaviour of the sample reveals an exothermic response with a maximum weight loss rate of 12%/min at around 400 °C, and total decomposition was determined after 50 min at a heating rate of 10 °C/min. The impedance spectroscopy research shows that resistance variations caused by grain boundaries considerably influenced the properties of the gas sensor in parameters that describes the electrochemical system's low-frequency behavior. Although the study for a precise mechanism continues, the change in impedance caused by a particular gas is commonly associated to transport mechanisms such as adsorption and charge transfer.

Atomically Ordered Pt5La Nanoparticles as Electrocatalysts for the Oxygen Reduction Reaction

In this study, atomically ordered intermetallic Pt5La nanoparticles (NPs) were successfully prepared using a relatively simple wet chemical process. X-ray diffraction measurements were carried out to determine the crystal structures of the prepared catalysts. The transmission electron microscopy results revealed that the Pt5La NPs with a size of 3–15 nm were distributed on the carbon surface. The crystal structure of the Pt–La alloy depended on the annealing temperature. A face-centered cubic-type (i.e., a disordered phase) structure was formed at temperatures less than 700 °C, while a CaCu5-type structure (i.e., an ordered phase) could be formed at 800 °C. The prepared Pt5La NPs exhibited oxygen reduction reaction (ORR) specific (1.39 mA cm–2) and mass (0.657 A mg–1) activities approximately 3.7 and 5.1 times higher than those of commercially available Pt NPs on carbon, respectively. Furthermore, the as-prepared NPs showed enhanced ORR durability. The enhanced ORR activity was evaluated through surface analysis using high-angle annular dark-field scanning transmission electron microscopy and X-ray photoelectron spectroscopy. The significantly enhanced ORR activity of the ordered Pt5La NPs was due to their compressive strain and rich atomic steps. The findings of this study will be helpful in the development of electrocatalysts with high electrochemical activity.

Poly‐L‐lysine‐coated α‐lactalbumin nanoparticles: preparation, effect of pH, and stability under in vitro simulated gastrointestinal conditions

AbstractBACKGROUNDThe development of bioactive compound delivery systems using protein‐based nanoparticles as carriers is a rapidly growing field of study. α‐Lactalbumin (α‐La) nanoparticles are adequate for this task because they are nonantigenic, biodegradable, and easily modifiable via the surface physical adsorption of other molecules. Here, the effect of poly‐L‐lysine (PLL) coating of α‐La nanoparticles on the stability against enzymatic degradation in the gastrointestinal tract was investigated.RESULTSα‐La nanoparticles were prepared by desolvation with acetone. It was observed that the pH of the initial protein suspension did not have a significant effect on the size, polydispersity index (PDI), or ζ‐potential of the nanoparticles, so the subsequent experiments were performed at pH 9, where 151.2 nm nanoparticles with a PDI of 0.072 and a ζ‐potential of −29.7 mV were obtained. The nanoparticles coating was performed with two MW‐range PLL at three concentrations. Coating efficiency increased as the polymer concentration increased and this was independent of the PLL MW. The best coating efficiency (90–95%) was obtained in the case of the 1 mg mL−1 PLL coating. Most PLL‐coated nanoparticles showed a good stability to the conditions of in vitro simulated gastrointestinal digestion compared with the uncoated nanoparticles.CONCLUSIONIt can be concluded that the acetone desolvation method at pH 9 is adequate to obtain α‐La nanoparticles with good characteristics. The process of PLL coating of nanoparticles showed an increase in efficiency with the increase in concentration of the polymer. The resulting coated nanoparticles had enhanced resistance to simulated gastrointestinal conditions. © 2021 Society of Chemical Industry (SCI).

Rendering Redox Reactions of Cathodes in Li-Ion Capacitors Enabled by Lanthanides.

Capacitors allow extremely fast charge and discharge operations, which is a challenge faced by recent metal-ion batteries despite having highly improved energy densities. Thus, combined type electric energy storage devices that can integrate high energy density and high power density with high potentials, can overcome the shortcomings of the current metal-ion batteries and capacitors. However, the limited capacities of cathode materials owing to the barren redox reactions are regarded as an obstacle for the development of future high-performance hybrid metal-ion capacitors. In this study, we demonstrate the redox-reaction-rendering effect of the much overlooked lanthanide elements when used as the cathode of lithium-ion capacitors using the mesoporous carbon (MC) as a matrix material. Consequently, these lanthanide elements can effectively enrich the redox reaction, thus improving the capacity of the matrix materials by more than two times. Typically, the Gd-elemental decoration of MC surprisingly enhances the capacity by almost two times as compared with the underacted MC. Furthermore, the La nanoparticles (NPs) decoration depicts the same behavior. Evident redox peaks were formed on the original rectangular cyclic voltammetry (CV) curves. This study provides the first example of embedding lanthanide elements on matrix materials to enrich the desired redox reactions for improving the electrochemical performances.

Comparative study of CuO, CuO@Ag and CuO@Ag:La nanoparticles for their photosensing properties

In this work, the synthesis of CuO, CuO@Ag core-shell, and CuO@Ag:La nanoparticles was done by sol gel technique. The prepared nanoparticles were further characterized for their structural, morphological and optical properties. The color coordinates of PL spectra showed that CuO@Ag:La nanoparticles has much better application potential in white light emission than CuO and CuO@Ag core-shell nanoparticles. Further, the synthesized CuO@Ag:La nanoparticles were implemented for fabrication of Glass/ITO/synthesized nanoparticles/Al thin film device. The fabricated device was tested for bias voltage. Results verified that the behavior of the fabricated device is similar to photoresistor and shows better sensitivity towards light. Electrical characterization confirmed that the resistance of CuO@Ag:La nanoparticles based device decreases exponentially with increase in the intensity of light while the photoresponse increases. It is therefore revealed that the CuO@Ag:La nanoparticles are an efficient material for fabrication of photosensitive devices.

Exploring Microemulsion-Prepared Lanthanum Catalysts for Natural Gas Valorisation

Microemulsions were used to develop a catalyst with high selectivity towards ethylene and ethane while maintaining considerable methane (CH4) conversion. The use of this technique to produce lanthanum nanoparticles was studied under different conditions. Temperature was shown to have the most significant effect on the final material properties providing a minimum crystallite size at 25°C. The morphology observed for all the samples was flake or needle like materials containing nanocrystallites. To obtain the catalytically active materials a thermal treatment was needed and this was studied using in situ X-ray diffraction (XRD). This analysis demonstrated that the materials exhibited significant changes in phase and crystallite size when submitted to thermal treatment and these were shown to be difficult to control, meaning that the microemulsion synthesis method is a challenging route to produce La nanoparticles in a reproducible manner. The materials were tested for oxidative coupling of methane (OCM) and no correlation could be observed between the ‘as synthesised’ crystallite size and activity. However, the presence of La carbonates in the materials produced was deemed to be crucial to ensure an adequate OCM activity.

Synthesis of carbon nanofibers over lanthanum supported on radially aligned nanorutile: A parametric study

Radially aligned nano-rutile (RANR) was synthesized using the hydrothermal technique. This material was used as catalyst support for Lanthanum (La) nanoparticles which were loaded onto the RANR support by a deposition-precipitation method using urea (DPU) to form La/RANR catalysts. It was observed from TEM images that the width of the nanorods making up the RANR support is ca. 9 nm and the actual RANR is heterogeneously sized, with spherical microstructures that have radii ranging between 1.2 and 1.6 μm. The La nanoparticles were loaded onto RANR at weight percentages ranging from 0.5 to 10 wt%. The as-synthesized La/RANR catalyst was used to catalyze the synthesis of carbon nanofibers (CNFs) by chemical vapor deposition (CVD), using acetylene as a carbon source and hydrogen as a reducing gas. A parametric study was conducted to investigate how gas flow rate, synthesis temperature, reaction time, and La loading on La/RANR affected the growth of CNFs by monitoring the morphology, graphicity and thermal properties of the products. It was observed that 5 wt% La/RANR yielded CNFs with the lowest width and highest graphicity and thermal stability, particularly for the ones synthesized at 700 °C. These CNFs were used as an adsorbent and were observed to have adsorbed over 90% of methyl red within 5 min.

Biogenic synthesis, characterization and biological activity of lanthanum nanoparticles

Abstract Need for metal nanoparticles in the various fields are increasing in recent year because of the excellence in their activity. In this study, biogenic lanthanum (La) nanoparticles were synthesized through ecofriendly green chemistry methodology. Mutingia calabura leaf extract was used for the synthesis of La nanoparticles. The synthesized La nanoparticles were characterized using FTIR, SEM and EDAX. Further, the nanoparticles were analysed for antibacterial activity, bacterial toxicity, antioxidant activity, blood compatibility and dye degradation efficiency. Well diffusion technique was used to study the antibacterial activity and antioxidant activity was evaluated using DPPH assay. Photocatalytic dye degradation study was carried out with Coomasie brilliant blue dye. Peaks obtained in the FTIR analysis of the plant sample confirmed the presence of the carbonyl, hydroxyl and amine group which was responsible in bioreduction for La nanoparticles synthesis. Size of La nanoparticles was less than that of 100 nm as observed in SEM. EDAX analysis confirmed the presence of lanthanum in the synthesized La nanoparticles. DPPH assay results showed that La nanoparticles providing 70.06% inhibition percentage. Mutingia calabura leaf extract based La Nanoparticles showed good bactericidal activity against Klebsiella pneumonia, Proteus mirabilis, Staphylococcus aureus and E. coli Sps. Blood compatibility study showed involvement of La nanoparticles in blood coagulation mechanism and thrombolytic activity. Furthermore, La nanoparticles were effective in Coomassie brilliant blue dye degradation beneath the sunlight. Results obtained in the above study show that Mutingia calabura leaf extract synthesized La nanoparticles can be used for both biological and environmental application.

Photocatalytic degradation and ferromagnetism in mesoporous La doped ZnS nanoparticles

The influence of Lanthanum (La) doping on the crystalline phase, thermal, optical, photocatalytic degradation and ferromagnetic properties of mesoporous ZnS:La nanoparticles is investigated. BET surface studies confirm the presence of mesoporous in the ZnS and ZnS:La nanoparticles. Photocatalytic activity of 5 wt% La doped ZnS is evaluated by the degradation of Turquoise Blue H5G in aqueous solution under sunlight. The photomineralization and photostability are validated by TOC and ICP-OES analyses. Photoconductivity measurements confirm the production of photocharge carrier. The long range ferromagnetism in La doped ZnS nanostructures due to defects is formed by vacancies and lattice deformation. Morphology and the size of the nanoparticles are probed by field emission scanning microscope. TEM images confirm the hexagonal structure of the doped sample. The cubic structure of undoped ZnS and hexagonal structure of mesoporous La doped sample is confirmed by Raman modes. The thermal analysis of La doped nanoparticles is analyzed by using thermo gravimetric and differential scanning calorimetry method.

Facile synthetic method of catalyst-loaded ZnO nanofibers composite sensor arrays using bio-inspired protein cages for pattern recognition of exhaled breath

Functionalization of catalytic nanoparticles (NPs) on semiconductor metal oxide (SMO) sensing layer is an indispensable process to obtain improved sensitivity and selectivity for high performance chemical sensors. It is a critical challenge to achieve homogeneous distribution of nanoscale catalysts on SMO in consideration that gas sensing characteristics of SMO-based sensing layer are significantly influenced by the size and distribution of catalysts. Here, we propose a highly effective functionalization method to achieve well-distributed catalytic NPs onto one dimensional (1D) SMO nanofibers (NFs) using protein cage templates: apoferrtin. By simply replacing precursor in the apoferritin assisted method, not only precious catalyst such as Pt but also non-precious catalysts such as La and Cu were successfully synthesized in nanoscale (i.e., 3–5nm). Furthermore, the apoferritin-encapsulated catalysts exhibited high dispersion property due to repulsive force between protein shells. For this reason, catalytic NPs were homogeneously decorated on ZnO NFs after electrospinning followed by calcination. Catalytic Pt NPs and Cu NPs functionalized ZnO NFs exhibited approximately 6.38-fold (Rair/Rgas=13.07) and 2.95-fold (Rair/Rgas=6.04) improved acetone response compared with the response (Rair/Rgas=2.05) of pristine ZnO NFs. In the case of La NPs functionalized ZnO NFs, 9.31-fold improved nitrogen monoxide response (Rair/Rgas=10.06) was achieved compared with the response of pristine ZnO NFs. The four catalyst-ZnO composite NFs successfully distinguished simulated breath components such as acetone, toluene, nitrogen monoxide, carbon monoxide, and ammonia with well-classified patterns by principal component analysis (PCA). This work demonstrated a robustness of synthetic and functionalization method using bio-inspired protein templates combined with electrospinning technique and a promising potential of using non-precious catalysts to establish diverse sensing material libraries that can be applicable to breath pattern recognition for diagnosis of diseases.

Influence of lanthanum doping via hydrothermal and reflux methods on the SnO2–TiO2 nanoparticles prepared by sol–gel method and their catalytic properties

In the present work, tin oxide–titanium oxide (SnO2TiO2) nanoparticles were synthesized via sol–gel method and doping of lanthanum (La) on tin oxide–titanium oxide (La/SnO2TiO2) nanoparticles was carried out using hydrothermal and reflux methods. Effect of different preparation methods on the size and catalytic properties of nanoparticles was investigated. The La/SnO2TiO2 nanoparticles were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, powder X-ray diffraction and solid phase spectroscopy. The UV–Vis spectroscopy was used to investigate its catalytic properties for methylene blue degradation. It was found that La/SnO2–TiO2 nanoparticles prepared by hydrothermal method have small size and maximum degradation capacity. The red shift in La nanoparticles was observed with band gap of 4.25 eV as compared to bulk material.

Differential pulmonary effects of CoO and La2O3 metal oxide nanoparticle responses during aerosolized inhalation in mice.

BackgroundAlthough classified as metal oxides, cobalt monoxide (CoO) and lanthanum oxide (La2O3) nanoparticles, as representative transition and rare earth oxides, exhibit distinct material properties that may result in different hazardous potential in the lung. The current study was undertaken to compare the pulmonary effects of aerosolized whole body inhalation of these nanoparticles in mice.ResultsMice were exposed to filtered air (control) and 10 or 30 mg/m3 of each particle type for 4 days and then examined at 1 h, 1, 7 and 56 days post-exposure. The whole lung burden 1 h after the 4 day inhalation of CoO nanoparticles was 25 % of that for La2O3 nanoparticles. At 56 days post exposure, < 1 % of CoO nanoparticles remained in the lungs; however, 22–50 % of the La2O3 nanoparticles lung burden 1 h post exposure was retained at 56 days post exposure for low and high exposures. Significant accumulation of La2O3 nanoparticles in the tracheobronchial lymph nodes was noted at 56 days post exposure. When exposed to phagolysosomal simulated fluid, La nanoparticles formed urchin-shaped LaPO4 structures, suggesting that retention of this rare earth oxide nanoparticle may be due to complexation of cellular phosphates within lysosomes. CoO nanoparticles caused greater lactate dehydrogenase release in the bronchoalveolar fluid (BALF) compared to La2O3 nanoparticles at 1 day post exposure, while BAL cell differentials indicate that La2O3 nanoparticles generated more inflammatory cell infiltration at all doses and exposure points. Histopathological analysis showed acute inflammatory changes at 1 day after inhalation of either CoO or La2O3 nanoparticles. Only the 30 mg/m3 La2O3 nanoparticles exposure caused chronic inflammatory changes and minimal fibrosis at day 56 post exposure. This is in agreement with activation of the NRLP3 inflammasome after in vitro exposure of differentiated THP-1 macrophages to La2O3 but not after CoO nanoparticles exposure.ConclusionTaken together, the inhalation studies confirmed the trend of our previous sub-acute aspiration study, which reported that CoO nanoparticles induced more acute pulmonary toxicity, while La2O3 nanoparticles caused chronic inflammatory changes and minimal fibrosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12989-016-0155-3) contains supplementary material, which is available to authorized users.

Enhancement of local microstructural distortions, boundary weak-interactions and crucial defeats performed via Bi+3/La+3 partial substitution in the Bi-2212 matrix

This exhaustive study examines not only the decrement in characteristic two-stage (pairing and coherence) transitions but also the characteristic variation of the mechanical performance with the partial substitution level of homovalent La nanoparticles on Bi sites in the Bi-2212 crystal structure with the aid of the detailed dc resistivity (ρ-T), bulk density, Vickers microhardness (Hv) experimental findings and evaluated theoretical calculations. The experimental results obtained show that both the electrical and superconducting properties being responsible for the potential technological and industrial applications degrade consistently with the increment of the La inclusions in the Bi-2212 superconducting matrix. In fact, the crucial characteristics disappear completely after the critical dopant value of x = 0.20 as a result of the full deformation between the Bi-2212 planes and grain boundaries. In other words, the excess La impurities lead to the disorder and hole localization (filling) problem in the system due to the normal-state electrical resistance transition from the truly-metallic state to the disordered metallic state, and the electrical and superconducting properties demolish totally due to the metal to insulator transition (MIT). In this paper, we focus only on the (Bi,La)-2212 materials exhibiting superconducting behavior to reveal granular superconducting nature of Bi1.6-xLaxPb0.5Sr2.0Ca1.1Cu2.1Oy. As for the theoretical values deduced from the resistivity curves, temperature derivatives of the sample resistivities (dρ/dT) confirm characteristic two-stage transitions in all the samples prepared and both the pairing (bulk genuine) and coherence transitions tend to suppress with the increase of the La inclusions inserted in the Bi-2212 superconducting core as a consequence of the presence of the increased structural inhomogeneities (distribution of oxygen) and grain boundaries. Moreover, Percolation model confirms that the decrease in the coherence transitions with the dopant level is explained with the enhancement of Josephson coupled energy and the degradation of coupling probability. The existence of the relationship between microstructure and strength of interaction between the grains is also confirmed by the bulk density and porosity surveys. As for the load dependent microhardness parameters deduced from Vickers measurements, the pure sample exhibits the Indentation Size Effect (ISE) behavior whereas the La nanoparticles inserted in the Bi-2212 superconducting system make the materials present Reverse Indentation Size Effect (RISE) feature. This is attributed to the fact that the local structural distortions and boundary weak-interactions between the superconducting grains enhance dramatically with the La doping. In other words, plastic (irreversible) deformation becomes a much more dominant character in the materials as a result of the loss of the elastic recovery. At the same time, we analyze the microhardness experimental findings with the aid of the available models such as Meyer's law, proportional sample resistance (PSR), modified PRS (MPSR), Elastic–Plastic Deformation (EPD), Hays–Kendall (HK) and Indentation-Induced Cracking (IIC) approach for the first time. The results determined show that HK approach is found to be the best descriptor to examine the mechanical performance of the pure sample, showing ISE nature while the IIC model is observed to be the most successful model in understanding the mechanical properties of the Bi-site La substituted Bi-2212 superconducting compounds, obeying RISE nature.

Synthesis, structural, optical and Raman studies of pure and lanthanum doped ZnSe nanoparticles

In this work, a simple, effective and reproducible chemical synthetic route for the production of high-quality, pure ZnSe nanoparticles (NPs), and lanthanum-doped ZnSe (ZnSe:La) NPs is presented. The wide bandgap, luminescent pure ZnSe and ZnSe:La NPs has been synthesized at a low temperature (100°C) in a single template-free step. The size and optical bandgap of the NPs was analyzed from powder X-ray diffraction (XRD), UV–visible (UV–vis) spectroscopy, transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). A broad photoluminescence (PL) emission across the visible spectrum has been demonstrated by a systematic blue-shift in emission due to the formation of small nanoparticles. Here, contribution to emission intensity from surface states of NPs increases with La doping. TEM data revealed that the average size of ZnSe and ZnSe:La NPs is 14 and 8nm, respectively. On the other hand, band gap energy Eg of ZnSe and ZnSe:La NPs were found to be 3.59eV and 3.65eV, respectively. Results showed that hydrazine hydrate played multiple roles in the formation of ZnSe and ZnSe:La NPs. A possible reaction mechanism for the growth of NPs is also discussed.