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A novel, highly efficient, reusable heterostructured nanocomposite photocatalyst and antibacterial agent was prepared successfully by combustion method. The structural and crystallinity of synthesized nanocomposites were well characterized by Powder X-ray diffraction (P-XRD) which confirms the purity and phase formation by diffraction peaks related to CuO, Cu 2 O, metallic Cu of nanocomposites. The proximity of Fe directly affects the crystallinity of Cu 2 O/CuO/Cu (CCC) and changes the morphology with observable voids and pores in Scanning Electron Microscopy (SEM). In addition, X-Ray Photoelectron Spectroscopy (XPS) results indicated the existence of doped Fe as Fe3+ and Fe2+ ions within the CCC nanocomposite lattice. The UV–Visible absorption spectroscopy illustrates a decrease in the band gap energy for the nanocomposites CCC (1.9 eV) and CCC-Fe (1.7 eV) which proves the dopant Fe hinders the recombination of e-–h+ pairs by trapping electrons and holes, causing an enhancement in this degradation process. This depicts the ability of Fe-doped CCC as a better photocatalyst under Sunlight irradiation than CCC. This was confirmed by the obtained results of photocatalytic performance of Fe doped CCC (5 mol%) on Methylene Blue (MB) and Rhodamine B (RhB) dyes. The degradation was found to be 93% and 81% respectively under irradiation of Sunlight for 60 min, whereas for CCC, the obtained result was 65% (MB) and 60% (RhB) under same condition. The CCC-Fe nanocomposite also shows considerable specific capacitance with 84.55 F/g from cyclic voltamogram and 83 F/g from charge discharge studies with durability of 2000 cycles ascertains the supercapacitor nature. Further, the remarkable antibacterial activities of Fe-doped CCC nanocomposites against E. coli and S. Aureus (100 μg/mL) were discussed. The excellent results of Fe-doped CCC nanocomposite showed a prominent multifunctionality in suppressing organic pollutants and bacteria in the environment. [ABSTRACT FROM AUTHOR]

This research deals with the facile combustion synthesis of manganese ferrite (MFO) nanoparticle with different cerium concentration and their potential application as an efficient photocatalyst and chemical sensor. The concentration of introduced cerium affects the size, structure, compositional, morphological, optical, photoluminescence and magnetic properties of the ferrite nanoparticle. The X-ray diffraction pattern affirmed the arrangement of cubic spinel structure with the formation of secondary phase CeO 2 as the cerium concentration exceed 3 mol%. SEM micrographs revealed irregular morphology with more number of pores and voids. HRTEM along with SAED pattern revealed the crystalline cubic nature. The optical band gap deduced from UV–Vis-DRS spectra was observed to be in the range 2.3–2.8 eV. PL studies indicated a significant minimization in combination of electrons & holes in MnFe 2 O 4 on addition of Ce dopant. VSM investigation demonstrated the soft magnetic nature of the prepared sample with moderate magnetization value. An excellent photocatalytic performance of Cerium doped MFO (3 mol%) towards MB and AR dye degradation was found to be 1.5 and 1.67 times more compared to host matrix under Sunlight irradiation that correlated to reduced band gap, Ce dopant and efficient separation of charge carriers. Cerium doped MFO (3 mol%) have high specific capacitance value of 471.7 and 1546.8 Fg-1 for NaNO 3 and HCl electrolytes respectively, indicating the pseudo capacitance nature due to which it can be used as a supercapacitor. The synthesized nanoparticles can sense d -Glucose and Paracetamol even at a lower concentration varying from 1 to 10 mM. The synthesized Ce-doped MnFe 2 O 4 nanomaterials have great potential to be used in the future production of promising active photocatalysts and sensitive chemical sensors for the identification and degradation of toxic industrial dyes for improved safety in the fields of environment and health care. [ABSTRACT FROM AUTHOR]

Here, we investigate the effect of temperature on solution combustion synthesized MnFe 2 O 4 nanoparticles (NPs) as supercapacitor electrode material that would affect the structural, optical, electrochemical, magnetic and sensing properties. The variation in temperature influences the structure and morphology of synthesized NPs which in turn produces defect states in NPs. Powder X-ray diffraction studies confirms the presence of cubic spinel structure with increase in crystallinity and crystallite size with increase in temperature. Scanning electron microscopy analysis indicates the morphology change in NPs from spherical to network like interlinking to the formation of polyhedron structure at higher temperature. Photoluminescence, energy dispersive X-ray analysis, X-ray photoelectron scpectroscopy and UV-visible diffused reflectance spectroscopy studies emphasize the increase in surface oxygen vacancies concentration with narrowing of band gap from 2.9 to 2.5 eV. Electrochemical studies designate the excellent performance and desirable cyclic stability of synthesized NPs. In particular, the specific capacitance of synthesized NP increases with increase in temperature, reaching highest specific capacitance from CV was 297.7 F/g for 0.1 M HCl and 158.85 F/g for 0.1 M NaNO 3 electrolytes for NP synthesized at 500 °C. The synthesized NPs show excellent stability with high capacity retention in both the electrolytes. The graphite modified electrode can also sense Paracetamol and d -Glucose at a very low concentration of 1–5 mM. Meanwhile, it acts as a very good photocatalyst to decolourize Methylene Blue and Alizarin Red S dye under Sunlight illumination due to the increase in concentration of surface oxygen vacancies with narrow band gap. Finally, the synthesized MnFe 2 O 4 NP can be used as a potential supercapacitor electrode with excellent stability and recyclability, to sense the analyte even at very low concentration and also act as a photocatalyst with high recyclability with the help of magnetic nature towards environmental cleaning. [ABSTRACT FROM AUTHOR]

Photocatalytic activity of (CuO-Cu 2 O)Cu/ZnO hetero-junction nanocomposites along with their luminescent, biological applications in the progress of anticancer and antibacterial agents is investigated. The Cu and Zn bi-components modified (CuO-Cu 2 O)Cu/ZnO nanocomposites were synthesized via facile combustion route in the presence of controlled fuel to oxidizer ratio and were characterized by X-Ray Diffraction (XRD) patterns, Transmission electron microscopy (TEM), High resolution Transmission electron microscopy (HRTEM), Scanning Electron Microscopy (SEM), X-ray photoelectron Spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and energy dispersive X-ray (EDX) analysis. The PL and UV–Visible diffused reflectance spectral (UV–Vis-DRS) techniques were used to measure the optical sensitivity and tuning of band gap in the samples. The excellent photocatalytic degradation of Methylene Blue and industrial waste water under Sunlight irradiation depends on the mass ratios of Cu/Zn. The findings show that the addition of a certain proportion of CuO, Cu 2 O, ZnO, and Cu can promote efficiency in Sunlight harvesting and separation of charge carriers. Process parameters namely catalyst quantity, dye concentration and a proposal for the mechanism of degradation pathway, experiments for trapping and enhancer are investigated. The study of photoluminescence, CIE and CCT calculations suggests that the present nanocomposite may find applications as phosphor material in warm white LEDs. The second segment of this study deals with the investigation of antibacterial performance of composites upon Gram-negative and Gram-positive bacteria. The results indicate that nanocomposites can be used in antibacterial control systems and as an important growth inhibitor in various microorganisms. The cytotoxic effect of the (CuO-Cu 2 O)Cu/ZnO (CCCZ11) nanocomposite was determined by colorimetric and flow cytometric cell cycle analysis. Our experimental results show that the nanocomposite can induce apoptosis and suppress the proliferation of HeLa cells. The applications of nanocomposites based on Cu, an abundant and inexpensive metal has created much interest in various multifunctional applications. [ABSTRACT FROM AUTHOR]

This work majorly aims to synthesize and also investigate the structural, optical, magnetic and optical features of ZrO 2 /ZnFe 2 O 4 nanocomposite. Here, different ratios of novel hetero-junction ZrO 2 /ZnFe 2 O 4 were synthesized by simple and fast solution combustion route. The X-ray diffraction results showed the formation of ZrO 2 and ZnFe 2 O 4 nanoparticles and ZrO 2 /ZnFe 2 O 4 nanocomposites without any impurity. The formation of hetero-junction effectively inhibits the photo-generated charge carrier recombination. The degradation of Indigo Carmine dye by ZrO 2 /ZnFe 2 O 4 photocatalyst was achieved through synergistic effects with 98% degradation and removal of 77% COD from the industrial dye waste water under Sunlight irradiation. Mixing of ferrites with zirconia greatly improves the photocatalytic activity that has been clearly proposed with the help of mechanism. ZZFO 12 NC exhibits better photocatalytic activity due to the combined facets of photo and Fenton activity. The exposure and enhancement of fingerprints in various surfaces are achieved by a modest, extremely sensitive and eco-friendly method. ZZFO12 NC offer great potential as an active photocatalyst for degradation of 54% of organic pollutant present in industrial waste water under natural Sunlight. [ABSTRACT FROM AUTHOR]

In recent years, key study was designing nanomaterials (NMs) with tunable properties in order to obtain high functional materials. For this purpose, an attempt with great effort has been put forward to synthesize ZrO 2 :Eu:Li (1–11 mol%) NM with varying concentration of Li+ ion that can have a control over phase, size, morphology, crystallinity, band gap and surface chemistry. More importantly, addition of Li as codopant influences the phase and crystallinity change with the change in concentration. However important challenges faced by this work was to understand the phase change, crystallinity, structural change and photocatalytic activity which has to be still explored. The synthesized NMs possess mixed phase and cubic phase with change in concentration of codopant which may be attributed to presence of defect states, micro strain, distortion of lattice. The energy band gap was found to decrease for 7 mol% NM attributed to the change in the phase. Porous morphology with variation in pore length was observed. Enhanced luminescence intensity with intense orange red emissions consistent to 5D 0 →7F j (j = 0 to 4) intra configurational f-f transitions was observed for ZrO 2 :Eu:Li+(1–11 mol%) nanophosphor excited at 394 nm. The visualization of latent fingerprints using ZrO 2 : Eu: Li+ 7mol% nanophosphor on several surfaces, the powder dusting technique was adopted. The enhanced fingerprint under UV light provides well resolved ridge patterns for the identification of individual latent finger prints using ZrO 2 :Eu:Li (7 mol%) with clear resolution. Lower charge transfer resistance with enhanced photocatalytic activity for decolourization of Rhodamine B with high pore length to allow multiple reflections under UV light irradiation for 7 mol% NM with reduced band gap and optimum luminescence intensity was observed. Hence, the synthesized ZrO 2 :Eu:Li (7 mol%) can be employed in forensic science towards latent fingerprint development, as a photocatalyst for environmental remediation and as luminescent material in display applications. [ABSTRACT FROM AUTHOR]

The goal of this research is to prepare novel, inexpensive, environment friendly and efficient crystalline CuO samples by green mediated combustion and co-precipitation routes towards environmental remediation and biomedical applications. The influence of preparation routes and Aloe barbadensis miller (Aloe vera) gel on the morphology, size, crystallinity, band gap, defects, photocatalytic, antibacterial, haemolytic and anticancer behaviour of CuO samples were explored. The PXRD, XPS, SEM, TEM, HRTEM and FT-IR were performed to confirm the formation of CuO samples. FTIR studies showed all possible bands of Aloe barbadensis miller gel. FTIR displaying the occurrence of new peaks and peak shifts in the CuO synthesized by green mediated combustion route compared to co-precipitation route is an evidence of the effective interactions between CuO and Aloe vera gel. The PL and UV–Vis-DRS techniques measured the optical sensitivity and tuning of band gap of the CuO samples. The crystallinity and surface properties dependent photocatalytic activities for decolourization of MB and RhB under both UV and Sunlight irradiation were investigated. The results indicated that green mediated synthesized CuO sample displayed high photocatalytic activity compared with co-precipitation route synthesized CuO sample, which mainly resulted from the low crystallinity and crystallite size (6 nm), narrow band gap (1.73 eV) and lower recombination of charge carriers. These synthesized CuO samples also demonstrate excellent antibacterial activity against the bacteria Gram-positive (S. aureus) and Gram-negative (E. coli). The present study probes into the cytotoxicity of CuO samples employing root cells of Allium cepa. In addition, we report the haemolytic activity on goat and human blood along with the implementation of green synthesized CuO sample using an Aloe barbadensis miller extract for the evaluation of anticancer activity in human cervical cancer (HeLa) cells with IC50 value of 310.1 μg/ml. Our studies focus on developing biosynthesized nanomaterials for environmental remediation and biomedical applications. [ABSTRACT FROM AUTHOR]

Novel green reduced graphene oxide with ZnFe 2 O 4 for waste water treatment, display applications as well as a labelling agent to enhance latent fingerprinting. • Green-route for effective reduction of GO to RGO using Emblica officinalis fruit extract. • Eco-friendly route to synthesize multifunctional ZnFe 2 O 4 -RGO nanocomposite. • Nanocomposite catalysts exhibited excellent Sunlight photocatalytic performance. • Nanocomposite can be utilized as a white component in WLED's. • First time nanocomposite photocatalysts employed for latent fingerprint detection. The present study reveals a simple and efficient method for the green reduction of graphene oxide (GO) employing Emblica officinalis fruit extract as a reducing agent. Here, a green sol–gel method has been reported for the preparation of ZnFe 2 O 4 and ZnFe 2 O 4 -reduced graphene oxide (RGO) nanocomposite (NCO) using Aloe Vera extract as a capping agent. PXRD, FT-IR, SEM, TEM and HRTEM confirmed the analytical aspects of synthesized samples. The band gaps of prepared samples were estimated by UV–Vis analysis. PL quenching appears due to the interaction between the surface of the ZnFe 2 O 4 and RGO sheets. The photoluminescence analysis indicates that the present NCO is an effective white component in display applications. The NCO was found to be an alternate to traditional luminescent powder for a safe detection and qualitative improvement of latent fingerprints deposited onto different surfaces. Further, excellent photocatalytic properties of NCO when compared to that of the commercial P25 for various other dye degradation under Sunlight can be attributed to its specific electrical properties and well connected arrangement derived from the structural support of ZnFe 2 O 4 and RGO. This results in significant electron-acceptor/transport of RGO material that are able to decrease the photo-generated electron–hole recombination thus enhancing the photocatalytic performance. [ABSTRACT FROM AUTHOR]

A facile solution combustion synthesis has been adopted to synthesize ZrO 2 /CuO nanocomposite oxides (NCO’s) by utilizing Oxalyl dihydrazide (ODH) as fuel. The X-ray diffraction patterns and TEM analysis reveals the presence of cubic ZrO 2 and CuO in ZrO 2 /CuO NCO’s. The NCO’s synthesized by simple, fast, highly sensitive and low-cost method is found to be an alternate to traditional luminescent powders for the detection and enhancement of finger marks in a broad range of surfaces. The photoluminescence analysis indicates that the present NCO is an effective blue component in display applications. The synthesized ZrO 2 /CuO (2:1) composite exhibited excellent photocatalytic activity towards the degradation of various dyes under Sunlight. In particular, Indigo carmine dye was chosen to explore the photocatalytic performance of prepared NCO’s under Sunlight illumination. It was found that ZrO 2 :CuO (2:1) NCO showed enhanced photocatalytic activity of 97% which was found to be 3.3 times 2.4 times and 1.5 times higher than that of pure ZrO 2 , CuO and commercial P25. This can be mainly attributed to the balance between the parameters, band gap, nature of morphology, crystallite size, defects and surface area which causes a slow electron-hole pair recombination rate with fast electron transfer ability. It opens new window to use this simple method to synthesize multifunctional character ZrO 2 -based composite materials in the area of photocatalysis particularly waste water treatment, display applications as well as a labeling agent to enhance latent fingerprints. [ABSTRACT FROM AUTHOR]

A series of Sm doped ZrO 2 nanomaterials (NMs) were synthesized at relatively low temperature by bio-template method using Leucas aspera (LA) plant extract as a fuel. Rietveld refinement results verified that the compounds were crystallized in cubic structure with space group Fm -3 m (225). The PL emission, CIE and CCT analysis confirm that, the present photocatalyst can serve as an excellent candidate for cool LEDs. The registered trend (Ω 2 < Ω 4 ) calculated using the Judd–Ofelt theory reveals the ionic character of the Sm O bonds as well as a relatively high symmetry environment around the rare earth ion (RE) site in ZrO 2 . ZrO 2 :Sm 3+ (11 mol%) photocatalyst has a long lifetime (s) and exhibits excellent Sunlight driven photocatalytic activity for the degradation of acid green dye. This could be attributed to surface defects, special electronic structure, decreased band gap, multichannel transitions, long life time and efficient electron−hole separation. [ABSTRACT FROM AUTHOR]

The present investigation explores various morphologies and phases of Mg doped ZrO 2 nanoparticles synthesized by green assisted route. The effect of Mg doping and Aloe Vera gel concentration on phase formation, morphology and optical properties of the nanoparticles were investigated. The photocatalytic performances of the photocatalysts were evaluated for the degradation of Rhodamine B under UV light. 2 mol% Mg doped ZrO 2 displayed excellent photocatalytic activity with the degradation rate of 93%. The enhanced activity is attributed to UV light response, suitable monoclinic to tetragonal ratio as well as oxygen vacancies which greatly enhances the charge carrier separation. Further, the PL studies demonstrated that the present photocatalysts were highly potential for the fabrication of blue component of white light emitting diodes. The present work directs road map in designing of new phyto synthesized photocatalysts with superior activity for environmental clean-up and nanophosphors for display devices. [ABSTRACT FROM AUTHOR]

Cubic ZrO 2 : Fe 3+ (0.5–4 mol%) nanoparticles (NPs) were synthesized via bio-inspired, inexpensive and simple route using Phyllanthus acidus as fuel. PXRD, SEM, TEM, FTIR, UV absorption and PL studies were performed to ascertain the formation of NPs. Rietveld analysis confirmed the formation of cubic structure. The influence of Fe 3+ on the structure, morphology, UV absorption, PL emission and photocatalytic activity of NPs were investigated. The CIE chromaticity coordinates (0.36, 0.41) show that NPs could be a promising candidate for white LEDs. The influence of Fe 3+ on ZrO 2 matrix for photocatalytic degradation of AO7 was evaluated under UVA and Sunlight irradiation. The enhanced photocatalytic activity of spherical shaped ZrO 2 : Fe 3+ (2 mol%) under UVA light was attributed to dopant concentration, crystallite size, narrow band gap, textural properties and capability for reducing the electron–hole pair recombination. The trend of inhibitory effect in the presence of different radical scavengers were followed the order SO 4 2− > Cl − > C 2 H 5 OH > HCO 3 − > CO 3 2− . The recycling catalytic ability of the ZrO 2 : Fe 3+ (2 mol%) was also evaluated with a negligible decrease in the degradation efficiency even after the sixth successive run. [ABSTRACT FROM AUTHOR]

Here, a green route has been reported to convert Graphene Oxide (GO) to reduced graphene oxide (RGO) using clove extract. A modest and eco-accommodating sol-gel strategy has been employed to prepare MgFe 2 O 4 nanoparticles, MgFe 2 O 4 –RGO nanocomposite samples. The samples were analyzed by Powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible Spectroscopy, Scanning Electron Microcopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and Electrochemical Impedance Spectroscopy (EIS). PXRD result revealed that the prepared samples were cubic spinel in nature. SEM results uncovered flake like surface morphology of the prepared nanomaterial. Better PL emission signature was observed when excited at 329 nm. PL studies demonstrated that the present samples were potential for the fabrication of white component of white light emitting diodes (WLEDs). Further, MgFe 2 O 4 –RGO nanocomposite showed enhanced photocatalytic movement (PCM) and photostability under Sunlight in the decomposition of Malachite Green (MG) compared to MgFe 2 O 4 . This can be attributed to the interaction of MgFe 2 O 4 surface with RGO sheets which results in PL quenching, demonstrates that the recombination of photo-induced electrons and holes in MgFe 2 O 4 –RGO nanocomposite is more effectively inhibited. A possible mechanism for the enhanced properties of MgFe 2 O 4 –RGO nanocomposite was discussed. Moreover, MgFe 2 O 4 –RGO photocatalyst also showed easy magnetic separation with high reusability. These results unveil that the synthesized sample can be used in display applications and also as a potential photocatalyst. [ABSTRACT FROM AUTHOR]

We have reported Caralluma fimbriata extract induced simple single step green synthesis of pure and Gd loaded ZnO nanostructures towards the improvement of photocatalytic performance under both UV and Sunlight irradiation. Band gap of 2.97 eV and 95 Ω of charge transfer resistance displayed highest decolorization effectiveness of 90 and 98% underneath UV and Sunlight irradiation respectively for Gd loaded ZnO (1 mol%). The reason for the enhancement ascribed to electron trap generated by the special 7f electronic configuration of Gd 3+ which could increase the separation of the photo induced electron hole pairs and promoted charge transfer within the nanostructures. The photoluminescence spectrum consists of peak at ∼363 nm, ∼452 nm and ∼545 nm, color co-ordinates (0.14665, 0.31283) and average correlated color temperature ∼28465 K. Therefore, Gd-loaded nanostructures can be exercised as prospective photocatalyst as well as phosphors in display applications. [ABSTRACT FROM AUTHOR]

Dy 3+ doped Mg 2 SiO 4 nanoparticles have been synthesized by the solution combustion method at 350 °C temperature. The crystallinity and changes of lattice parameters with the incorporation of the Dy 3+ ions are studied by means of Powder X-Ray Diffraction studies. Fourier transform infrared data indicate the formation of bonds and capping of the nanoparticles. Scanning electron microscopy pictures evident for the product is porous and agglomerated. The nano size of the product is confirmed by means of transmission electron microscopy. The characteristic emission peaks and the Judd–Ofelt intensity parameters of Mg 2 SiO 4 :Dy 3+ nanoparticles are studied. The emission can be tuned from green (0.238, 0.348) to white (0.276, 0.347) which indicates, the prepared phosphors can be effectively used for white light emitting diodes and biosensors. Further, the degradation of dyes is found to be enhancing in the presence of Dy 3+ ions due to suppress of the e − CB and h + VB recombination. [ABSTRACT FROM AUTHOR]

Photoluminescence and photocatalytic properties of Eu-doped ZnO nanoparticles (NPs) were synthesized by facile phyto route. XPS results demonstrated the existence of Eu 3+ as dopant into ZnO. Morphologies of the NPs were mainly dependent on Eu 3+ and Aloe vera gel. Red shift of energy band gap was due to the creation of intermediate energy states of Eu 3+ and oxygen vacancies in the band gap. PL emission of ZnO:Eu 3+ (1–11 mol%, 8 ml and 7 mol%, 2–12 ml) exhibit characteristic peaks of 5 D 0 → 7 F 2 transitions. From the Judd–Ofelt analysis, intensities of transitions between different J levels dependent on the symmetry of the local environment of Eu 3+ ions. CIE chromaticity co-ordinates confirm reddish emission of the phosphor. Further, NPs exhibit excellent photocatalytic activity for the degradation of Rhodamine B (94%) under Sunlight was attributed to crystallite size, band gap, morphology and oxygen vacancies. In addition, photocatalyst reusability studies were conducted and found that Eu-doped catalyst could be reused several times with negligible decrease in catalytic activity. The present work directs new possibilities to provide some new insights into the design of new phyto synthesized nanophosphors for display devices, photocatalysts with high activity for environmental clean-up and solar energy conversion. [ABSTRACT FROM AUTHOR]

MgO:Fe 3+ (0.1–5 mol%) nanoparticles (NPs) were synthesized via eco-friendly, inexpensive and simple low temperature solution combustion route using Aloe vera gel as fuel. The final products were characterized by SEM, TEM and HRTEM. PXRD data and Rietveld analysis revealed the formation of cubic system. The influence of Fe 3+ ion concentration on the structure morphology, UV absorption, PL emission and photocatalytic activity of MgO:Fe 3+ NPs were investigated. The yellow emission with CIE chromaticity coordinates (0.44, 0.52) and average correlated color temperature value was found to be 3540 K which corresponds to warm light of NPs. The control of Fe 3+ on MgO matrix influences the photocatalytic decolorization of methylene blue (MB) under UV light. The enhanced photocatalytic activity of MgO:Fe 3+ (4 mol%) was attributed to dopant concentration, effective crystallite size, textural properties, decreased band gap and capability for reducing the electron–hole pair recombination. Further, the trends of inhibitory effect in the presence of different radical scavengers were explored. These findings open up new avenues for the exploration of Fe-doped MgO in eco-friendly water applications and in the process of display devices. [ABSTRACT FROM AUTHOR]

Spherical shaped cerium dioxide (CeO 2 ) nanoparticles (NPs) were synthesized via bio mediated route using Leucas aspera (LA) leaf extract. The NPs were characterized by PXRD, SEM, UV–Visible techniques. Photoluminescence (PL), photocatalysis and antibacterial properties of NPs were studied. PXRD patterns and Rietveld analysis confirm cubic fluorite structure with space group Fm-3m . SEM results evident that morphology of the NPs was greatly influenced by the concentration of LA leaf extract in the reaction mixture. The band gap energy of the NPs was found to be in the range of 2.98–3.4 eV. The photocatalytic activity of NPs was evaluated by decolorization of Rhodamine-B (RhB) under UVA and Sun light irradiation. CeO 2 NPs show intense blue emission with CIE coordinates (0.14, 0.22) and average color coordinated temperature value ∼148,953 K. Therefore the present NPs quite useful for cool LEDs. The superior photocatalytic activity was observed for CeO 2 NPs with 20 ml LA under both UVA and Sunlight irradiation. The enhanced photocatalytic activity and photoluminescent properties were attributed to defect induced band gap engineered CeO 2 NPs. Further, CeO 2 with 20 ml LA exhibit significant antibacterial activity against Escherichia coli (EC) and Staphylococcus aureus (SA). These findings show great promise of CeO 2 NPs as multifunctional material for various applications. [ABSTRACT FROM AUTHOR]

We report the synthesis of Y 2 O 3 : Eu 3+ (1–11 mol%) nanoparticles (NPs) with different morphologies via eco-friendly, inexpensive and simple low temperature solution combustion method using Aloe Vera gel as fuel. The formation of different morphologies of Y 2 O 3 : Eu 3+ NPs were characterized by PXRD, SEM, TEM, HRTEM, UV–Visible and PL techniques. The PXRD data and Rietveld analysis confirms the formation of single phase Y 2 O 3 with cubic crystal structure. The influence of Eu 3+ ion concentration on the morphology, UV–Visible absorption, PL emission and photocatalytic activity of Y 2 O 3 : Eu 3+ nanostructures were investigated. Y 2 O 3 : Eu 3+ NPs exhibit intense red emission with CIE chromaticity coordinates (0.50, 0.47) and correlated color temperature values at different excitation ranges from 1868 to 2600 K. The control of Eu 3+ ion on Y 2 O 3 matrix influences the photocatalytic decolorization of methylene blue (MB) as a model compound was evaluated under UVA light. Enhanced photocatalytic activity of conical shaped Y 2 O 3 : Eu 3+ (1 mol%) was attributed to dopant concentration, crystallite size, textural properties and capability of reducing the electron–hole pair recombination. The trend of inhibitory effect in the presence of different radical scavengers followed the order SO 4 2− > Cl − > C 2 H 5 OH > HCO 3 − > CO 3 2− . These findings show great promise of Y 2 O 3 : Eu 3+ NPs as a red phosphor in warm white LEDs as well as eco-friendly heterogeneous photocatalysis. [ABSTRACT FROM AUTHOR]