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The population explosion and rapid economic development has led to tremendous increase in the per capita use of fossil fuel energy resulting in major environmental consequences. To tackle these significant energy and environmental concerns, semiconductor photocatalysis is viewed as a promising environmentally friendly and sustainable solution. The photocatalytic hydrogen evolution utilizes solar energy into clean hydrogen energy which makes it green, environmentally friendly and effective technique to meet energy demands. This process requires workable catalysts to reach a significant reaction rate because of their multiple electrons and multiple proton nature. Among various visible light active photocatalytic materials, metal molybdates have been reported as emerging class of materials owing to their outstanding features as stable crystal structure, photo-corrosion inhibition, high redox efficiency, low cost and toxicity and suitable band structure. The present research provides an extensive review of the most recent advances and new insights into the utilization of metal molybdates in photocatalytic clean energy production and environment challenges. This review article summarizes the recent progresses in advanced strategies applied in metal molybdate based photocatalysts to enhance the photocatalytic performance. The advanced strategies are categorized as control over morphology and surface modification, doping of heteroatom, co-catalyst loading, noble metal deposition and construction of heterojunction, which are devoted to photocatalytic H 2 production and CO 2 reduction and to overcome the fast recombination of charge carriers and increasing the light absorption capacity. The fabrication strategies of metal molybdates and based materials are discussed in detail, as well as their usage as catalysts for H 2 evolution and CO 2 reduction have been analysed. Metal molybdates are promising photocatalysts for addressing present environmental issues, and this work paves the way for future photocatalytic research and development, which may assist in the development of highly effective photocatalysts for sustainable energy needs. [Display omitted] • Metal molybdates as photocatalysts-Structure and properties. • Introduced the synthetic routes: Effect on properties and photocatalytic performance. • Discussed strategies to improve the photocatalytic potential of metal molybdates. • Application for superior hydrogen evolution and CO 2 conversion-Recent advances. • Fundamentals and bottlenecks along with future prospects are discussed. [ABSTRACT FROM AUTHOR]

Abstract We investigate the electrical transport and dielectric properties of the nanocrystalline BaCo 0.9 Mn 0.1 O 3-δ under 2H- and 12H-type hexagonal phases. Temperature dependent electrical transport properties under 2H- and 12H-type phases show semiconducting-like behavior above the magnetic transition. The numerical value of electrical resistivity of the 12H-type phase at low temperature is 10-fold higher than the 2H-type counterpart, following the trend of structural stacking sequence. The 12H-type phase exhibits rarely known characteristics of ferromagnetic-insulator. The conduction mechanism under both phases is studied using variable range and small polaron hopping conduction mechanism. The 12H-phase shows large magnetoresistance (∼60%) under an application of 5 T of magnetic field at 50 K. The relation between magnetization and electrical resistivity around the magnetic ordering temperature is studied. The relation has been used to correlate the magnetic entropy change derived by magnetization and electrical resistivity measurements. Temperature dependence and magnetic field induced dielectric permittivity of the 2H- and 12H-type hexagonal phases is studied around the magnetic ordering temperature. Both phases exhibit dielectric suppression by magnetic ordering. The field dependence dielectric behavior shows magnetocapacitance value of ∼4% for 2H-phase and ∼94% for 12H-phase at their magnetic ordering temperature under external magnetic field of 5 T. The existence of intrinsic magneto-dielectric coupling is studied under the framework of Ginzburg-Landau theory for ferroelectromagnet. The origin of extrinsic magneto-dielectric contribution is justified using combinational effect of large negative magnetoresistance and Maxwell-Wagner effect. The magnetic and electrical transport properties of the nanocrystalline BaCo 0.9 Mn 0.1 O 3-δ compound are also studied using density of states. Nanocrystalline BaCo 0.9 Mn 0.1 O 3-δ sample shows novel magnetic field-induced effect on the magnetic, electric and dielectric properties around the same temperature window which could be utilized for multi-functional applications. Highlights • Electrical transport and dielectric properties of nanocrystalline BaCo 0.9 Mn 0.1 O 3-δ. • Relation between magnetic and electrical transport properties. • Study of physical properties using density of states (DOS) plots. • Magnetoresistance and magnetocapacitance properties. [ABSTRACT FROM AUTHOR]

Abstract Indium tin oxide powders containing different amount of tin were prepared using a facile water based sol-gel procedure. The structural and microstructural properties have been analysed with X-ray diffractometer, FTIR-spectroscopy, XPS, TEM and EDX analysis. The nanocrystalline powders were used to fabricate Taguchi design based thick film sensors and their low concentration ammonia sensing (30 ppm) performance were evaluated in the operating temperature range of 200–400 °C. Indium tin oxide sensor having 20 wt% tin oxide showed the optimum response, ∼61% for 30 ppm ammonia at operating temperature of 300 °C. Pd incorporation led to a significant enhancement in sensing response (∼82%) at the same condition. A good sensing response (∼43%) was also observed even at very low ∼ 3 ppm of ammonia concentration. The interference of other gases was almost insignificant. The sensor was stable as reflected from the observation of negligible decrease in the sensing performance of sample up to 90 days period. The sensing mechanism for enhancement has also been explained. Graphical abstract Image 1 Highlights • Different compositions of indium tin oxide were prepared using a unique procedure. • I 80 T 20 O sensor reveals optimum sensing response, ∼61% towards 30 ppm NH 3 at 300 °C. • 1 wt% Pd incorporation enhanced the sensitivity by ∼20%. • The sensor can detect very low concentration of NH 3 with reproducible performance. • It is also very stable and selective. [ABSTRACT FROM AUTHOR]

Nanocrystalline BaCo 0.90 Mn 0.10 O 3-δ (BCMO) was synthesised under normal atmospheric condition using sol-gel method. The X-ray diffraction patterns show the crystal structure changes from 2H- to 12H-type hexagonal phase depending on annealing temperature. The 2H-type hexagonal phase was observed for 900 °C annealed BCMO and 12H-type phase was formed for 1100 °C annealed BCMO sample. Temperature dependence of the zero-field-cooled and field cooled magnetization data shows the ferromagnetic to paramagnetic (FM-PM) ordering at ∼49 K in a 12H-type phase, whereas weak ferromagnetic ordering is observed in 2H-type phase. The saturation magnetization increases as phase changes from 2H to 12H type-hexagonal phase. The magnetocaloric effect (MCE) was studied near the magnetic ordering temperature for both type+s of phases (2H and 12H). The maximum magnetic entropy changes (|ΔS M max |) were found to be 0.28 Jkg −1 K −1 and 2.50 Jkg −1 K −1 for a magnetic field change of 5 T for 2H- and 12H-type phases sample respectively. The critical exponent and theoretical analysis of the MCE using Landau theory of phase transition confirm that the contributions to the free energy in the presence of ferromagnetic clusters are strongly influencing the MCE by coupling with the order parameter around the ordering temperature for 12H-type hexagonal phase sample. [ABSTRACT FROM AUTHOR]

Poled and unpoled BaTiO 3 nanoparticles (NPs) were coated onto the cotton surface by screen printing. The piezocatalytic antibacterial and dye degradation activities of the coated samples were assessed by ultrasonication method. The prepared samples were tested for reduction against E. coli and S. aureus bacteria. After 2 h contact period, E. coli and S. aureus were reduced by 99.8% and 97.7%, respectively, by the poled BT embedded fabric, while unpoled BT-NPs loaded cotton reduced these bacteria by 96.5% and 95.2%, respectively. In contrast to the 60% and 29% degradation of Methylene Blue (MB) dye observed for unpoled BT-NPs coated cloth and pristine cotton in 75 min, respectively, poled BT-NPs coated fabric degraded MB dye by 82%. • Poled and unpoled BaTiO 3 nanoparticles were loaded onto the cotton fabric. • Piezocatalytic antibacterial and dye degradation activities of the coated samples were assessed. • After 2 h contact period, poled BaTiO 3 coated cotton reduced E. coli and S. aureus by 99.8% and 97.7%, respectively. • 82% degradation of MB dye was demonstrated by poled BaTiO 3 coated fabric in 75 min [ABSTRACT FROM AUTHOR]

In the present study, Mg-3Al- x La ( x ∼ 1, 2.5, 4) alloys were synthesized using disintegrated melt deposition technique followed by hot extrusion. These alloys were critically investigated for microstructure, tensile and compression properties, damping properties, microhardness and fracture morphology. The grain size of Mg-3Al was significantly reduced by the addition of Lanthanum (La) and it was minimum for 2.5 La-containing alloy (∼5.8 μm, 25% of pure Mg grain size). SEM and X-ray studies revealed the suppression of β-eutectic phase ( M g 17 A l 12 ) due to the formation of A l 11 L a 3 , A l 2 L a , and A l 2.12 L a 0.88 intermetallic phases. Microhardness increased with the addition of La and it was recorded highest for Mg-3Al-4La (122 H v ). Mechanical characterization results show that the tensile yield strength (TYS), ultimate tensile strength (UTS) and ductility for Mg-3Al-2.5La alloy are the best reported values till date among all the available reports for this system of alloy (TYS ∼ 160 MPa, UTS ∼ 249 MPa and fracture strain ∼22%). Results of damping measurement revealed an increase in damping of Mg-3Al alloy due to the presence of La (2.5%). Compression results show that the addition of La to Mg-3Al caused gradual decrease in compression yield strength and elongation. [ABSTRACT FROM AUTHOR]

Structural and magnetic properties of thermal plasma synthesized Fe 1− x Ni x ( x = 0.25, 0.33, 0.50, 0.67 and 0.75) alloy nanoparticles have been investigated using x-ray diffraction, neutron diffraction, transmission electron microscopy, scanning electron microscopy, dc magnetization, and Mössbauer spectroscopy techniques. High temperature gas phase nucleation and growth environment inside thermal plasma reactor facilitate stabilization of the disordered γ-FeNi ( fcc ) phase throughout (except for x = 0.25) the composition range under investigation. For x = 0.25 composition, a small (∼8%) amount of the disordered bcc phase along with prominent fcc (∼92%) phase is present, as inferred from the neutron diffraction data analysis. The spherical shaped nanoparticles possess high crystallinity. The average crystallite size (in 30–40 nm range) as well as particle size distribution show insignificant change as a function of composition. The observed value of the saturation magnetic moment for these nanoparticles are very close to that for their bulk counterparts, indicate highly crystalline nature of the thermal plasma synthesized nanoparticles. Room temperature Mössbauer spectroscopic data reveals that the alloy nanoparticles contain two different sites for Fe corresponding to high moment/low moment states. The neutron diffraction data indicates ferromagnetic ordering for all the compositions of the series. The average magnetic moments/f.u., derived from neutron diffraction and dc magnetization, are found to match with each other as well as with the values reported in the literature for bulk Fe 1− x Ni x alloys. The highest ordered magnetic moment was found to be 1.4 μ B per f.u. for Fe 0.50 Ni 0.50 composition. Overall, thermal plasma based synthesis is found to be an excellent route to produce high-quality nanoparticles of the binary metallic alloys. [ABSTRACT FROM AUTHOR]

Abstract: Polycrystalline samples of single-phase co-doped (La3+, Lu3+) in Bi0.95− x La0.05Lu x FeO3 (x =0.03, 0.05 and 0.07) (grain size ∼0.5μm; tolerance factor ∼0.88) were prepared by solid state reaction of oxides, followed by rapid quenching of samples. Magnetic measurements show weak ferromagnetic-antiferromagnetism (WFM) nature at room temperature but ferromagnetic nature at ∼5K. Field cooled curves reveal spin reorientation in the system at lower temperature as shown by the peaks at ∼145 and ∼140K for x =0.03 and 0.07, respectively. Dielectric measurement shows relaxor type of phase transition for x =0.07. The magnetocapacitance was found to be enhanced (∼3 times than that of BiFeO3) due to co-doping of (La3+, Lu3+) in BiFeO3 ceramic showing the coupling effect between magnetic and electric behaviors which occurs through the lattice distortion. [Copyright &y& Elsevier]

Abstract: Optical, magnetocapacitance and dielectric properties of different composite films of BiFeO3–poly(vinylidene-fluoride) (with concentration of BiFeO3; 70, 60, 50 and 40wt%) are reported here for first time. The grain size was observed to be ∼50nm by using atomic force microscopy. A peak in refractive index appears at ∼455nm, which is found to be shifting towards lower wavelengths, while simultaneously the value of the optical energy band gap is found to increase with an increase in the concentration of PVDF in the composite. It was observed that PVDF, which works as matrix, increases the magnetocapacitance. The magnetocapacitance (MC) of BFO60 (BiFeO3; 60wt%) was found higher than Nb doped BiFeO3, which may be useful for device applications. [Copyright &y& Elsevier]

The low temperature lattice structure and magnetic properties of Co 2.75 Fe 0.25 O 4 ferrite have been investigated using experimental results from synchrotron x-ray diffraction (SXRD), dc magnetization, ac susceptibility, neutron diffraction and neutron depolarization techniques. The samples have been prepared by chemical co-precipitation of the Fe and Co nitrates solution in high alkaline medium and subsequent thermal annealing of the precipitates in the temperature range of 473–1173 K. Rietveld refinement of the SXRD patterns at room temperature indicated two-phased cubic spinel structure for the samples annealed at temperatures 473–873 K. The samples annealed at temperatures 973 K and 1173 K (CF90) have shown single phased lattice structure. Refinement of the neutron diffraction patterns in the measurement temperature range 5–300 K confirmed the antiferromagnetic (AFM) Co 3 O 4 and ferrimagnetic (FIM) Co 2.75 Fe 0.25 O 4 phases for the sample annealed at 873 K and single FIM phase of Co 2.75 Fe 0.25 O 4 for the CF90 sample. Magnetic measurements have shown a non-equilibrium magnetic structure, consisting of high temperature FIM phase and low temperature AFM phase. The magnetic phases are sensitive to magnetic fields, where high temperature phase is suppressed at higher magnetic fields by enhancing the low temperature AFM phase, irrespective of annealing temperature of the samples. • A detailed study is presented on lattice structure and magnetic properties. • Single-phased and two-phased lattice structure are identified in spinel oxide. • Ferrimagnetic properties are enhanced in spinel oxide close to Co 3 O 4. • The effects of AFM and ferrimagnetic clusters are seen in the temperature scale. • Multiple magnetic transitions are observed in no-equilibrium spinel structure. [ABSTRACT FROM AUTHOR]

In this work, a carbon quantum dots (CQDs) decorated dual Z-scheme CeO 2 /g-C 3 N 4 /V 2 O 5 heterojunction (CCGV) was rationally synthesized by simple hydrothermal method. The crystal structure, morphology, and optical properties of the photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy. CCGV catalyst shows high visible absorption, including near infra-red region and solar light via two-channel charge transfer (dual Z-scheme), reduced recombination, and up-conversion effect of CQDs. The heterojunction was used for visible assisted photo-reduction of carcinogenic hexavalent chromium ions (Cr(VI)) with a 99% reduction in 100 min without any sacrificial agent or hole scavenger. The reaction becomes more rapid with tartaric acid as a scavenger with a complete reduction in just 30 min under visible light. Photogenerated electrons are the dominant active species, followed by ●O 2 −, as revealed by the scavenging experiments. The use of sacrificial agents and scavengers suggests that photogenerated electrons were the dominant active species followed by ●O 2 − radicals. The electrochemical impedance spectroscopy and photoluminescence results confirm highly reduced recombination, high charge separation, and charge transfer capacity in the dual Z-scheme heterojunction. The conduction band edges of CeO 2 and V 2 O 5 (which are protected by the dual charge transfer) have an appropriate potential for the rapid reduction of hexavalent chromium. The XPS scan of the catalyst after separation shows the presence of Cr in the +3 oxidation state, suggesting complete photo-reduction. This study is promising for developing wide spectrum active simple heterojunction photocatalysts for pollutant removal with high efficiency. Image 1 • Dual Z-scheme CQDs @ CeO 2 /g-C 3 N 4 /V 2 O 5 heterojunction (CCGV) was successfully prepared. • CCGV junction shows efficient photoreduction of carcinogenic hexavalent chromium. • Visible, NIR and solar activity with high visible capture. • Mechanistic approach-Scavenging and Sacrificial agents. • Comparison between conventional and dual Z-scheme-high potential bands. [ABSTRACT FROM AUTHOR]

The present paper reports on a unique eco-friendly bio-synthesis process of tin oxide using water extract of soaked kabuli chickpea seeds as natural binder. The structural, microstructural and CO sensing properties of the newly synthesized tin oxide were compared with those of conventional sol–gel and sonochemical processes. XRD results of the bio-synthesized material revealed the formation of single tetragonal phase of SnO 2 similar to sol–gel and sonochemical processes. The bio approach led to the formation of finer nanoparticales with a higher specific surface area ∼ 60 m2 /gm compared to the others. The average sizes of tin oxide nanoparticles as observed from TEM images were about 35 nm, 15 and 6 nm for the sonochemical, sol-gel and biosynthesis respectively. These tin oxide powders were used to fabricate Taguchi based sensors and their CO sensing performance were evaluated. The biosynthesized tin oxide sensor showed ∼53% sensing performance for 30 ppm CO which was better than sol-gel (∼44%) or sonochemical (∼42%) tin oxides operating at similar condition. The reported results suggest that the biosynthesis is a promising cost effective method to prepare nanocrystalline SnO 2 for sensing application. Image 1 • Pure tin oxide powder of average particle size ∼6 nm was prepared using water extract of kabuli chickpea seeds. • The structural and morphological properties of this were compared with sol-gel and sonochemical processes. • The sensor fabricated from biosynthesized tin oxide revealed the best sensing performance, ∼53% on exposure of 30 ppm CO. • This sensor was stable and able to detect very low concentration (∼3 ppm) of CO with reproducible performance. • The mechanism for the formation of nanoparticles and better sensitivity has been illustrated. [ABSTRACT FROM AUTHOR]

The control of polarization rotation (PR) is a key issue of applying undoped zinc oxide (ZnO) as information storage devices. A systematic study of ZnO thin films by conducting piezoresponse force microscopy (PFM) technique on samples with different electrodes, film thicknesses, and deposition oxygen partial pressures, P O 2 allows disclosing the possible factors those affecting the PR behavior. The results clearly indicate that higher work function conductive material, such as Pt, is a promising candidature as the top electrode and bottom electrode to ensure the PR occur and maintain in ZnO films. From the effects of film thickness study, PR behavior can be observed in film downscaled to 15 nm. However, in order to avoid current leakage and maintain the rotated polarization state, thicker film with about 240 nm is preferred. In addition, in the film deposited with a low P O 2 (>5 × 10−6 Torr), more atomic point defects such as oxygen vacancy may lead the sample into a large leakage current and deteriorate the PR behavior. Hence, by this systematic study, it is proved that the PR behavior of undoped ZnO thin films can be optimized with proper deposition parameters. Image 1 • Possible factors affecting the PR behavior are studied comprehensively. • Pt is a promising electrode candidature for PR behavior comparing with Au and ITO. • Unambiguous PR behavior is found in film with a thickness reduced to 15 nm. • P O 2 below 5 × 10−6 Torr might hinder the PR behavior. [ABSTRACT FROM AUTHOR]

A simple, cost effective production approach having high stability is pertinent to any organic-inorganic perovskite solar cells. The main focus of the present work has been to formulate and estimate the stability of CH 3 NH 3 PbBr 3 micro-cubes and nanoparticles based perovskite solar cells. Firstly, novel synthesis route has been introduced for the preparation of CH 3 NH 3 Br (MABr) electrolyte salt which is less time consuming, as well as cost effective than pristine methods. We also reported a facile single solution process to grow large scale CH 3 NH 3 PbBr 3 (MAPbBr 3 ) hybrid perovskite micro-cubes and nano-particles. The effect of different size (micro-cube & nano-particles) of perovskite material on structural, optical, thermal stability and degradation kinetics has been examined. X-ray diffraction spectra of MAPbBr 3 perovskite reflect high crystallinity and cubic structure of the material at the room temperature. The surface morphology of micro-cubes and nano-particle MAPbBr 3 has been obtained from scanning electron microscope (SEM). Broad absorption spectrum has found in the visible region with high absorption coefficient and PL spectra show the green emission which is in good agreement with the optical band gap of MAPbBr 3 from absorption measurements. With decreasing the size of perovskite materials, band gap and emission spectra tuned towards the blue region. The simultaneous thermal analysis (STA) study indicates towards the more thermal stability of micro-cubes structures than nanoparticles material while the change in enthalpy (ΔH) and specific heat capacity (ΔCp) of nano particle have increased by reducing the particle size of perovskite due to modification of endothermic peaks. [ABSTRACT FROM AUTHOR]

This paper presents some preliminary investigation of electromagnetic radiation (EMR) emissions from (1-x)(Bi 0.5 Na 0.5 TiO 3 )–x(BaTiO 3 ) (x = 0.04, 0.05, 0.06, 0.07 & 0.08) lead-free piezoelectric ceramics. Compositions near the morphotropic phase boundary 0.94(Bi 0.5 Na 0.5 TiO 3 )–0.06(BaTiO 3 ) (BNT-6BT) are studied. The electromagnetic radiations were detected with the help of non–contacting loop antenna placed around the sample. EMR voltage detection was done simultaneously when the piezoelectric material was subjected to alternating electric field. Digital storage oscilloscope was used to measure the EMR voltage. At highest applied alternating electric field of 5.8 kV/cm EMR Signal of 17.6 V was detected for 0.95(Bi 0.5 Na 0.5 TiO 3 )–0.05(BaTiO 3 ) (BNT-5BT). Higher frequency of the electric field leads to the higher acceleration of the dipoles of the piezoelectric material and thus leads to the higher amplitude of EMR. The EMR Voltage is observed to be proportional to the polarization and this can lead to the development of new technique of measuring extent of polarization. Also the EMR phenomenon can be used to develop sensors for non-contact excessive deformation measurement. [ABSTRACT FROM AUTHOR]

• Sugar derived C/MnO 2 composite studied as an electrode material for supercapacitors. • C/MnO 2 exhibits the specific capacitance of 416 F g−1 , stable over 5000 cycles. • C/MnO 2 delivers an energy density of 60 Wh kg−1 at power density of 201Wkg−1. • Presence of sugar derived carbon enhances the diffusion kinetics of C/MnO 2. Schematic diagram illustrates the syntheis of sugar derived Carbon/MnO 2 composite and their physical and electrochemical performances [Display omitted] Herein, we present an efficient and simple method to develop a 3D-Carbon /MnO 2 (C/MnO 2) composite active material for high-performance supercapacitors. MnO 2 nanorods are synthesized by the hydrothermal process, and corresponding carbon composite is synthesized from table sugar precursors using the combustion process. MnO 2 has rod-like morphologies and forms 3D electrode architectures with carbon, and contains about 5–10 nm of carbon coating. The charge storage behavior studied by galvanostatic charge-discharge cycling shows capacitance of 416 F g−1 at 1 A g−1 with capacitance retention of 90% after 5000 cycles. The superior electrochemical performance is attributed to the one–dimensional ion transport of Mn ion, the in-situ 3D electrode architecture, and carbon coating that enhances the conductivity and the surface area of MnO 2. C/MnO 2 composite exhibits an energy density of 60 Wh kg−1 with a power density of 201 W kg−1. The combined pseudocapacitive behavior of MnO 2 and electric double-layer capacitors property of carbon exhibits significant electrochemical performance in the aqueous electrolyte. The synthesis approach uses environment benign active materials with the low cost of electrode fabrication provides an alternative route for the development of high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

Highlights: [•] Multiple magnetic phases of NdMn1.4Co0.6Si2 compound have been investigated. [•] Five distinct magnetic phases are found with temperature. [•] Collinear AFM, incommensurate AFM, mixed FM and AFM structures found. [•] Nd site contributes distinctly to the observed magnetic phases at low temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] The nanocomposite material PANI–ZSP has been synthesized by sol–gel method. [•] The PANI–ZSP exhibits decent ion exchange behaviour. [•] The various physiochemical properties were investigated. [•] PANI–ZSP was found to be efficient photocatalyic agent under solar light. [•] The nanocomposite PANI–ZSP has good thermal stability. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fe doped ZnO nanoparticles have been successfully synthesized by simple sol–gel route. [•] Solubility limit of Fe in ZnO matrix is found to be less than 5%. [•] Fe doped ZnO nanoparticles are better photocatalytic activist than ZnO. [•] Prepared particles possess intrinsic room temperature ferromagnetism. [ABSTRACT FROM AUTHOR]

Highlights: [•] We synthesized a novel nanocomposite of Fe0.01Ni0.01Zn0.98O and polyaniline. [•] Its photocatalytic behavior was compared with Fe0.01Ni0.01Zn0.98O nanoparticles. [•] A whopping 99.47% dye removal was achieved in 5h for the composite. [•] The composite has higher dc conductivity than nanoparticles. [•] Remarkable antibacterial activity is achieved against E. coli. [ABSTRACT FROM AUTHOR]

Pure and zinc-doped cobalt oxide heterojunction devices on n-type silicon substrates have been fabricated via sol-gel spin coating deposition. The fabricated devices have been characterized by XRD, Raman spectroscopy, FESEM, and EDS elemental mapping. The fabricated heterojunction devices show non-linear I-V characteristics, which suggests their diodic behavior. A blend of mathematical and physical methods that are based on the Lambert W function and the modified Shockley equation has been used to examine the performances of the devices. The UV sensing measurements were conducted on the devices under zero bias conditions while they were subjected to UV light with wavelengths of 365 and 254 nm. The study has indicated that Co 3 O 4 in its pure form does not exhibit activity towards either UV wavelength. However, the introduction of Zn2+ into Co 3 O 4 results in a notably substantial photoresponse of approximately 978 %, 1393 %, and 2400 % for Zn2+ concentrations of 5 %, 15 %, and 30 %, respectively, when exposed to 365 nm UV radiation. The responsivity value of the fabricated devices was found to increase from 0.026 mA/W to 15.82 mA/W with an increase in Zn2+ from 5 % to 30 %. Detectivity and EQE values of the devices also demonstrate remarkable increase from 7.50 × 108 cmHz1/2/W (5 % Zn2+) to 2.86 × 1010 cmHz1/2/W (30 % Zn2+) and from 0.009 % (5 % Zn2+) to 5.39 % (30 % Zn2+) respectively. The increase in Zn2+ concentration also increases the linear dynamic range (LDR) value from 20.65 dB to 27.96 dB. • Sol-gel spin coating technique was used to fabricate p-Co 3 O 4 /n-Si and p-ZnCo 2 O 4 /n-Si heterojunctions. • Ultra-violet photodetectors were fabricated using the metal oxide heterojunctions. • Embedment of Zn2+ ions in Co 3 O 4 thin films give rise the UV photoconductivity. • Device performance parameters like responsivity, detectivity, EQE, and LDR were studied. • Current-voltage characteristics were theoretically fitted modified Shockley equation. [ABSTRACT FROM AUTHOR]

Nickel sulfide(NiS) nano-particles are used in the solar absorber medium of thin film organic solar cell (TFOSC) to aid in harvesting solar energy. Solution-processed TFOSCs were fabricated using poly-3-hexylthiophene (P3HT) and (6-6) phenyl-C61-butyric acid methyl ester (PCBM) blend photo-active layer with or without NiS nano-particles(NPs). The new solar cells showed enhanced opto-electronic properties by the incorporation of NPs. The experimental data suggest that the device performances have been influenced by the concentration of NiS nano-particles in the absorber layer. Consequently, the power conversion efficiency(PCE) of the solar cell has improved by 93% from the reference cell, at 1% optimum concentration of NiS by weight. The best PCE recorded in this investigation was 4.63%, which is an important development in an ambient environment preparation condition. The effect of the metal nano-particles clearly demonstrated in this investigation in terms of enhanced short circuit current (J sc) and PCE, which are an indicators of improved exciton dissociation and charge transportation processes in the medium. The results will be discussed by way of optical and electrical properties of the solar absorber films. • Nickel sulfide nano-particle is successfully used in solar energy harvesting using TFOSC. • Well aligned polycrystalline structure have been observed from newly synthesized NiS. • Local surface plasmon resonance of NiS in polymers blend matrix is responsible for high photo-current. [ABSTRACT FROM AUTHOR]