High Energy Density Achieved in Novel Lead-Free BiFeO3-CaTiO3 Ferroelectric Ceramics for High-Temperature Energy Storage Applications.

The development of high-performance electrostatic energy storage dielectrics is essential for various applications such as pulsed-power technologies, electric vehicles (EVs), electronic devices, and the high-temperature aviation sector. However, the usage of lead as a crucial component in conventional high-performance dielectric materials has raised severe environmental concerns. As a result of this, there is an urgent need to explore lead-free alternatives. Ferroelectric ceramics offer high energy density but lack stability at high temperatures. Here we present a lead-free (1 - x)BiFeO3-xCaTiO3 (x = 0.6, 0.7, and 0.8; BFO-CTO) ceramic capacitor with low dielectric loss, high thermal stability, and high energy density up to ∼200 °C. The introduction of CTO (x = 0.7) to the BFO matrix triggers a transition from the normal ferroelectrics to the relaxor ferroelectrics state, resulting in a high recoverable energy density of 1.18 J cm-3 at 190 °C with an ultrafast dielectric relaxation time of 44 µs. These results offer a promising, environmentally friendly, high-capacity ceramic capacitor material for high-frequency and high-temperature applications.

Rice (Oryza sativa) alleviates photosynthesis and yield loss by limiting specific leaf weight under low light intensity.

The physiological mechanisms of shade tolerance and trait plasticity variations under shade remain poorly understood in rice (Oryza sativa L.). Twenty-five genotypes of rice were evaluated under open and shade conditions. Various parameters to identify variations in the plasticity of these traits in growth irradiance were measured. We found wide variations in specific leaf weight (SLW) and net assimilation rate measured at 400µmolm-2 s-1 photosynthetic photon flux density (PPFD; referred to as A 400 ) among the genotypes. Under shade, tolerant genotypes maintained a high rate of net photosynthesis by limiting specific leaf weight accompanied by increased intercellular CO2 concentration (C i ) compared with open-grown plants. On average, net photosynthesis was enhanced by 20% under shade, with a range of 2-30%. Increased accumulation of biomass under shade was observed, but it showed no correlation with photosynthetic plasticity. Chlorophyll a /b ratio also showed no association with photosynthetic rate and yield. Analysis of variance showed that 11%, 16%, and 37% of the total variance of A 400 , SLW, and C i were explained due to differences in growth irradiance. SLW and A 400 plasticity in growth irradiance was associated with yield loss alleviation with R 2 values of 0.37 and 0.16, respectively. Biomass accumulation was associated with yield loss alleviation under shade, but no correlation was observed between A 400 and leaf-N concentration. Thus, limiting specific leaf weight accompanied by increased C i rather than leaf nitrogen concentration might have allowed rice genotypes to maintain a high net photosynthesis rate per unit leaf area and high yield under shade.

Yield-enhancing SPIKE allele from the aus-subtype indica rice and its allele specific codominant marker.

Improving spikelet number without limiting panicle number is an important strategy to increase rice productivity. In this study, a spikelet number enhancing SPIKE-allele was identified from the aus subtype indica rice, cv. Bhutmuri, which has an identical japonica like corresponding sequence including a retrotransposon sequence, usually absent in indica genotypes, like IR64. An allele-specific singletube PCR-based codominant marker targeting an A/G single-nucleotide polymorphism (SNP) at the 3'UTR was identified for easier genotyping. The yield enhancing ability of the Bhutmuri-SPIKE allele carrying RILs and NILs over IR64-SPIKE allele carrying alleles was due to increased number of filled grains/panicle. More than three times higher abundance of SPIKE transcripts was observed in Bhutmuri and NILs carrying this allele compared with IR64 and its allele carrying NILs. Higher rate of photosynthesis at more than 900 µmolm-2s-1 light intensity and more than six small vascular bundles between the two large vascular bundles in the flag leaves of Bhutmuri and its allele carrying NILs were also observed. The identified SPIKE allele and the marker associated with it will be useful for increasing the productivity of rice by marker-assisted breeding.

A perfect PCR based co-dominant marker for low grain-arsenic accumulation genotyping in rice.

The development of low arsenic-accumulating varieties for the contaminated areas is one of the best options for reducing the dietary exposure of arsenic to human population through rice. In this study, grain-arsenic content in one hundred genotypes revealed a large variation ranging from 0.05 mg/kg to 0.49 mg/kg. Compared to high accumulating variety, Shatabdi, 6-8 times the transcript upregulation of Arsenic sequestering ATP binding cassette C1 type gene (ABCC1), was observed in first internode of low accumulating variety Gobindabhog when 5 mg/kg of arsenite was present in soil. A comparison of the genomic sequence of OsABCC1 identified 8 SNPs between the two genotypes; 5 in introns and 3 silent mutations in exons. We identified a PCR based co-dominant marker targeting an SNP (T/G) between the two genotypes, which clearly distinguished 100 genotypes into low (mean 0.14 mg/kg) and high (mean 0.35 mg/kg) accumulating groups. All aromatic genotypes, either long or small grain, carry the Gobindabhog-type ABCC1 allele and are low accumulators of arsenic. Gobindabhog allele carrying 62 RILs and NILs showed almost 40-50% less As-accumulation in grains relative to 84 RILs and NILs carrying Shatabdi type ABCC1-allele. The marker will be useful in introgression of low accumulating allele of OsABCC1 into high yielding photoperiod insensitive varietal backgrounds more easily and accurately.

Identification and analysis of low light tolerant rice genotypes in field conditions and their SSR-based diversity in various abiotic stress tolerant lines.

The yield potentiality of kharif rice is not completely used even under well-irrigated agro-ecosystem, mainly due to low irradiance by overcast cloud throughout the growing season in eastern India. We observed more than 50% yield reduction compared to the performance of 100 high-yield genotypes for consecutive three years both under open and 30-35% reduced light intensity, mainly by 34%, 25% and 12% reduction of panicle number, grains per panicle and test weight. As per the analysis of variance, genotypic variance explained 39% of the total yield-variation under shade with 58% heritability. Overall, the maintenance of equal panicle per plant in both open and shade has the highest association with shade tolerance. Purnendu, Sashi and Pantdhan19 showed less than 28% yield-reduction by maintenance or even by increasing grain numbers under shade and test weight. On the other hand, maintenance of an equal number of panicle under both situations was the key to the tolerance of Bhasamanik, Sasarang, Rudra and Swarnaprabha. As compared to open, we noticed the improvement of chlorophyll a and b under shade but saw a poor correlation with the shade tolerance index. Comparing the net photosynthesis rate (Pn) in eight genotypes, we found the best tolerant line ranked last with least Pn at low light intensity (400 µmol m-2 s-1). We also identified diverse parental combinations between newly identified shade tolerant and abiotic stress tolerant high-yielding rice lines following diversity analysis using 54 simple-sequence repeats. Thus, the selected tolerant lines from a large set of genotypes with different adjustment ability to keep up high yield under low light intensity can be used for physiological, molecular analysis as well as pyramiding of traits.

Thermoresponsive polymer gated and superparamagnetic nanoparticle embedded hollow mesoporous silica nanoparticles as smart multifunctional nanocarrier for targeted and controlled delivery of doxorubicin.

The design and development of drug-delivery nanocarriers with high loading capacity, excellent biocompatibility, targeting ability and controllability have been the ultimate goal of the biomedical research community. In this work, we have reported the synthesis and characterization of novel and smart thermoresponsive polymer coated and Fe3O4 embedded hollow mesoporous silica (HmSiO2) based multifunctional superparamagnetic nanocarriers for the delivery of doxorubicin (Dox) for cancer treatment. P(NIPAM-MAm) coated and Fe3O4 nanoparticle (NP) embedded hollow mesoporous silica nanocomposite (HmSiO2-F-P(NIPAM-MAm)) was prepared by the in situ polymerization of NIPAM and MAm monomers on the surface of hollow mesoporous silica NPs (HmSiO2) in the presence of Fe3O4 NPs, oxidizer and crosslinker. TEM analysis showed nearly spherical morphology of HmSiO2-F-P(NIPAM-MAm) nanocarrier with a diameter in the range of 100-300 nm. The coating of P(NIPAM-MAm) layer and embedding of Fe3O4 NPs on the surface of the HmSiO2 NPs was revealed by HRTEM analysis. XRD and FTIR analysis also confirmed the presence of P(NIPAM-MAm) shells and Fe3O4 NPs on hollow mesoporous silica NPs. VSM analysis suggested the superparamagnetic nature of HmSiO2-F-P(NIPAM-MAm) nanocarrier. DSC analysis of HmSiO2-F-P(NIPAM-MAm) nanocarrier showed a phase transition at the temperature of ∼38 °C. The prepared HmSiO2-F-P(NIPAM-MAm) nanocarrier was investigated for its suitability for drug-delivery application using doxorubicin as the model drug by an in vitro method. The encapsulation efficiency and encapsulation capacity were found to be 95% and 6.8%, respectively. HmSiO2-F-P(NIPAM-MAm)-Dox has shown a pH and temperature-dependent Dox release profile. A relatively faster release of Dox from the nanocarrier was observed at temperature above the lower critical solution temperature (LCST) than below the LCST. HmSiO2-F-P(NIPAM-MAm) nanocarrier was found to be biocompatible in nature. In vitro cytotoxicity studies against Hela cells suggested that the HmSiO2-F-P(NIPAM-MAm)-Dox nanocomposite nanocarrier has good anticancer activity. In vitro cellular uptake study of HmSiO2-F-P(NIPAM-MAm)-Dox nanocomposite nanocarrier demonstrated its good internalisation ability into Hela cells. Thus, the prepared nanocomposites show potential as nanocarrier for targeted and controlled drug delivery for cancer treatment.

Colossal piezomagnetic response in magnetically pressed Zr+4 substituted cobalt ferrites.

A remarkable 111% increase in magnetostriction (λ) and 435% increase in strain sensitivity (dλ/dH) (compared to normally compacted (NC) unsubstituted CoFe2O4 (CFO)) of Zr+4 doped CFO sample, Co1.2Zr0.2Fe1.6O4, prepared by magnetic field assisted compaction, have been reported in this study. Magnetic field assisted compaction (MC) has been employed to process Zr-doped cobalt ferrites, Co1+xZrxFe2-2xO4 (0 ≤ × ≤ 0.4), to further improve the magnetoelastic properties. Saturation magnetization (M S ) and coercivity (H C ) increase from ~426 kA/m and ~4.4 kA/m respectively, for x = 0, to ~552 kA/m and ~7.11 kA/m respectively for x = 0.2. Dramatic increase in λ was observed for MC samples (~ -360 ppm and ~-380 ppm for x = 0 and x = 0.2 respectively) compared to the NC samples (~-181 ppm and ~-185 ppm for x = 0 and x = 0.2 respectively). A remarkable quadruple increase in dλ/dH was observed in Zr-doped (x = 0.2) cobalt-ferrite (~4.3 × 10-9 A-1m) compared to that of unsubstituted cobalt-ferrite (~1.24 × 10-9 A-1m), while a fivefold increase in dλ/dH was observed for magnetically compacted (MC) Zr doped cobalt ferrite (x = 0.2) (~4.3 × 10-9 A-1m) compared to normal compacted (NC) unsubstituted cobalt ferrite (~0.8 × 10-9 A-1m).

Magnetically recyclable Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O nano-photocatalyst: structural, optical, magnetic and photocatalytic properties.

A novel visible light active and magnetically separable nanophotocatalyst, Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O (denoted as NZF@Z), with varying amount of Ni0.5Zn0.5Fe2O4, has been synthesized by egg albumen assisted sol gel technique. The structural, optical, magnetic, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), UV-visible (UV-Vis) spectroscopy, and vibrating sample magnetometry (VSM) techniques. Powder XRD, TEM, FTIR and energy dispersive spectroscopic (EDS) analyses confirm coexistence of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O phases in the catalyst. Crystallite sizes of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O in pure phases and nanocomposites, estimated from Debye-Scherrer equation, are found to be around 15-25 nm. The estimated particle sizes from TEM and FESEM data are ∼(22±6) nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra, of Zn0.95Ni0.05O, 15%NZF@Z, 40%NZF@Z and 60%NZF@Z are 2.95, 2.72, 2.64, and 2.54 eV respectively. Magnetic measurements (field (H) dependent magnetization (M)) show all samples to be super-paramagnetic in nature and saturation magnetizations (Ms) decrease with decreasing ferrite content in the nanocomposites. These novel nanocomposites show excellent photocatalytic activities on Rhodamin Dye.

Synthesis and characterization of structural, optical, thermal and dielectric properties of polyaniline/CoFe2O4 nanocomposites with special reference to photocatalytic activity.

In this study we have synthesized polyaniline/CoFe2O4 nanocomposites (PANI@CFs) by in situ polymerization method with different amounts of the CoFe2O4 nanoparticles NPs (CF-NPs) (0.5 g and 1.0 g). The structural optical, thermal and dielectric properties of the as synthesized PANI@CFs were studied. The XRD analysis ensures that CF-NPs have a single phase spinel structure. The XRD and EDAX results confirmed that the CF-NPs were successfully incorporated in the PANI matrix. The crystalline size analysis revealed that the size increased with increasing CF-NPs amount in the PANI@CFs, because of the aggregation effect. TGA exhibited an enhanced thermal stability of the PANI@CFs as compare with PANI owing to the strong interaction between the CF-NPs and polymer matrix. The energy band gaps as calculated through the Tauc relation were found to be gradually higher with the increasing the amount of CF-NPs in PANI@CFs. The dielectric constants (ε', ε″), dielectric loss (tanδ) and AC conductivity (σac) were studied as the function of frequency and composition, which have been explained by 'Maxwell Wagner Model'. The high dielectric constant and ac conductivity were observed of PANI@CFs than PANI. Moreover, PANI@CF 1:2 exhibited the promising photocatalytic activity for the photo-decoloration of the methyl orange (MO) dye under UV light irradiation. Results also showed protection of photo-decoloration of the MO dye by the disodium ethylenediaminetetraacetate dehydrate (EDTA-Na2; C10H14N2Na2O8·2H2O) (hole scavenger) and tert-butyl alcohol (C4H10O) (radical scavenger) clearly suggested the implication of reactive oxygen species (ROS) in the photocatalytic activity of PANI@CF 1:2. It is encouraging to conclude that PANI@CF bears the potential of its applications in photocatalysis.