Contemporary innovations in two-dimensional transition metal dichalcogenide-based P-N junctions for optoelectronics.

Two-dimensional transition metal dichalcogenides (2D-TMDCs) with various physical characteristics have attracted significant interest from the scientific and industrial worlds in the years following Moore's law. The p-n junction is one of the earliest electrical components to be utilized in electronics and optoelectronics, and modern research on 2D materials has renewed interest in it. In this regard, device preparation and application have evolved substantially in this decade. 2D TMDCs provide unprecedented flexibility in the construction of innovative p-n junction device designs, which is not achievable with traditional bulk semiconductors. It has been investigated using 2D TMDCs for various junctions, including homojunctions, heterojunctions, P-I-N junctions, and broken gap junctions. To achieve high-performance p-n junctions, several issues still need to be resolved, such as developing 2D TMDCs of superior quality, raising the rectification ratio and quantum efficiency, and successfully separating the photogenerated electron-hole pairs, among other things. This review comprehensively details the various 2D-based p-n junction geometries investigated with an emphasis on 2D junctions. We investigated the 2D p-n junctions utilized in current rectifiers and photodetectors. To make a comparison of various devices easier, important optoelectronic and electronic features are presented. We thoroughly assessed the review's prospects and challenges for this emerging field of study. This study will serve as a roadmap for more real-world photodetection technology applications.

Recent advancement in quantum dot-based materials for energy storage applications: a review.

The need for energy storage and conversion is growing as a result of the worsening consequences of climate change and the depletion of fossil fuels. Energy conversion and storage requirements are rising as a result of environmental problems including global warming and the depletion of fossil fuels. The key to resolving the energy crisis is anticipated to be the quick growth of sustainable energy sources including solar energy, wind energy, and hydrogen energy. In this review, we have focused on discussing various quantum dots (QDs) and polymers or nanocomposites used for SCs and have provided examples of each type's performance. Effective QD use has really led to increased performance efficiency in SCs. The use of quantum dots in energy storage devices, batteries, and various quantum dots synthesis have all been emphasized in a number of great literature articles. In this review, we have homed in on the electrode materials based on quantum dots and their composites for storage and quantum dot based flexible devices that have been published up to this point.

Cation Incorporation and Synergistic Effects on the Characteristics of Sulfur-Doped Manganese Ferrites S@Mn(Fe2O4) Nanoparticles for Boosted Sunlight-Driven Photocatalysis.

In the present work, sulfur-doped manganese ferrites S@Mn(Fe2O4) nanoparticles were prepared by using the sol-gel and citrate method. The concentration of sulfur varied from 1 to 7% by adding Na2S. The samples were characterized by performing Fourier Transformed Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Ultraviolet-Visible spectroscopy (UV-Visible). The synthesized sulfur-doped manganese ferrites were applied to evaluate the photocatalytic degradation of the dyes. Further, the degradation studies revealed that the nanoparticles successfully degraded the methylene blue dye by adding a 0.006 g dose under the sunlight. The sulfur-doped manganese ferrite nanoparticles containing 3% sulfur completely degraded the dye in 2 h and 15 min in aqueous medium. Thus, the ferrite nanoparticles were found to be promising photocatalyst materials and could be employed for the degradation of other dyes in the future.

Eucalyptus Concoction Mediated Synthesis of Gold Nanoparticles and Its Bioactive Role Explored via Antimicrobial and Cytotoxic Studies.

Biosynthesis of nanoparticles has now become a novel trend in addressing some of the environmental issues by adopting eco-friendly approaches in manoeuvring nanoparticles for various applications. Plants and micro-organisms have been the potential sources of the biological mode of synthesizing nanoparticles as part of their bioremediation process. This principle has been harnessed for synthesizing nanoparticles either extra or intracellularly. In this line of phyto-mediated synthesis, eucalyptus buds have been used for synthesizing gold nanoparticles (Au NPs) under optimized laboratory conditions. The UV-visible spectrum of the Au NPs showed typical surface plasmon resonance at 550 nm (λmax) with a crystalline phase measuring <100 nm in size and monodispersed as revealed from XRD, FESEM, and AFM analyses. The biological role of phytochemical concoction in reducing and stabilizing the Au NPs was clearly identified from FT-IR studies. The antimicrobial effect of the Au NPs against clinically important pathogens viz. Staphylococcus sp., Pseudomonas sp., Bacillus sp. and E. coli determined using the disk diffusion method showed no significant antibacterial effect at all concentrations. Cytotoxicity studies were carried using Vero and HEp-2 cell lines and the 50% inhibition concentration (IC50) was determined to be 1.25 mg and 0.625 mg/mL respectively. Au NPs with potential antimicrobial and anti-proliferative effects could found profound implications in the field of nanomedicine once the toxicity in vivo has been investigated.

Effect of Nickel Doping on the Properties of Hydroxyapatite Nanoparticles.

Herein, we studied the effect of nickel (Ni) doping on the properties of hydroxyapatite (HAp) nanoparticles synthesized by facile ultrasonication assisted wet chemical synthesis process. Various doping concentrations of nickel, i.e., 0.01 M, 0.05 M and 0.10 M, were used to dope into hydroxyapatite nanoparticles. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) pattern, scanning electron spectroscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, UV-Visible spectroscopy and Raman-scattering spectroscopy. The detailed structural characterizations confirmed that the crystallite sizes of the Ni-doped hydroxyapatite nanoparticles were reduced up to 53% compared to pure hydroxyapatite upon the doping of different concentrations of Ni ions. The agglomeration in the nanoparticles was also reduced by increasing the doping concentration of Ni ions. The XRD studies revealed that the average crystallite size of the synthesized Ni-doped HAp was decreased with increasing the concentration of Ni2+ ion doping and this observation was well-consistent with the SEM results. The FTIR and Raman studies well-confirmed the formation of pure HAp and Ni-doped HAp. Further, doping with Ni creates a new level of energy between the conductive band and the valence band and hence with increasing the concentration of Ni2+, the intensity in the UV-vis spectra was enhanced.

Sunlight-Driven Photocatalytic Degradation of Methyl Orange Based on Bismuth Ferrite (BiFeO3) Heterostructures Composed of Interconnected Nanosheets.

Herein, we report the facile microwave-assisted synthesis, characterization and photocatalytic degradation applications of Bismuth ferrite heterostructures composed of interconnected nanosheets (BHNs). The synthesized materials were subjected to several analytical studies such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy in order to examine the morphological, structural, optical and photo catalytic properties. The structural and morphological characterizations confirmed the rhombohedral perovskite crystal structure and the formation of heterostructures composed of interconnected nanosheets for the synthesized material. The compositional characterization revealed that the synthesized material is bismuth ferrite with high purity. The BHNs were further used as efficient photocatalyst for the photocatalytic degradation of highly hazardous pollutant methyl orange under sunlight irradiation. The sunlight driven photocatalytic experiments revealed ~86% photodegradation of methyl orange dye in 150 min. The presented work revealed that the synthesized BHNs are excellent material for the photocatalytic degradation of various organic contaminants and hazardous pollutants.

Visible-Light Driven Photocatalytic Degradation of Eosin Yellow (EY) Dye Based on NiO-WO3 Nanoparticles.

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO3 nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The synthesized NiO-WO3 nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of Eosin yellow (EY) dye. Interestingly, the synthesized photocatalytic exhibited a significant visible-light driven photocatalytic degradation of Eosin yellow (EY) dye. Under optimized conditions (pH = 5, catalyst dosage = 3 µM and initial dye concentration= 1.0 g/L), the obtained photo degradation of EY dye was above 95% in 180 min under visible light irradiation. Remarkably, reusability of the prepared photocatalyst was also observed and the photo-degradation reactions follow the pseudo-first-order model.

Synthesis of Iron Oxide@Pt Core-Shell Nanoparticles for Reductive Conversion of Cr(VI) to Cr(III) and Antibacterial Studies.

Herein, we report the facile synthesis of Iron oxide@Pt core-shell nanoparticles (NPs) by facile two step synthesis process. The first step follows the growth of iron oxide nanoparticle by thermal decomposition process while the second step deals with the formation of iron oxide@Pt core-shell nanoparticles by the chemical reduction method. The synthesized core-shell nanoparticles were characterized by several techniques and used for the catalytic reductive translation of Cr(VI) to Cr(III) in the presence of formic acid by a UV-vis spectrophotometer. The UV photo-spectrometer analysis confirmed the conversion efficiency from 12% to as high as 98.8% at the end of 30 minutes. Thus, the presence of Iron oxide @Pt core-shell nanoparticles (NPs) can be effectively used as a catalyst for the reducion of Cr(VI) to Cr(III) ions. Additionally, antibacterial studies were performed for the prepared core-shell nanoparticles against two bacterial strains, i.e., gram (+ve) Staphylococcus Aureus (S. Aureus) and gram (-ve) Escherichia Coli (E. Coli).

Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications.

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 µA mM-1 cm-2 with a low detection limit of 1.05 mM in a short response time of 10 s.