02127nas a2200169 4500008004100000022001400041245015200055210006900207260000900276300001600285490000700301520146600308100001801774700001901792700001901811856012701830 2023 eng d a0743-746300aFerroelectric polarization and iron substitution synergistically boost electrocatalytic oxygen evolution reaction in bismuth oxychloride nanosheets0 aFerroelectric polarization and iron substitution synergistically cAUG  a11414-114250 v393 a

Ferroelectric materials have gained significant interestin variouskinds of water splitting, but the study of ferroelectric materialsfor electrocatalytic water splitting is in its infancy. Ferroelectricmaterials have spontaneous polarization below their Curie temperaturedue to dipolar alignment, which results in surface charges. In 2Dferroelectric materials, spontaneous polarization depends on thickness.Herein, we report that thickness-dependent ferroelectric polarizationin 2D nanosheets can also accelerate the oxygen evolution reaction(OER) along with the tailored active surface area of exposed crystallinefacets, which improves the electrocatalytic activity relatively. Iron-substitutedBiOCl nanosheets of varying thickness are fabricated by varying thepH using a facile coprecipitation method. The substituted iron enhancespolarization and electrochemical active sites on the surface. Thefindings in this study show that the exposed (001) facet and higherthickness of the nanosheets have high ferroelectric polarization and,in turn, superior electrocatalytic activity and remarkable stability,requiring low overpotentials (348 mV and 270 mV at 100 mA/cm(2) and 10 mA/cm(2)) in alkaline (1.0 M KOH) electrolyte. Asthe thickness of the nanosheets is decreased from 140 to 34 nm, theelectrocatalytic performance of iron-substituted BiOCl nanosheetsstarts to reduce due to the lower Coulomb-Coulomb interactionand the increasing depolarization.

1 aSingh, Dinesh1 aJoshi, Bhavana1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/ferroelectric-polarization-and-iron-substitution-synergistically-boost-electrocatalytic01504nas a2200157 4500008004100000022001400041245016300055210006900218260000800287300001600295490000700311520086500318100001801183700001901201856012601220 2023 eng d a0743-746300aScalable synthesis of dodecanethiol-capped bismuth nanoparticles by a solvent-free solid-state grinding method for reduction of 4-nitrophenol to 4-aminophenol0 aScalable synthesis of dodecanethiolcapped bismuth nanoparticles  cAug a11888-118970 v393 a

Thiol-capped metal nanoparticles have two constituents:an inorganicmetal and an organic molecule as a shell. Both characters are inbuiltin the structure of the metal thiolate. Herein, we have investigatedbismuth dodecanethiolate as a precursor for the synthesis of dodecanethiol-cappedbismuth nanoparticles (Bi NPs) by a solid-state grinding method. Byusing sodium borohydride and bismuth dodecanethiolate, crystallinebismuth nanoparticles are synthesized in a solvent-free environmentat room temperature (24 & PLUSMN; 4 & DEG;C). Bi NPs are tested for catalyticactivity by reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP)with an excess of NaBH4. Dodecanethiol-capped bismuth nanoparticlesexhibit an efficient reduction of 4-NP to 4-AP within 12 min. Additionally,these nanoparticles remain catalytically active for up to three cycles.

1 aSingh, Dinesh1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/scalable-synthesis-dodecanethiol-capped-bismuth-nanoparticles-solvent-free-solid-state02101nas a2200157 4500008004100000022001400041245017600055210006900231260000900300300001400309490000700323520144700330100001801777700001901795856012901814 2024 eng d a1144-054600aIn situ synthesis of metal (Bi0)-semiconductor [BiOX (X = Cl, Br, and I)] nanocomposites as a highly effective catalyst for the reduction of 4-nitrophenol to 4-aminophenol0 aIn situ synthesis of metal Bi0semiconductor BiOX X Cl Br and I n cMAY  a9840-98550 v483 a

The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) has been efficiently catalyzed by in situ generated Bi-0-BiOX (X = Cl, Br, I) nanocomposites in the presence of sodium borohydride (NaBH4). The hierarchical 3D arrays of precursors (BiOCl, BiOBr, and BiOI) have been synthesized by a facile co-precipitation method at ambient temperature. The metallic Bi-0 is generated in situ by partial reduction of the Bi3+ ions in BiOX (X = Cl, Br, and I) mediated by NaBH4 during the conversion of 4-NP to 4-AP. In situ generated Bi-0-BiOX shows better catalytic activity than Bi-0-BiOX composite formed by mixing individually synthesized metallic Bi-0 particles with semiconducting BiOX nanoparticles. The Bi-0-BiOI nanocomposite demonstrated higher catalytic activity (k(app) = 0.529 min(-1)) compared to Bi-0-BiOCl (k(app) = 0.095 min(-1)) and Bi-0-BiOBr (k(app) = 0.098 min(-1)) due to its efficient conversion into metallic Bi-0. The approximate percentage composition of in situ generated metallic Bi-0 on the surface of BiOCl, BiOBr, and BiOI is nearly 10, 17, and 25%, respectively. Further, the reduction of 4-NP has been completed within 24, 22, and 6 minutes by in situ generated Bi-0-BiOCl, Bi-0-BiOBr, and Bi-0-BiOI nanocomposites from BiOCl, BiOBr, and BiOI, respectively. Extensive studies have been conducted to generate a better understanding of the actual catalytic sites present on the surface of the catalysts.

1 aSingh, Dinesh1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/situ-synthesis-metal-bi0-semiconductor-biox-x-cl-br-and-i-nanocomposites-highly-effective02060nas a2200193 4500008004100000022001400041245013600055210006900191260000800260490000700268520132600275653002501601653002401626653003301650100001801683700002101701700001901722856012501741 2025 eng d a1434-194800aAn in-depth study of the Fe-Se system at the nanoscale reveals remarkable results on the electrocatalytic oxygen evolution reaction0 aindepth study of the FeSe system at the nanoscale reveals remark cMAR0 v283 a

A catalyst for an electrocatalytic oxygen evolution reaction (OER) is a key component of the large-scale storage of renewable energy through the conversion of water into oxygen and hydrogen. Iron-based selenide materials are currently being considered as potential options for electrocatalytic oxygen evolution reaction (OER) because of their, widespread availability, low cost, and outstanding performance. In this study, we employed a thermal decomposition method to synthesize all stable phases of the Fe-Se system, including Fe7Se8, Fe3Se4, FeSe2, and FeSe. Additionally, we slurry-coated these phases onto a three-dimensional (3D) nickel foam substrate. The prepared 3D electrodes of Fe7Se8, Fe3Se4, FeSe2, and FeSe exhibit remarkably low overpotentials of 270, 276, 299, and 289 mV at a current density of 50 mA/cm2 for OER. In addition, the catalytic activity for OER is also tested on glassy carbon electrodes to compare its performance with the Ni-foam 3D substrate. The Fe7Se8 phase in the Fe-Se system exhibits the highest catalytic activity towards OER on both substrates due to variations in the Fe2+/Fe3+ ratio and the presence of Fe vacancies (cation vacancies) within the crystal lattice. Moreover, a faradaic efficiency of 98 % was exhibited by Fe7Se8 for the oxygen evolution reaction (OER).

10aIron selenide system10aOER electrocatalyst10aThermal decomposition method1 aSingh, Dinesh1 aGhalawat, Monika1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/depth-study-fe-se-system-nanoscale-reveals-remarkable-results-electrocatalytic-oxygen01469nas a2200229 4500008004100000022001400041245007600055210006900131260000900200300001100209490000900220520073600229653001100965653003700976653002701013653002201040653001501062100002001077700001801097700001901115856010501134 2025 eng d a0925-838800aStudy of magnetism and electrocatalytic properties in perovskite DyCrO30 aStudy of magnetism and electrocatalytic properties in perovskite cFEB  a1789340 v10163 a

Uniformly sized perovskite DyCrO3 was synthesized by facile hydrothermal method. Complex interdependence of various parameters such as - pH, crystal growth duration, reaction temperature, precursor, and capping molecules on crystal growth was extensively investigated. The effect of synthesis parameters on the magnetic properties of hydrothermally synthesized DyCrO3 was compared with high-temperature synthesized DyCrO3. DyCrO3's potential for electrocatalytic water splitting in an alkaline medium (1.0 M KOH) was also evaluated. It demonstrates an overpotential of 280 mV for oxygen evolution reaction (OER) and 210 mV for hydrogen evolution reaction (HER). Further, it exhibits promising stability for OER and HER.

10aDyCrO310aElectrocatalytic water splitting10aHydrothermal synthesis10amagnetic property10aperovskite1 aUghade, Supriya1 aSingh, Dinesh1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/study-magnetism-and-electrocatalytic-properties-perovskite-dycro302568nas a2200157 4500008004100000022001400041245010700055210007300162260000800235300001400243490000800257520196300265100001802228700001902246856014502265 2026 eng d a1932-744700aTuning the electric dipole transitions (5D0 → 7F2 and 5D0 → 7F4) in thin Eu-doped BiOCl nanosheets0 aTuning the electric dipole transitions 5D0 → 7F2 and 5D0 → 7F4 i cMAR a3504-35170 v1303 a

The polarization and depolarization of layered ferroelectric materials can be tuned by altering the thickness of nanosheets, apart from controlling inter/intralayer distances, doping of ions, the surrounding dielectric environment, etc. In two-dimensional, single-crystalline ferroelectric nanosheets, the reduction in the thickness facilitates the internal electric field (IEF), which leads to enhanced depolarization. BiOCl is a layered ferroelectric material with repeating layers of [Bi2O2](2+), which exhibit anisotropy. However, the depolarization and polarization of BiOCl are significantly influenced by the thicknesses of its nanosheets. Herein, 1-dodecanethiol-capped europium (Eu3+)-doped BiOCl thin nanosheets resembling a two-dimensional structure have been synthesized using the solid-state grinding method at ambient temperature. As a result of the depolarization effect, the strength of the electric dipole transitions D-5(0) -> F-7(2) and D-5(0) -> F-7(4) increases in the Eu-doped BiOCl nanosheets. However, thiol capping helps in synthesizing uniform 2D nanosheets with reduced vertical dimensions (thickness near 15-30 nm). It is observed that all of the prepared samples with varying Eu ion concentrations show uniform nanosheet-like morphology, as confirmed by electron microscopy (FESEM and HRTEM). As the concentration of Eu ions increases in the BiOCl host lattice, the intensity of electric dipole transitions also increases (until 9 mol %). Fourier transform infrared spectroscopy (FT-IR) reveals the coating of 1-dodecanthiol on the Eu-doped BiOCl molecule. Furthermore, the Eu-doped BiOCl samples showed prominent far-red emission at 700 nm, corresponding to the D-5(0) -> F-7(4) transition. Moreover, this work emphasizes the synthesis of Eu-doped phosphor at an ambient temperature of 24 +/- 2 degrees C and generates a deeper understanding of the abnormal electric dipole (D-5(0) -> F-7(4)) transition.

1 aSingh, Dinesh1 aPoddar, Pankaj uhttps://library.ncl.res.in/content/tuning-electric-dipole-transitions-5d0-%E2%86%92-7f2-and-5d0-%E2%86%92-7f4-thin-eu-doped-biocl-nanosheets