Synthesis of Bi₂Fe₄O₉Crystalline Ceramic as Extremely Capable Photocatalyst via Proficient Chemical Route

Bi2Fe4O9 crystalline ceramic was successfully synthesized through a soft chemical route at lower sintering temperature for analysis of photocatalytic behavior with respect to adsorption of Congo Red (CR) in the presence of UV-VIS irradiation. The single-phase formation of Bi2Fe4O9 ceramic was confirmed by powder X-ray diffraction studies and particle size observed by TEM analysis was found to be 148 ± 5 nm which reveals the crystalline nature of the materials. Additionally, the photocatalytic activity of Bi2Fe4O9 ceramic was evaluated by the degradation of Congo Red in presence of visible light. The optical band gap (Eg) of the synthesized materials was found to be 1.8 eV. It exhibited greater photocatalytic activity than other synthesized materials like BiFeO3 as well as TiO2 due to a smaller band gap (1.8 eV). Furthermore, process variables such as pH.

Holocene Floral and Faunal Remains Revealed Concealed Neotectonic Disturbance (Saria Tal, Kumaun Himalaya, India)

Palynological and paleontological investigations supported by the radiocarbon dates of the lacustrine sediments of two profiles from the temperate lake Saria Tal, in Naini Tal District, Kumaun Himalaya, have revealed the presence of a concealed fold at the region. The profile from bore cores represents the upper part of the Late Holocene and the profile from exposed sections from the Middle Holocene to the over middle part of the Late Holocene. The data generated from different investigations have uniformly indicated that the former profile represents normal superposition, while the latter represents the reverse order. The contemporary pollen as well as molluscan zones of both profiles are situated at different elevations but consist of similar bioremains - indicating continuation of the same strata in two profiles. The presence of reverse order of superposition, continuation of the same strata in two profiles at different elevations, and the orientation of biozones, have indicated that the revealed folding is of syncline type. The present study has also given an idea about the origin of this lake.

Investigation of strong shock wave interactions with CeO2 ceramic

Strong shock wave interactions with ceramic material ceria(CeO_(2))in presence of O_(2)and N2 gases were investigated using free piston driven shock tube(FPST).FPST is used to heat the test gas to very high temperature of about 6800-7700 K(estimated)at pressure of about 6.8-7.2 MPa for short duration(2-4 ms)behind the reflected shock wave.Ceria is subjected to super heating and cooling at the rate of about 106 K/s.Characterization of CeO_(2)sample was done before and after exposure to shock heated test gases(O_(2)and N2).The surface composition,crystal structure,electronic structure and surface morphology of CeO_(2)ceramic were examined using X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectrometry,scanning electron microscopy(SEM)and high resolution transmission electron microscopy(HRTEM).Results obtained from the experimental investigations show that CeO_(2)can withstand high pressure accompanied by thermal shock without changing its crystal structure.Reducible CeO_(2)releases lattice oxygen making it possible to shift between reduced and oxidized states upon the interaction with shock heated gas.Due to such reaction mechanism,CeO_(2)ceramic undergoes nitrogen doping with decrease in lattice parameter.Investigations reveal that CeO_(2)retains its crystal structure during strong shock interaction,even at elevated pressure.