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Novel few-layer MoS2 nanosheets incorporated α-Fe2O3/ZnO photocatalyst nanocomposite is reported with high dye degradation and hydrogen evolution ability under solar illumination.

Bangladesh is one in all the foremost climate vulnerable countries of the world. In recent years, climate change studies over the country get plenty of attention by the researchers and policy makers. A substantial quantity of global climate change studies over the country use climate models to estimate future projections and uncertainties. Maximum temperature, precipitation and their potential future changes are evaluated in an ensemble of the 5th Phase Coupled Model Inter-comparison Project (CMIP5) within the Intergovernmental Panel on Climate Change (IPCC) diagnostic exercise for the Fifth Assessment Report (AR5) and the available historical data collected by the Bangladesh Meteorological Department (BMD) during the period 1981-2008 in the north-western region of Bangladesh and also the comparison between these two values. It has been found that average maximum temperature shows a positive trend of increase at a rate of 0.29˚C and 5.3˚C per century respectively, for BMD data and MPI-ESM-LR (CMIP5) model data. But the rainfall is decreasing at a rate of 8.8 mm and 40.1 mm per century respectively for BMD data and MPI-ESM-LR (CMIP5) model data. It is seen that July was the maximum monsoon rainfall month and January was the lowest rainfall month. The peak frequency is slightly smaller than 12 months, which indicates that the major events are occurring before ending a year compared to the previous year. According to MPI-ESM-LR (CMIP5) model data, future normal temperature on north-western region will be increased at a rate of 1.62˚C during the period 2040-2100.

Here, the first-principles predictions on the structural stability, magnetic behavior and electronic structure of B-site ordered double perovskite Nd$_2$CrFeO$_6$ have been reported. Initially, the ground state of the parent single...

We have synthesized Gd2FeCrO6 (GFCO) double perovskite which crystallized in monoclinic structure with P21/n space group. The UV-visible and photoluminescence spectroscopic analyses confirmed its direct band gap semiconducting nature. Here, by employing experimentally obtained structural parameters in first-principles calculation, we have reported the spin-polarized electronic band structure, charge carrier effective masses, density of states, electronic charge density distribution and optical absorption property of this newly synthesized GFCO double perovskite. Moreover, the effects of on-site d-d Coulomb interaction energy (U eff ) on the electronic and optical properties were investigated by applying a range of Hubbard U eff parameter from 0 to 6 eV to the Fe-3d and Cr-3d orbitals within the generalized gradient approximation (GGA) and GGA+U methods. Notably, when we applied U eff in the range of 1 to 5 eV, both the up-spin and down-spin band structures were observed to be direct. The charge carrier effective masses were also found to enhance gradually from U eff = 1 eV to 5 eV, however, these values were anomalous for U eff = 0 and 6 eV. These results suggest that U eff should be limited within the range of 1 to 5 eV to calculate the structural, electronic and optical properties of GFCO double perovskite. Finally we observed that considering U eff = 3 eV, the theoretically calculated optical band gap ∼1.99 eV matched well with the experimentally obtained value ∼2.0 eV. The outcomes of our finding imply that the U eff value of 3 eV most accurately localized the Fe-3d and Cr-3d orbitals of GFCO keeping the effect of self-interaction error from the other orbitals almost negligible. Therefore, we may recommend U eff = 3 eV for first-principles calculation of the electronic and optical properties of GFCO double perovskite that might have potential in photocatalytic and related solar energy applications.