Ibuprofen contamination from water sources has been increasingly alarming due to its environmentally accumulative retention; however, the strategies for ibuprofen-containing water treatment are still an enormous challenge. Herein, we described the utilization of metal-organic frameworks MIL-53(Fe) (MIL = Materials of Institute Lavoisier) for the adsorption of ibuprofen in synthetic solution. Firstly, the MIL-53(Fe) was solvothemally synthesized and then characterized using the X-ray diffraction and Fourier-transform infrared spectroscopy techniques. The optimization of ibuprofen adsorption over MIL-53(Fe) was performed with three independent variables including ibuprofen concentration (1.6–18.4 mg/L), adsorbent dosage (0.16–1.84 g/L), and pH (2.6–9.4) according to the experimental design from response surface methodology. Under the optimized conditions, more than 80% of ibuprofen could be eliminated from water, indicating the promising potential of the MIL-53(Fe) material for treatment of this drug. Kinetic and isotherm models also were used to elucidate the chemisorption and monolayer behavior mechanisms of ibuprofen over MIL-53(Fe).
The phonon-assisted cyclotron-resonance (PACR) effect due to the one-photon (1P) and two-photon (2P) absorption processes in a quantum well (QW) with the Pöschl-Teller (PT) potential is studied. The magneto-optical absorption coefficient as functions of photon energy for different QW-parameters, magnetic fields, and temperatures is presented. The calculations are done for four different possible cases: both 1P- and 2P-processes as well as both phonon emission and absorption processes. The numerical results for a GaAs, InAs, InSb, and GaSb PT-QW show that the PACR peaks are blueshifted with and magnetic field, redshifted with QW-length, but remained unchanged with temperature. Peak intensities are found to increase with and magnetic field and decrease with QW-length but have a complex dependency on the temperature. The full-width at half-maximum is found to increase with , magnetic field, and temperature but found to decrease with QW-length. The phonon emission process is always dominant in comparison with absorption. The 2P-process is comparable with the 1P-process and should be taken into account when studying the PACR in QWs.
12 February 2019 in Journal of Electronic Materials
In the present work, we consider systematically the electronic and optical properties of two-dimensional monolayer germanium monosulfide (GeS) under uniaxial strains along armchair (AC-strain) and zigzag (ZZ-strain) directions. Our calculations show that, at the equilibrium state, the monolayer GeS is a semiconductor with an indirect band gap of 1.82 eV. While monolayer GeS is still an indirect band gap semiconductor under ZZ-strain, an indirect–direct energy gap transition can be found in the monolayer GeS when the AC-strain is applied. The optical spectra of the monolayer GeS have strong anisotropy in the investigated energy range from 0 eV to 8 eV. Based on optical properties, we believe that the monolayer GeS is a potential candidate for applications in energy conversion and optoelectronic technologies.