Solvent extraction experiments were conducted from acidic solutions containing germanium(IV) and other metal ions, such as Ga 3+ , Fe 3+ , Zn 2+ and Fe 2+ in hydrometallurgical process of zinc. The purpose of this wor...Solvent extraction experiments were conducted from acidic solutions containing germanium(IV) and other metal ions, such as Ga 3+ , Fe 3+ , Zn 2+ and Fe 2+ in hydrometallurgical process of zinc. The purpose of this work was to enhance the efficiency of the extraction and stripping processes and the selectivity of germanium and other metals, while making the method as simple as possible. Germanium was recovered from sulfuric acid, using di-(2-ethylhexyl) phosphoric acid (P204) as an extractant, tributyl phosphate (TBP) as modifier diluted in sulfonate kerosene and stripped by NaOH aqueous solution. Extraction studies were carried out under different acid concentrations and solvent concentrations, and optimized conditions were determined. The numbers of stages required for extraction and stripping of metal ions were determined from the McCabe-Thiele plot. The results show that the extracting and stripping efficiencies are 94.3% and 100%, respectively, through two-stage extraction and two-stage strip. Moreover, the synergistic effect of TBP on the system P204/kerosense/Ge 4+ is revealed with respect to the extraction of germanium.展开更多
Germanium diselenide(GeSe_(2))is a promising candidate for electronic devices because of its unique crystal structure and optoelectronic properties.However,the evolution of lattice and electronic structure ofβ-GeSe_(...Germanium diselenide(GeSe_(2))is a promising candidate for electronic devices because of its unique crystal structure and optoelectronic properties.However,the evolution of lattice and electronic structure ofβ-GeSe_(2)at high pressure is still uncertain.Here we prepared high-qualityβ-GeSe_(2)single crystals by chemical vapor transfer(CVT)technique and performed systematic experimental studies on the evolution of lattice structure and bandgap ofβ-GeSe_(2)under pressure.High-precision high-pressure ultra low frequency(ULF)Raman scattering and synchrotron angle-dispersive x-ray diffraction(ADXRD)measurements support that no structural phase transition exists under high pressure up to 13.80 GPa,but the structure ofβ-GeSe_(2)turns into a disordered state near 6.91 GPa and gradually becomes amorphous forming an irreversibly amorphous crystal at 13.80 GPa.Two Raman modes keep softening abnormally upon pressure.The bandgap ofβ-GeSe_(2)reduced linearly from 2.59 eV to 1.65 eV under pressure with a detectable narrowing of 36.5%,and the sample under pressure performs the piezochromism phenomenon.The bandgap after decompression is smaller than that in the atmospheric pressure environment,which is caused by incomplete recrystallization.These results enrich the insight into the structural and optical properties ofβ-GeSe_(2)and demonstrate the potential of pressure in modulating the material properties of two-dimensional(2D)Ge-based binary material.展开更多
基金Project(50774094)supported by the National Natural Science Foundation of China
文摘Solvent extraction experiments were conducted from acidic solutions containing germanium(IV) and other metal ions, such as Ga 3+ , Fe 3+ , Zn 2+ and Fe 2+ in hydrometallurgical process of zinc. The purpose of this work was to enhance the efficiency of the extraction and stripping processes and the selectivity of germanium and other metals, while making the method as simple as possible. Germanium was recovered from sulfuric acid, using di-(2-ethylhexyl) phosphoric acid (P204) as an extractant, tributyl phosphate (TBP) as modifier diluted in sulfonate kerosene and stripped by NaOH aqueous solution. Extraction studies were carried out under different acid concentrations and solvent concentrations, and optimized conditions were determined. The numbers of stages required for extraction and stripping of metal ions were determined from the McCabe-Thiele plot. The results show that the extracting and stripping efficiencies are 94.3% and 100%, respectively, through two-stage extraction and two-stage strip. Moreover, the synergistic effect of TBP on the system P204/kerosense/Ge 4+ is revealed with respect to the extraction of germanium.
基金the National Natural Science Foundation of China(Grant Nos.12004339,11874328,11904322,61804047,22071221,and 21905252)China Postdoctoral Science Foundation(Grant Nos.2018M640679 and 2019T120629)the Zhongyuan Academician Foundation(Grant No.ZYQR201810163)。
文摘Germanium diselenide(GeSe_(2))is a promising candidate for electronic devices because of its unique crystal structure and optoelectronic properties.However,the evolution of lattice and electronic structure ofβ-GeSe_(2)at high pressure is still uncertain.Here we prepared high-qualityβ-GeSe_(2)single crystals by chemical vapor transfer(CVT)technique and performed systematic experimental studies on the evolution of lattice structure and bandgap ofβ-GeSe_(2)under pressure.High-precision high-pressure ultra low frequency(ULF)Raman scattering and synchrotron angle-dispersive x-ray diffraction(ADXRD)measurements support that no structural phase transition exists under high pressure up to 13.80 GPa,but the structure ofβ-GeSe_(2)turns into a disordered state near 6.91 GPa and gradually becomes amorphous forming an irreversibly amorphous crystal at 13.80 GPa.Two Raman modes keep softening abnormally upon pressure.The bandgap ofβ-GeSe_(2)reduced linearly from 2.59 eV to 1.65 eV under pressure with a detectable narrowing of 36.5%,and the sample under pressure performs the piezochromism phenomenon.The bandgap after decompression is smaller than that in the atmospheric pressure environment,which is caused by incomplete recrystallization.These results enrich the insight into the structural and optical properties ofβ-GeSe_(2)and demonstrate the potential of pressure in modulating the material properties of two-dimensional(2D)Ge-based binary material.
