针对溴酸盐(BrO-3)污染,本研究以三聚氰胺为前驱体制备石墨相氮化碳(g-C3N4)为自由基诱导催化材料.通过XRD、TEM、UV/Vis-DRS对其物相组成和光催化性能进行表征发现,制备的层状g-C3N4有稳定片层结构及可见光响应的禁带宽度(~2.70 e V)....针对溴酸盐(BrO-3)污染,本研究以三聚氰胺为前驱体制备石墨相氮化碳(g-C3N4)为自由基诱导催化材料.通过XRD、TEM、UV/Vis-DRS对其物相组成和光催化性能进行表征发现,制备的层状g-C3N4有稳定片层结构及可见光响应的禁带宽度(~2.70 e V).可见光照射下,g-C3N4表面产生的光生载流子不能直接还原溴酸盐.然而,若有有机小分子(如甲醇)存在,光催化还原效率迅速增大.通过原位电子顺磁共振谱(EPR)及对材料表面的光电化学测试分析,我们探索了该体系的光催化还原Br O-3的机制.结果表明,g-C3N4带隙较窄其空穴氧化能力较弱,在光催化过程中空穴只能将甲醇分子转化为CH3O·自由基,因而甲醇分子的存在提升了光生载流子的分离效率,加剧了自由基的累积.该自由基具有较高的还原活性,可迅速将水相中的溴酸根还原至溴离子.展开更多
In this paper, a novel polymeric complex [MnNa（Salicylate）2（CH3OH）（H2O）]n·0.5nH2O was obtained and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. The titled complex is...In this paper, a novel polymeric complex [MnNa（Salicylate）2（CH3OH）（H2O）]n·0.5nH2O was obtained and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. The titled complex is crystallized in triclinic system, space group P1 with a=0.763 82（15） nm, b= 1.037 1（2） nm, c=1.290 9（3） nm, α= 103.59（3）°, β=104.65（3）°, γ=109.50（3）°, V=0.873 6（3） nm 3, Z=2, Dc=1.556 Mg/m 3, Mr=409.20, μ=0.823 mm -1, F（000）=418, R=0.0614, wR= 0.147 6. The activity in catalyzing the superoxygen anionic free radical dismutation was determinated.展开更多
Adsorption of CH3O at four sites （top, bridge, hcp, fcc） on Au（111） surface has been investigated by density functional theory method at the generalized gradient approximation level. We have performed calculations...Adsorption of CH3O at four sites （top, bridge, hcp, fcc） on Au（111） surface has been investigated by density functional theory method at the generalized gradient approximation level. We have performed calculations on adsorption energies, structures, Mulliken charges and vibrational frequencies of CH3O on Au（111） surface with full-geometry optimization. The predicted results are compared with the available experimental observation. The calculated CH3O adsorption structure and stretching vibrational frequencies agree well with experimental ones, and precise determinations of adsorption sites are carded out. The most favorite adsorption on Au（111） occurs at the bridge site, and O-C axis is tilted to the surface. However, on hollow sites （hcp, fcc） the species is adsorbed in an upright geometry （pseudo-C3v local symmetry）.展开更多
文摘针对溴酸盐(BrO-3)污染,本研究以三聚氰胺为前驱体制备石墨相氮化碳(g-C3N4)为自由基诱导催化材料.通过XRD、TEM、UV/Vis-DRS对其物相组成和光催化性能进行表征发现,制备的层状g-C3N4有稳定片层结构及可见光响应的禁带宽度(~2.70 e V).可见光照射下,g-C3N4表面产生的光生载流子不能直接还原溴酸盐.然而,若有有机小分子(如甲醇)存在,光催化还原效率迅速增大.通过原位电子顺磁共振谱(EPR)及对材料表面的光电化学测试分析,我们探索了该体系的光催化还原Br O-3的机制.结果表明,g-C3N4带隙较窄其空穴氧化能力较弱,在光催化过程中空穴只能将甲醇分子转化为CH3O·自由基,因而甲醇分子的存在提升了光生载流子的分离效率,加剧了自由基的累积.该自由基具有较高的还原活性,可迅速将水相中的溴酸根还原至溴离子.
文摘In this paper, a novel polymeric complex [MnNa（Salicylate）2（CH3OH）（H2O）]n·0.5nH2O was obtained and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. The titled complex is crystallized in triclinic system, space group P1 with a=0.763 82（15） nm, b= 1.037 1（2） nm, c=1.290 9（3） nm, α= 103.59（3）°, β=104.65（3）°, γ=109.50（3）°, V=0.873 6（3） nm 3, Z=2, Dc=1.556 Mg/m 3, Mr=409.20, μ=0.823 mm -1, F（000）=418, R=0.0614, wR= 0.147 6. The activity in catalyzing the superoxygen anionic free radical dismutation was determinated.
文摘Adsorption of CH3O at four sites （top, bridge, hcp, fcc） on Au（111） surface has been investigated by density functional theory method at the generalized gradient approximation level. We have performed calculations on adsorption energies, structures, Mulliken charges and vibrational frequencies of CH3O on Au（111） surface with full-geometry optimization. The predicted results are compared with the available experimental observation. The calculated CH3O adsorption structure and stretching vibrational frequencies agree well with experimental ones, and precise determinations of adsorption sites are carded out. The most favorite adsorption on Au（111） occurs at the bridge site, and O-C axis is tilted to the surface. However, on hollow sites （hcp, fcc） the species is adsorbed in an upright geometry （pseudo-C3v local symmetry）.
