The graphene oxides （GOs） have attracted multidisciplinary study because of their special physicochemical properties. The high surface area and large amounts of oxygen-containing functional groups make GOs suitable ...The graphene oxides （GOs） have attracted multidisciplinary study because of their special physicochemical properties. The high surface area and large amounts of oxygen-containing functional groups make GOs suitable materials for the efficient elimination of heavy metal ions from aqueous solutions. Herein the sorption of Ni（Ⅱ） on GOs was studied using batch experi- ments, and the results showed that the sorption of Ni（Ⅱ） is strongly dependent on pH and ionic strength at pH〈8, and inde- pendent of ionic strength at pH〉8. The sorption of Ni（Ⅱ） is mainly dominated by outer-sphere surface complexation and ion exchange at low pH, and by inner-sphere surface complexation at high pH. The interaction of Ni（Ⅱ） with GOs was also inves- tigated by theoretical density functional theory （DFT） calculations, and the results show that the sorption of Ni（Ⅱ） on GOs is mainly attributed to the -COH and -COC groups and the DFT calculations show that Ni（Ⅱ） forms stable GO_Ni_triplet struc- ture with the binding energy of -39.44 kcal/mol, which is in good agreement with the batch sorption experimental results. The results are important for the application of GOs as adsorbents in the efficient removal of Ni（Ⅱ） from wastewater in environ- mental pollution cleanup.展开更多
In the above referenced publication[1],the Figure 5 and data in Table 1 are correct,but we ignored to present the final pH values of the system,which is very important to understand the properties.
To contribute to the understanding of Eu(Ⅲ)interaction properties on hydrous alumina particles in the absence and presence of fulvic acid(FA),the complexation properties of Eu(Ⅲ)with hydrous alumina,FA and FA-alumin...To contribute to the understanding of Eu(Ⅲ)interaction properties on hydrous alumina particles in the absence and presence of fulvic acid(FA),the complexation properties of Eu(Ⅲ)with hydrous alumina,FA and FA-alumina hybrids are studied by batch and time-resolved laser fluorescence spectroscopy(TRLFS)techniques.The continuous increase in the fluorescence lifetime of Eu-alumina and Eu-FA with increasing pH indicates that the complexation is accompanied by decreasing number of hydration water in the first coordination sphere of Eu(Ⅲ).Eu(Ⅲ)is adsorbed onto alumina particles as outer-sphere surface complexes of≡(Al-O)-Eu·(OH)·7H_2O and≡(Al-O)-Eu·6H_2O at low pH values,and as inner-sphere surface complexes as≡(Al-O)_2-Eu^+·4H_2O at high pH.In FA solution,Eu(Ⅲ)forms complexes with FA as(COO)_2Eu^+(H_2O)_x and the hydration water number in the first coordination sphere decreases with pH increasing.The formation of≡COO-Eu-(O-Al≡)·4H_2O is observed on FA-alumina hybrids,suggesting the formation of strong inner-sphere surface complexes in the presence of FA.The surface complexes are also characterized by their emission spectra[the ratio of emission intensities of^5D_0→~7F_1(λ=594nm)and^5D_0→~7F_2(λ=619nm)transitions]and their fluorescence lifetime.The findings is important to understand the contribution of FA in the complexation properties of Eu(Ⅲ)on FA-alumina hybrids that the clarification of the environmental behavior of humic substances is necessary to understand fully the behavior of Eu(Ⅲ),or its analogue trivalent lanthanide and actinide ions in natural environment.展开更多
基金supported by the Deanship of Scientific Research,King Abdulaziz University(41-130-36-Hi Ci)
文摘The graphene oxides （GOs） have attracted multidisciplinary study because of their special physicochemical properties. The high surface area and large amounts of oxygen-containing functional groups make GOs suitable materials for the efficient elimination of heavy metal ions from aqueous solutions. Herein the sorption of Ni（Ⅱ） on GOs was studied using batch experi- ments, and the results showed that the sorption of Ni（Ⅱ） is strongly dependent on pH and ionic strength at pH〈8, and inde- pendent of ionic strength at pH〉8. The sorption of Ni（Ⅱ） is mainly dominated by outer-sphere surface complexation and ion exchange at low pH, and by inner-sphere surface complexation at high pH. The interaction of Ni（Ⅱ） with GOs was also inves- tigated by theoretical density functional theory （DFT） calculations, and the results show that the sorption of Ni（Ⅱ） on GOs is mainly attributed to the -COH and -COC groups and the DFT calculations show that Ni（Ⅱ） forms stable GO_Ni_triplet struc- ture with the binding energy of -39.44 kcal/mol, which is in good agreement with the batch sorption experimental results. The results are important for the application of GOs as adsorbents in the efficient removal of Ni（Ⅱ） from wastewater in environ- mental pollution cleanup.
文摘In the above referenced publication[1],the Figure 5 and data in Table 1 are correct,but we ignored to present the final pH values of the system,which is very important to understand the properties.
基金Financial supports from the National Natural Science Foundation of China(21225730,91326202 and 21577032)the Fundamental Research Funds for the Central Universities(JB2015001)+1 种基金Kunlun scholarship of Qinghai province,the priority Academic program development of Jiangsu Higher Education Institutionsthe Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions are acknowledged
文摘To contribute to the understanding of Eu(Ⅲ)interaction properties on hydrous alumina particles in the absence and presence of fulvic acid(FA),the complexation properties of Eu(Ⅲ)with hydrous alumina,FA and FA-alumina hybrids are studied by batch and time-resolved laser fluorescence spectroscopy(TRLFS)techniques.The continuous increase in the fluorescence lifetime of Eu-alumina and Eu-FA with increasing pH indicates that the complexation is accompanied by decreasing number of hydration water in the first coordination sphere of Eu(Ⅲ).Eu(Ⅲ)is adsorbed onto alumina particles as outer-sphere surface complexes of≡(Al-O)-Eu·(OH)·7H_2O and≡(Al-O)-Eu·6H_2O at low pH values,and as inner-sphere surface complexes as≡(Al-O)_2-Eu^+·4H_2O at high pH.In FA solution,Eu(Ⅲ)forms complexes with FA as(COO)_2Eu^+(H_2O)_x and the hydration water number in the first coordination sphere decreases with pH increasing.The formation of≡COO-Eu-(O-Al≡)·4H_2O is observed on FA-alumina hybrids,suggesting the formation of strong inner-sphere surface complexes in the presence of FA.The surface complexes are also characterized by their emission spectra[the ratio of emission intensities of^5D_0→~7F_1(λ=594nm)and^5D_0→~7F_2(λ=619nm)transitions]and their fluorescence lifetime.The findings is important to understand the contribution of FA in the complexation properties of Eu(Ⅲ)on FA-alumina hybrids that the clarification of the environmental behavior of humic substances is necessary to understand fully the behavior of Eu(Ⅲ),or its analogue trivalent lanthanide and actinide ions in natural environment.
