Iron plaque is a Fe-containing oxide film produced by the oxidation of Fe(II)in the rice root system under the combined action of oxygen infiltration and other microorganisms.Owing to its special surface structure and...Iron plaque is a Fe-containing oxide film produced by the oxidation of Fe(II)in the rice root system under the combined action of oxygen infiltration and other microorganisms.Owing to its special surface structure and physio-chemical properties,the iron plaque has a strong absorption capacity for a variety of heavy metal ions.This study aimed to first investigate the effects of Fe species on the geochemical fractionation of Tl in typical paddy soil systems affected by industrial activities,followed by pot culture experiments to probe the effects of Fe species on the uptake and translocation of Tl in rice plants.The results of field work preliminarily showed that iron at different valences affected the conversion of the Tl geochemical fraction in the soil.Oxidizable Tl exerted significant positive correlation relationships with Fe2+and negative correlation relationships with Fe3+,while reducible Tl only displayed a positive correlation with Fe3+.Further analysis by pot culture experiments revealed that the contents of Fe were significantly positively correlated with Tl contents in Fe plaque(R2=0.529).In contrast,the water-soluble Tl contents in the soil were significantly negatively correlated with the contents of Fe(R2=–0.90,p<0.05).It suggests that the iron plaque promoted the absorption and fixation of Tl on the root surface of rice plants,causing Tl to accumulate in the iron plaque.Besides,the Tl content in the Fe plaque on the root surface of rice plants was greater than that in the above-ground tissues,which indicates that most Fe plaque exerts a certain degree of inhibition on Tl migration into the above-ground tissues of rice plants.All these findings indicate that Fe film is also an important carrier of Tl transfer in the soil–rice plant system,which provides new scientific support for the remediation of typical Tl-contaminated rice fields.展开更多
Solid oxide electrolysis cell(SOEC)is a promising technology for CO_(2) conversion and renewable energy storage with high efficiency.It is highly desirable to develop catalytically active cathodes for CO_(2) electroly...Solid oxide electrolysis cell(SOEC)is a promising technology for CO_(2) conversion and renewable energy storage with high efficiency.It is highly desirable to develop catalytically active cathodes for CO_(2) electrolysis.Herein,cathode materials with different structural stabilities are designed by Nb substitution on La_(0.5)Sr_(0.5)Fe_(0.8)Co_(0.2)O_(3-δ)(LSFC82)to obtain La_(0.5)Sr_(0.5)Fe_(0.7)Co_(0.2)Nb_(0.1)O_(3-δ)(LSFCN721)and La_(0.5)Sr_(0.5)Fe_(0.8)Co_(0.1)Nb_(0.1)O_(3-δ)(LSFCN811),respectively.LSFC82-Sm_(0.2)Ce_(0.8)O_(2-δ)(SDC)cathode with inferior structural stability(ability to maintain the structure)shows desirable CO_(2) electrolysis performance with the generated current density of 1.80 A cm^(-2)2 at 1.6 V and stable performance during 110 h operation at 1.2 V and 800℃.However,LSFC82 particles are collapsed into pieces after stability test with the generation of Co nanoparticles simultaneously.The frameworks of LSFCN721 and LSFCN811 particles maintain well because of the high-valent niobium,but Co exsolution,ox-ygen vacancy content and the corresponding CO_(2) electrolysis performance are restricted.This work confirms that Co nanoparticles can be exsolved from LSFC82-SDC cathode during CO_(2) electrolysis,providing references for constructing metallic nanoparticles decorated-perovskite cathodes for SOECs.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42173007,41830753,41873015)Natural Science Foundation of Guangdong Province,China(Nos.2021B1515020078,2021A1515011588,2014A030313527,the one granted to Jin Wang starting from 2023)+1 种基金Earth Critical Zone and Eco-geochemistry(No.PT252022024)the“Challenge Cup”program(Xiaoyin Zhang,Han Cai,Yuhua Zhang,Haoran Li,Mengqing Sun,Wenhuan Yuan and Ying Zhang).
文摘Iron plaque is a Fe-containing oxide film produced by the oxidation of Fe(II)in the rice root system under the combined action of oxygen infiltration and other microorganisms.Owing to its special surface structure and physio-chemical properties,the iron plaque has a strong absorption capacity for a variety of heavy metal ions.This study aimed to first investigate the effects of Fe species on the geochemical fractionation of Tl in typical paddy soil systems affected by industrial activities,followed by pot culture experiments to probe the effects of Fe species on the uptake and translocation of Tl in rice plants.The results of field work preliminarily showed that iron at different valences affected the conversion of the Tl geochemical fraction in the soil.Oxidizable Tl exerted significant positive correlation relationships with Fe2+and negative correlation relationships with Fe3+,while reducible Tl only displayed a positive correlation with Fe3+.Further analysis by pot culture experiments revealed that the contents of Fe were significantly positively correlated with Tl contents in Fe plaque(R2=0.529).In contrast,the water-soluble Tl contents in the soil were significantly negatively correlated with the contents of Fe(R2=–0.90,p<0.05).It suggests that the iron plaque promoted the absorption and fixation of Tl on the root surface of rice plants,causing Tl to accumulate in the iron plaque.Besides,the Tl content in the Fe plaque on the root surface of rice plants was greater than that in the above-ground tissues,which indicates that most Fe plaque exerts a certain degree of inhibition on Tl migration into the above-ground tissues of rice plants.All these findings indicate that Fe film is also an important carrier of Tl transfer in the soil–rice plant system,which provides new scientific support for the remediation of typical Tl-contaminated rice fields.
基金We gratefully acknowledge financial support from the National Key R&D Program of China(Grant 2017YFA0700102)the National Natural Science Foundation of China(Grants 92045302 and 22072146)+1 种基金the DNL Cooperation Fund,CAS(DNL201923)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant XDB17020200).
文摘Solid oxide electrolysis cell(SOEC)is a promising technology for CO_(2) conversion and renewable energy storage with high efficiency.It is highly desirable to develop catalytically active cathodes for CO_(2) electrolysis.Herein,cathode materials with different structural stabilities are designed by Nb substitution on La_(0.5)Sr_(0.5)Fe_(0.8)Co_(0.2)O_(3-δ)(LSFC82)to obtain La_(0.5)Sr_(0.5)Fe_(0.7)Co_(0.2)Nb_(0.1)O_(3-δ)(LSFCN721)and La_(0.5)Sr_(0.5)Fe_(0.8)Co_(0.1)Nb_(0.1)O_(3-δ)(LSFCN811),respectively.LSFC82-Sm_(0.2)Ce_(0.8)O_(2-δ)(SDC)cathode with inferior structural stability(ability to maintain the structure)shows desirable CO_(2) electrolysis performance with the generated current density of 1.80 A cm^(-2)2 at 1.6 V and stable performance during 110 h operation at 1.2 V and 800℃.However,LSFC82 particles are collapsed into pieces after stability test with the generation of Co nanoparticles simultaneously.The frameworks of LSFCN721 and LSFCN811 particles maintain well because of the high-valent niobium,but Co exsolution,ox-ygen vacancy content and the corresponding CO_(2) electrolysis performance are restricted.This work confirms that Co nanoparticles can be exsolved from LSFC82-SDC cathode during CO_(2) electrolysis,providing references for constructing metallic nanoparticles decorated-perovskite cathodes for SOECs.
