镧系元素光化学 Ⅳ 铁和铈对光还原分离铕的影响

本文在水溶液中以1:1HCOOH～HCOONa做自由基清除剂,Na_2SO_4做光还原产物Eu^(2+)沉淀剂,研究了杂质铁和含量变化对光还原分离铕的影响,并用紫外光谱证明了体系中是光反应生成的Fe和Ce^(4+)对发生氧化,致使Eu^(2+)光还原生成Eu^(2+)速度减慢,铕的收率下降。

镧系元素光化学——Ⅲ.铕的光还原分离

本文报道了以低压汞灯做光源,HCO_2H-HCO_2Na做自由基清除剂,Na_2SO_4做光还原产物Eu(Ⅱ)的沉淀剂,在改变自由基清除剂、沉淀剂和稀土离子浓度、溶液的酸度和光强度的条件下,研究了从铕和其它镧系元素氯化物的二元混合物中光还原分离提取铕的问题,同时测定了沉淀的组成以及元素间的分离因数(β).

Research Progress in Photocatalytic CO_(2) Reduction with ZnIn_(2)S_(4)-Based Nanomaterials(Ⅰ)

Zinc indium sulfide(ZnIn_(2)S_(4),ZIS),a novel photocatalyst with layered nanostructure,has drawn significant attention in the field of photocatalytic CO_(2) reduction in recent years due to various advantages,including non-toxicity,structural stability,easy availability,and suitable band gap.We introduced the types of ZISbased nanomaterials and their action mechanism in photocatalytic CO_(2) reduction.Moreover,we put forward prospects in the future development directions of ZIS-based nanomaterials for photocatalytic CO_(2) reduction.

Facile fabrication of ZnIn2S4/SnS2 3D heterostructure for efficient visible-light photocatalytic reduction of Cr（Ⅵ）

Photocatalytic method has been intensively explored for Cr(VI)reduction owing to its efficient and environmentally friendly natures.In order to obtain a high efficiency in practical application,efficient photocatalysts need to be developed.Here,ZnIn2S4/SnS2 with a three-dimensional(3D)heterostructure was prepared by a hydrothermal method and its photocatalytic performance in Cr(VI)reduction was investigated.When the mass ratio of SnS2 to ZnIn2S4 is 1:10,the ZnIn2S4/SnS2 composite exhibits the highest photocatalytic activity with 100%efficiency for Cr(VI)(50 mg/L)reduction within 70 min under visible-light irradiation,which is much higher than those of pure ZnIn2S4 and SnS2.The enhanced charge separation and the light absorption have been confirmed from the photoluminescence and UV-vis absorption spectra to be the two reasons for the increased activity towards photocatalytic Cr(VI)reduction.In addition,after three cycles of testing,no obvious degradation is observed with the 3D heterostructured ZnIn2S4/SnS2,which maintains a good photocatalytic stability.

Research Progress in Photocatalytic CO_(2)Reduction with ZnIn_(2)S_(4)-Based Nanomaterials(Ⅱ)

Zinc indium sulfide(ZnIn_(2)S_(4),ZIS),a novel photocatalyst with layered nanostructure,has drawn significant attention in the field of photocatalytic CO_(2)reduction in recent years due to various advantages,including non-toxicity,structural stability,easy availability,and suitable band gap.We introduce the types of ZIS-based nanomaterials and their action mechanism in photocatalytic CO_(2)reduction.Moreover,we put forward prospects in the future development directions of ZIS-based nanomaterials for photocatalytic CO_(2)reduction.

Cooperation of oxygen vacancies and 2D ultrathin structure promoting CO2 photoreduction performance of Bi4Ti3O12

Reduction of CO2to solar fuels by artificial photosynthesis technology has attracted considerable attention. However, insufficient separation of charge carriers and weak CO2adsorption hamper the photocatalytic CO2 reduction activity. Herein, we tackle these challenges by introducing oxygen vacancies (OVs) on the two-dimensional Bi4Ti3O12ultrathin nanosheets via a combined hydrothermal and postreduction process. Selective photodeposition experiment of Pt over Bi4Ti3O12discloses that the ultrathin structure shortens the migration distance of photo-induced electrons from bulk to the surface, benefiting the fast participation in the CO2reduction reaction. The introduction of OVs on ultrathin Bi4Ti3O12 nanosheets leads to enormous amelioration on surface state and electronic structure, thereby resulting in enhanced CO2adsorption, photoabsorption and charge separation efficiency. The photocatalytic experiments uncover that ultrathin Bi4Ti3O12nanosheets with OVs reveal a largely enhanced CO2photoreduction activity for producing CO with a rate of 11.7 lmol g-1h-1in the gas–solid system, 3.2 times higher than that of bulk Bi4Ti3O12. This work not only yields efficient ultrathin photocatalysts with OVs, but also furthers our understanding on enhancing CO2reduction via cooperative tactics.

Tungsten bronze Cs0.33WO3 nanorods modified by molybdenum for improved photocatalytic CO2 reduction directly from air

Photocatalytic CO2 reduction is thought to be a promising strategy in mitigating the energy crisis and several other environmental problems.Hence,modifying or developing suitable semiconductors with high efficiency of photocatalytic CO2 reduction property has become a topic of interest to scientists.In this study,a series of Mo-modified Cs0.33WO3 tungsten bronze were prepared using a"watercontrollable releasing"solvothermal method to produce effective photocatalytic CO2 reduction performance.Interestingly,Mo atoms replaced W partially within the hexagonal crystal structure,leading to a significant increase in photocatalytic CO2 reduction activity of Cs0.33WO3.The 5%Modoped compound displayed the best performance,with the production yield rates of 7.5μmol g^-1h^-1 for CO and3.0μmol g^-1h^-1 for CH3OH under low concentration of CO2 under anaerobic conditions,which is greatly higher than those of pure Cs0.33WO3(3.2μmol g^-1h^-1 for CO and 1.2μmol g^-1h^-1 for CH3OH)and Mo-doped W18O49(1.5μmol g^-1h^-1for CO and 0μmol g^-1h^-1 for CH3OH).More importantly,the as-prepared Mo-doped Cs0.33WO3 series could also induce the photocatalytic reduction of CO2 directly from the air in the presence of oxygen,which is beneficial for practical applications.The superior photocatalytic performance of Mo-doped Cs0.33WO3 series over the popular reduced WO3 may be due to the increase in light absorption induced by the localized surface plasmon resonance(LSPR)effect of Mo5+,large improved charge separation ability,and the co-effect of Mo and Cs in crystal.This study provides a simple strategy for designing highly efficient photocatalysts in low concentration of CO2 reduction.