UiO-66-NH2, as typical visible light responsive Zr-based metal-organic frameworks (MOFs), has attracted great interest in recent years. However, rapid combination of the photoinduced carriers limits its further application. Here, we designed a facile precipitation-photoreduction method to post-synthetically decorate Ag/AgCl on the surface of UiO-66-NH2 and form a heterostructure. Metallic Ag can not only transmit electrons between UiO-66-NH2 and AgCl but also absorb visible light, because of the surface plasmon resonance (SPR) effect. The rhodamine B photodegradation rate of UiO-66-NH2/Ag/AgCl (16.2 wt.% Ag) is about 10 and 4 times those of UiO-66-NH2 and Ag/AgCl, respectively. The SPR effect of Ag NPs and the formation of a heterostructure synergistically increase the absorbability of visible light, accelerate the separation of photoinduced charges, and promote the formation of superoxide radicals. We expect that our work could provide a new viewpoint for constructing efficient MOF-based photocatalytic systems.
Wanyue ZhaoTong DingYating WangMoqing WuWenfeng JinYe TianXingang Li
Lithium-sulfur （Li-S） batteries have drawn extensive attentions due to their high energy density, environmental friendliness and low cost. In this study, three-dimensional （3D） graphene/S hybrid （G/S） is prepared by a one-pot hydrothermal method together with redox reaction between S-based compound and graphene oxide （GO）. G/S has a three dimensional porous structure, where graphene is interconnected with each other forming a 3D conductive network. It demonstrates that the pore structure of G/S can be well controlled by optimizing the drying method of the 3D graphene-based materials. Freeze drying and evaporation-induced drying can induce different density and pore structure of G/S. Electrochemical tests illustrate that the resulting hybrid can deliver a specific capacity of 891 mAh·g^-1 and 575 mAh·g^-1 for the 1^st and 100^th cycle at a current density of 500 mAh·g^-1 .
Donghai LiuChen ZhangXiaohui LvXiaoyu ZhengLei ZhangLinjie ZhiQuan-Hong Yang
Herein, we prepared a series of H-Zn-mordenite (H-Zn-MOR) catalysts by adding zinc source into the initial sols during the synthesis of mordenite (MOR). The results indicated that isolated Zn ions were highly dispersed in the catalysts. The addition of zinc led to the increase of Si/Al in the framework of MOR,the change of the distribution of acid sites and the change of acid strength. We investigated the catalytic performance of the H-Zn-MOR catalysts and the HMOR catalysts for carbonylation of dimethyl ether to methyl acetate. The addition of zinc improved the catalytic performance and made the drop of the conversion over the Zn-0.003 and Zn-0.005 catalysts to be about the half of that over the HMOR catalyst.We attributed it to the change of the acid properties, which further change the rate of coke deposition.
Zhitao ZhangNa ZhaoKui MaQingpeng ChengJing ZhangLirong ZhengYe TianXingang Li
通过一步水热法制备出具有三维网络结构的氢氧化镍-石墨烯复合材料(Ni(OH)2-GS)。这一独特的结构可以提供良好的离子传输通道,同时可以有效地提高氢氧化镍与电解液的接触面积和材料的导电性。结果表明,Ni(OH)2的质量分数为84%时,复合材料具有最佳的电化学性能,在5 m V·s-1的扫速下比电容为1 461 F·g-1,在100 m V·s-1的扫速下比电容为682 F·g-1(容量保持率为47%),并且具有良好的循环稳定性。
