Silver foams with high porosity and electrical conductivity have many potential applications in energy storage, catalysis, and fuel cells. However, its application is largely hindered by the low efficiency of complicated synthesis processes. In this work, a facile and rapid bottom-up fabrication of silver foams in an aqueous solution allowing large-scale production through oriented and additive nanojoining of silver nanoplate building blocks is reported. Self-assembling of as-grown silver nanoplates facilitates the oriented nanoscale joining to align the atomic lattice, and the local additive of silver promotes diffusion and interconnection at room temperature to realize a rapid synthesis process. The freeze-dried silver foam exhibits a porosity of 95.45%, an ultralow density of 61 mg·cm–3, low thermal conductivity of 0.29 W·m–1·K–1, and high electrical conductivity of 8086 S·m–1. This oriented and locally additive nanojoining process presents a new strategy to fabricate silver foams that may also inspire the fabrications of other metal foams.
Keliang Song,Zhuoni Jiang,Fangfang He,Yongsheng Li,Zhiyu He,Yintao Li,Peng Wang,Guansong He,Wenbin Yang
Inorganic hydrated salts possess high latent heat of phase transition and are promising phase change materials (PCMs). However, the issues of supercooling, low thermal conductivity , susceptibility to leakage, and phase separation significantly impediment the practical applications of inorganic hydrated salts. In this study, it is proposed to decrease the inorganic hydrated salt supercooling degree by increasing the surface roughness of the porous material and to load the nucleating agent silver (Ag) onto polydopamine (PDA) modified melamine foam (MF) by electroless plating to obtain 3D porous Ag foams, which are then utilized as support materials. The results demonstrated that the 3D porous Ag foam compounded with barium hydroxide octahydrate (BHO) can ameliorate the shortcomings of leakage and reduce the supercooling degree in the cooling process. The composite not only exhibits high enthalpy of over 248.5 J/g and high thermal conductivity of 1.82 W·m −1 ·K −1 but also has a low supercooling degree of 0.21 ℃. Furthermore, the composites exhibited superior shape stability and thermal cycling stability. This study provides an effective method for reducing the supercooling degree of inorganic hydration salts.
Da Wang,Ying Zhu,Weiting Yu,Zhiqiao He,Feilong Dong,Yi Shen,Tao Zeng,Xiaohui Lu,Jun Ma,Lizhang Wang,Shuang Song
Ag-based electrodes have emerged as important candidates for the industrial electrochemical CO 2 reduction reaction (eCO 2 RR) to form CO. Herein, an intrinsic versatile Ag electrode has been derived in situ from Ag-MOF on Ag foam (denoted as ER-AF), which exhibits the highest current density (57.2 mA cm −2 ) at a potential of −1.15 V vs. RHE reported to date for the formation of CO in a commonly used H-type cell. ER-AF has multiple-roles: The 3D dendrite structure promotes mass diffusion; the rich edges sites favor CO 2 adsorption and conversion, and the highly exposed (111) facet facilitates the desorption of CO. Their cooperating functions result in the remarkable performance of ER-AF in the eCO 2 RR to form CO. This work offers an effective strategy to achieve high eCO 2 RR activity and selectivity by assembling the active and stable sites together on the MOF-derived materials.
危险品化学品经营许可证（带存储）