SUPPLEMENTARY INFORMATION. Green planting nanostructured single crystal silver

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1 SUPPLEMENTARY INFORMATION Green planting nanostructured single crystal silver Hong Zhao 1,3, Fei Wang 2, Yuesheng Ning 2, Binyuan Zhao 2,3*, Fujun Yin 3, Yijian Lai 2, Junwei Zheng 1*, Xiaobin Hu 2, Tongxiang Fan 2*, Jianguo Tang 4, Di Zhang 2 & Keao Hu 2 1 College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, , P. R. China 2 State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, , P. R. China. 3 Huaihai Institute of Technology, Jiangsu Marine Resources Development Research Institute, Lianyungang , P. R. China. 4 College of Chemistry, Chemical and Environmental Engineering, Qingdao University, Qingdao, , P. R. China Correspondence and requests for materials should be addressed to B.Z. (byzhao@sjtu.edu.cn), J.Z.( jwzheng@suda.edu.cn) or T.F.( txfan@sjtu.edu.cn) 1

2 Supplementary Table S1. Structural Parameters of monolithic activated carbon (MAC) used in this work. monolithic activated carbon BET Surface Area (m 2 /g) Pore Volume (single point) (cm 3 /g) Pore Size (4V/A by BET) (nm) Apparent Density (g/cm 3 ) MAC A MAC B Supplementary Table S2. Elemental composition in atomic percent (%) of monolithic activated carbon (MAC) as determined by X-ray photoelectron Spectroscopy (XPS) monolithic activated C O Zn Fe S Si Cl carbon MAC A MAC B Supplementary Figure S1 The optical photographs and SEM images of silver products obtained by immersing MAC in [Ag(NH 3 ) 2 ]NO 3 solution for 24 hr at different concentrations. (a,d)-100mm; (b,e)-10mm; (c,f)-5mm. 2

3 Supplementary Figure S2 SEM images of silver products obtained by immersing Cl-free MAC in 5 mm [Ag(NH 3 ) 2 ]NO 3 solution for 24 hr.(a)-low and (b)-high magnification of Ag products taken from sample on MAC. Supplementary Figure S3 SEM images of silver products obtained at 30 min after immersing MAC in 5 mm [Ag(NH 3 ) 2 ]NO 3 solution in the process of nanobelts growth. Nanosheets with irregular fringes and indentations were found. 3

4 Estimation of Ag growth capacity of MAC The estimation was performed to evaluate the upper limit of Ag growth capacity of MAC. It was assumed that Ag was solely obtained from the reduction by reductive groups on outer and inner surface, since other elements such as Zn, Fe, S, and Si should be in oxidized states and do not contribute to the yield of Ag product. It was further assumed that all the reductive groups should contain oxygen, since pure carbon and hydrocarbon are chemically inert under the mild reaction condition. Of course, not all oxygen-containing groups in MAC can be used to produce Ag. Therefore our estimation only gives the upper limit. To ease the estimation, it is still assumed that all the elements are evenly distributed. Finally, we also assume that one oxygen group can produce two Ag atoms, simply based on a proposed reaction, R-CHO+H 2 O+2Ag + R-COOH+2Ag+2H +. The calculation was based on three parameters of MAC: elemental composition (Hydrogen was not considered since XPS did not give such information. In addition, hydrogen is a light element, so that it will not affect the estimation seriously), density, and BET surface area. Given MAC B (Supporting Information Table S1 and S2) as an example, the atomic ratio is as follows: C(82.5%), O(13.64%), Zn(1.42%), Fe(0.36%), S(0.73%), Si(1.2%) and Cl(0.14%). The molecular weight of a hypothetical molecule containing 100 atoms is calculated to be Consider possible impurity compounds such as ZnO, Fe 2 O 3, SO 3, SiO 2 and ZnCl 2, the content of oxygen covalently bound to carbon skeleton in MAC (effective oxygen) should be 7.16%. The density of MAC is measured to be g/cm 3. Provided a 1 g MAC cube, the total number of effective oxygen is 1*7.16* /

5 = If there is no porous structure, the surface area is 6*(1/0.816) 2/3 =6.87 cm 2, and the number of effective oxygen on the outer surface is 6*( ) 2/3 = The exhaustion of all the oxygen-containing groups in the outer surface can only produce *2*108/ = g Ag. The BET surface area of MAC B is 517 m 2 /g. Therefore, through galvanic-cell reaction mechanism, the maximum yield of Ag product from 1 g MAC is * /6.87=0.3456g. In one test, we obtained g Ag from g MAC. In another, g Ag grew on g MAC. These experimental results amount to ca. 0.11g Ag growing from 1 g MAC, corresponding to 0.11/0.3456=31.5% of the growth capacity. 5