Da Wang,Shiwen Dong,Lingsha Wen,Weiting Yu,Zhiqiao He,Qingqing Guo,Xiaohui Lu,Lizhang Wang,Shuang Song,Jun Ma
A metal oxide electrode has been developed for the electrochemical CO 2 reduction reaction (eCO 2 RR). It exhibits superior activity and product selectivity towards eCO 2 RR by circumventing the previously encountered problem of self-reduction with high-valence metals. Specifically, a hydrocerussite [Pb 3 (CO 3 ) 2 (OH) 2 ] thin film has been synthesized in situ on a Pb substrate (denoted as ER-HC) by an electroreduction method using a lead-based metal–organic framework (Pb-MOF) as a precursor. The ER-HC electrode exhibits a high selectivity of 96.8% towards HCOOH production with a partial current density of 1.9 mA cm −2 at −0.88 V vs. the reversible hydrogen electrode (RHE). A higher HCOOH partial current density of 7.3 mA cm −2 has been achieved at −0.98 V vs. RHE. Physicochemical and electrochemical characterization results demonstrate that the defective hydrocerussite surface exhibits appropriate adsorption free energy of formate (HCOO − ) and a lower reaction free energy for HCOOH production from CO 2 , which greatly boosts the eCO 2 RR activity and HCOOH production selectivity. The structure and eCO 2 RR performance of the hydrocerussite thin film remain stable in 0.1 M KHCO 3 as electrolyte, ensuring its durability. Overall, this work not only provides a metal oxide electrode (metal hydroxide, to be more precise) with excellent eCO 2 RR performance, but also expands the in situ electrochemical derivatization strategy for the fabrication of metal oxide electrodes.
Tie luo (affixed hanging) was an expressive form of traditional Chinese calligraphy or paintings, and popular in the imperial palaces for interior decorations in Qing Dynasty (1644–1911 C.E.). A piece of calligraphic tie luo , written by an eminent calligrapher Gu Gao (1763–1832 C.E.), was restored recently in the Palace Museum, Beijing, China. The paper with pigment coating specially made for this calligraphic piece was named as fenjian . This article presented results from materials identification prior to the restoration. Multianalysis with scientific approaches revealed how tie luo was manufactured. It could be concluded that the investigated tie luo used a paper made from bast fibers of mulberry trees. And the decorative ground layer for the piece was also studied, which indicated that a type of organic red pigments were used for the masterpiece. White lead was considered as the main pigment, mixed with a red dye extracted from sappanwood. Meanwhile, animal glue, drying oils and beeswax were confirmed as the organic binding media. In dye analysis, protosappanin B and brazilin as well as brazilein were identified, which implied that sappanwood was used for the organic manufacture of pigments. In addition, both Nowik type A and C were found in the research, which were characteristic of sappanwood for identification.
危险品化学品经营许可证（带存储）