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The effect of hydrogen peroxide leaching of silver was studied on the basis of traditional nitric acid leaching of silver from spent silver catalysts. The silver leaching rate was 99.76% by slowly adding hydrogen peroxide in the conditions of 2 mol/L HNO3, leaching temperature 70 °C, leaching time 120 minutes, and solid-liquid ratio 1:4, which had good leaching effect. Hydrogen peroxide oxidizes Ag to Ag2O, which can effectively improve the leaching rate of silver, while the nitrogen oxide produced by the reaction between nitric acid and silver is oxidized by H2O2 to generate nitric acid and continue to participate the reaction. The use of nitric acid hydrogen peroxide as a leaching agent ensures efficient silver leaching, reduces the emission of nitrogen oxides, and provides a theoretical basis and technical support for the green and efficient recovery of spent silver catalysts. [ABSTRACT FROM AUTHOR]

TiO2 nanotube arrays (TNTAs) were prepared by anodic oxidation with a tube diameter of 60 nm and a tube length of 5.4/im. Further Au- and Ag-modified TNT As/Au and TNT As/Ag nanotube arrays were prepared by electrodeposition. The effects of loading with different Au and Ag contents on the photoanodic photo-electrocatalytic conversion of glycerol-coupled hydrogen production coupling were evaluated. The results showed that TNT As loaded with Au and Ag could photo catalytically convert glycerol into high value-added products such as glyceraldehyde (GLI)) and dihydroxy ace tone (T)H A) and produce hyd rogen synergistically. TNT As/Au (0.08 m mol/L) and TNT As/Ag (0.04 mM) showed the highest catalytic performance with hydrogen production rates of 213.8/imol/cm²/h and 198.1/imol/cm1/h, glycerol conversion of 4.6 % and 4.4%, and T)H A selectivity of 15.4% and 15.3%, respectively. The best performance of the samples was attributed to the plasmon resonance effect of the metal nanoparticles, i.e., the metal acted as an electron trap to effectively gather the photoexcited electrons, and the electrons in the TiO2 conduction band were transferred to the metal to prevent the compounding of photogenerated electron-hole pairs, which effectively improved the catalytic performance of the TiO2 nanotube arrays. [ABSTRACT FROM AUTHOR]

By mixing manganese dioxide supported silver with AN-VDC copolymer and using DMF as the solvent the ab sorbable and catalytic AN-VDC copolymer nanofibers is prepared by electrospinning. The content of manganese dioxide supported silver as inorganic adding mixture in AN-VDC copolymer electrospinning liquid the influ ences of the dispersibility of manganese dioxide supported silver and the spinning parameters on the morphology of nanofibers are researched then the optimum spinning parameters are determined. The results show that the concentration of AN -VDC copolymer is 16% spinning voltage is 25 kV adding 25% of manganese dioxide sup ported silver and 1.6% of PVP dispersant made manganese dioxide supported silver good dispersion in the nanofibers. [ABSTRACT FROM AUTHOR]