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Modulating the electronic configuration by coupling multi-scale active sites for electrocatalytic conversion of CO 2 to CO is extremely challenging in terms of structural analysis and mechanism elucidation. Herein, a catalyst NiAD/AgNPs@CN with both atomic-level dispersed Ni and Ag nanoparticles on N-doped carbon substrate has been designed to reveal the true active sites and catalytic mechanism in complex materials. NiAD/AgNPs@CN exhibits CO Faraday efficiency (FE CO) of 99.97% at −0.88 V (vs. RHE) in H-type cell and 91.77% FE CO with a high current density of 79.70 mA/cm2 in flow cell. DFT calculations show that the tiny change in the energy level of spin electrons at atomic sites has a significant impact on the CO 2 activation. The regulation of atomic Ni on Ag sites is the main reason for improving CO 2 RR performance. This work gives a new understanding on the catalytic mechanism of composite materials structured by atomic-level dispersed metal and nanoparticles. [Display omitted] • Atomic dispersed Ni surrounding with Ag nanoparticles was designed for CO 2 RR. • The synergistic effect between Atomic Ni sites and Ag nanoparticles was deeply explored. • Experiments combined with DFT study revealed the CO 2 RR mechanism. • The tiny change of spin electrons state has a significant impact on the activation of CO 2. [ABSTRACT FROM AUTHOR]

In this study, thiolated magnetic iron oxide nanoparticles (Fe 3 O 4 -SH) were prepared and characterized in detail, which exhibited benign superparamagnetism and magnetic recoverability. And the adsorption and desorption processes for various heavy metals, including Pb 2+ , Ni 2+ , Zn 2+ and Cu 2+ , had been investigated comprehensively both in single and mixed systems using the Fe 3 O 4 -SH nanoparticles as adsorbents. The results showed that heavy metal ions could be removed rapidly depending on the complexation with the SH-groups on the Fe 3 O 4 -SH surface. Besides, the adsorption was all sensitive to pH and ionic strength while the nano-adsorbents had the highest adsorption capacity and rate for Ni 2+ according to the adsorption kinetics and thermodynamics. In addition, the corresponding competitive adsorption processes and desorption experiments reflected that Fe 3 O 4 -SH had the strongest affinity and adsorption selectivity for Pb 2+ , followed by Ni 2+ and finally by Cu 2+ and Zn 2+ . Generally, the present study might provide a serviceable direction for the future efforts towards the application of Fe 3 O 4 -SH nano-adsorbents in industrial wastewater treatments involving multiple heavy metal contaminants. [ABSTRACT FROM AUTHOR]

This paper is focusing on the synthesis and characterization of poly-crystalline ZnS nanotubes. The ZnS@ZnO core/shell nanorods were formed by replacing O 2− ions with S 2− ions released by hydrolyzed thioacetamide assisted by ethylene glycol; then, ZnS@ZnO core/shell nanorods were etched with potassium hydroxide solution to remove the ZnO core. Elaborate characterizations were carried out to show the fine crystalline structure. The key factor of preparing poly-crystalline ZnS nanotubes is the control over the replacement process of O 2− ions by S 2− ions with the assistance of ethylene glycol to inherit the morphology of ZnO nanorods. [ABSTRACT FROM AUTHOR]