We present composition-controlled synthesis of ZnO-Zn composite nanoparticles by laser ablation of a zinc metal target in pure water or in aqueous solution of sodium dodecyl sulfate (SDS). By SDS concentration, composition and size of the nanoparticles can be controlled in a wide range. Relative amounts of the components Zn and ZnO, the particle size, and the microstructure can evolve with SDS concentration in solution. High SDS concentration corresponds to high relative amount of Zn nanoparticles existing as the core in the core/shell nanostructures, whereas low SDS concentration leads to high ZnO amount. This was explained by a dynamic mechanism on the basis of the competition between aqueous oxidation and SDS capping protection. Correspondingly, optical absorption spectra evolve from the excitonic peak of ZnO (about 350 nm) to the Zn surface plasmon resonance (about 242 nm) with rise of SDS concentration. A blue (about 450 nm) photoluminescence was observed in the obtained ZnO nanoparticles, which was attributed to existence of interstitial zinc in ZnO lattices. This study has revealed that laser ablation of active metal in liquid media is an appropriate method to synthesize a series of metal oxide semiconductor-metal composite nanoparticles with controlled composition and size.

The crystal structure of human endostatin reveals a zinc-binding site. Atomic absorption spectroscopy indicates that zinc is a constituent of both human and murine endostatin in solution. The human endostatin zinc site is formed by three histidines at the N terminus, residues 1, 3, and, 11, and an aspartic acid at residue 76. The N-terminal loop ordered around the zinc makes a dimeric contact in human endostatin crystals. The location of the zinc site at the amino terminus, immediately adjacent to the precursor cleavage site, suggests the possibility that the zinc may be involved in activation of the antiangiogenic activity following cleavage from the inactive collagen XVIII precursor or in the cleavage process itself.

Reducing the poisoning effect of alkali and heavy metals over ammonia selective catalytic reduction (NH3-SCR) catalysts is still an intractable issue, as the presence of K and Pb in fly ash greatly hampers their catalytic activity by impairing the acidity and affecting the redox properties of the catalysts, leading to the reduction in the lifetime of SCR catalysts. To address this issue, we propose a novel self-protected antipoisoning mechanism by designing SO4 2–/TiO2 superacid supported CeO2–SnO2 catalysts. Owing to the synergistic effect between CeO2 and SnO2 and the strong acidity originating from the SO4 2–/TiO2 superacid, the catalysts show superior catalytic activity over a wide temperature range (240–510 °C). Moreover, when K or/and Pb are deposited on SO4 2–/TiO2 catalysts, the bond effect between SO4 2– and Ti–O would be broken so that the sulfate in the bulk of SO4 2–/TiO2 superacid support would be induced to migrate to the surface to bond with K and Pb, thus prohibiting poisons from attacking the Ce–Sn active sites, and significantly boosting the resistance. Hopefully, this novel self-protection mechanism derived from the migration of sulfate in the SO4 2–/TiO2 superacid to resist alkali and heavy metals provides a new avenue for designing novel catalysts with outstanding resistance to alkali and heavy metals.

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