Different proportions of oxide-rich PdCu/C nanoparticle catalysts were prepared by the NaBH 4 reduction method, and their compositions were tuned by the molar ratios of the metal precursors. Among them, oxide-rich Pd 0.9 Cu 0.1 /C (Pd:Cu = 9:1, metal atomic ratio) exhibits the highest electrocatalytic activity for ethanol oxidation reaction (EOR) in alkaline media. X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM) confirmed the existence of both Cu and CuO x in the as-prepared Pd 0.9 Cu 0.1 /C. About 74% of the Cu atoms are in their oxide form (CuO or Cu 2 O). Besides the synergistic effect of Cu, CuO x existed in the Pd-Cu bimetallic nanoparticles works as a promoter for the EOR. The decreased Pd 3d electron density disclosed by XPS is ascribed to the formation of CuO x and the spill-over of oxygen-containing species from CuO x to Pd. The low Pd 3d electron density will decrease the adsorption of CH 3 CO ads intermediates. As a result, the electrocatalytic activity is enhanced. The onset potential of oxide-rich Pd 0.9 Cu 0.1 /C is negative shifted 150 mV compared to Pd/C. The oxide-rich Pd 0.9 Cu 0.1 /C also exhibited high stability, which indicated that it is a candidate for the anode of direct ethanol fuel cells (DEFCs).

Iron oxide nanoparticles (IONPs) are extensively used in bone-related studies as biomaterials due to their unique magnetic properties and good biocompatibility. Through endocytosis, IONPs enter the cell where they promote osteogenic differentiation and inhibit osteoclastogenesis. Static magnetic fields (SMFs) were also found to enhance osteoblast differentiation and hinder osteoclastic differentiation. Once IONPs are exposed to an SMF, they become rapidly magnetized. IONPs and SMFs work together to synergistically enhance the effectiveness of their individual effects on the differentiation and function of osteoblasts and osteoclasts. This article reviewed the individual and combined effects of different types of IONPs and different intensities of SMFs on bone remodeling. We also discussed the mechanism underlying the synergistic effects of IONPs and SMFs on bone remodeling.

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In this paper, we report that WO x containing nanoalloys exhibit stable electrocatalytic performance in alkaline media, though bulk WO 3 is easy to dissolve in NaOH solution. Carbon supported oxide-rich Pd-W alloy nanoparticles (PdW/C) with different Pd:W atom ratios were prepared by the reduction-oxidation method. Among the catalysts, the oxide-rich Pd 0.8 W 0.2 /C (Pd/W = 8:2, atom ratio) exhibits the highest catalytic activity for the oxygen reduction reaction. The X-ray photoelectron spectroscopy data shows that~40% of Pd atoms and~60% of the W atoms are in their oxide form. The Pd 3d 5/2 binding energy of the oxide-rich Pd-W nanoalloys is higher than that of Pd/C, indicating the electronic structure of Pd is affected by the strong interaction between Pd and W/WO 3. Compare to Pd/C, the onset potential of the oxygen reduction reaction at the oxide-rich Pd 0.8 W 0.2 /C shifts to a higher potential. The current density (mA•mg Pd −1) at the oxide-rich Pd 0.8 W 0.2 /C is~1.6 times of that at Pd/C. The oxide-rich Pd 0.8 W 0.2 /C also exhibits higher catalytic stability than Pd/C, which demonstrates that it is a prospective candidate for the cathode of fuel cells operating with alkaline electrolyte.