The electrocatalytic oxygen evolution reaction (OER) plays a critical role in sustainable energy conversion and storage, but OER is severely hampered owing to the lack of highly efficient catalysts. Here, we report an efficient electrocatalyst, with NiO/Co 3 O 4 nanoparticles decorated on nitrogen-doped carbon (NiO/Co 3 O 4 @ NC). Abundant high-valence Ni 3+ and Co 3+ species were observed on the surface of the hybrid due to the strong NC−metal oxide and NiO−Co 3 O 4 interactions. This unique structure leads to excellent OER performance, delivering a very low overpotential of 240 mV@10 mA•cm −2 on glassy carbon and 200 mV@10 mA•cm −2 on Ni foam in KOH and having a turnover frequency (@350 mV overpotential) 6 and 16 times higher than that of IrO 2 and RuO 2 , respectively.

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The effect of guar gum in capsule form on serum total cholesterol, triglycerides, and lipoprotein cholesterol (very low-density lipoproteins, low-density lipoproteins, and high-density lipoproteins) was studied in healthy volunteers in this double-blind study. Twenty-four subjects equally divided into treatment and placebo groups, received 9.0 g/day of guar and glucose in 600 mg identical capsules, respectively, for 4 wk under conditions of constant body weight and dietary stability. Guar significantly lowered serum total cholesterol (16.6% p less than 0.05) and low-density lipoprotein cholesterol (25.6% p less than 0.05) but had no significant effect (p less than 0.05) on serum triglycerides, high-density lipoproteins and very low-density-lipoprotein cholesterol. No significant changes (p greater than 0.05) were seen in blood lipids in the placebo group.

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Co–Mo2N@NC exhibits comparable hydrogen evolution reaction activity with that of Pt/C because of the improvement of intrinsic activity and electrical conductivity.

N-doped carbon materials are the promising oxygen reduction reaction (ORR) electrocatalyst for many energy systems such as fuel cells and metal−air batteries. Here we report a facile method to regulate electronic structures of bamboo-like carbon tubules dually by rich N-doping and Co particles decoration via pyrolysis of HNO 3 -treated melamine with Co(OH) 2 nanoparticles in an Ar environment (Co-NC-T). XRD, XAFS, and Raman spectra indicate the abundant decoration of metal Co rather than CoO x , and XPS spectra confirm the rich N-doping (7.6%) and abundant Co-NC sites in Co-NC-700, which shows superior ORR activities in 0.1 M KOH with the onset potential of 0.95 V, half-wave potential of 0.90 V, good stability, and methanol tolerance ability. The deformation charge density and adsorption energies (DFT) indicate the dual electronic regulations by N-doping and metal Co can significantly accelerate O 2 adsorption and improve conductivity, which are beneficial for ORR performance of carbon materials. This work provides a facile method to obtain highly active carbon materials via the electronic regulation for efficient catalysis.