An active and stable photocatalyst to directly split water is desirable for solar-energy conversion. However, it is difficult to accomplish overall water splitting without sacrificial electron donors. Herein, we demonstrate a strategy via constructing a single site to simultaneously promote charge separation and catalytic activity for robust overall water splitting. A single Co -P site confined on g-C N nanosheets was prepared by a facile phosphidation method, and identified by electron microscopy and X-ray absorption spectroscopy. This coordinatively unsaturated Co site can effectively suppress charge recombination and prolong carrier lifetime by about 20 times relative to pristine g-C N , and boost water molecular adsorption and activation for oxygen evolution. This single-site photocatalyst exhibits steady and high water splitting activity with H evolution rate up to 410.3 μmol h g , and quantum efficiency as high as 2.2 % at 500 nm.

pH-driven method, an organic solvent-free and easily scale-upable method, was firstly utilized to prepared curcumin-loaded liposomes.

In this study, nanoemulsion-based delivery systems fabricated using three different methods were compared with three commercially available curcumin supplements. Powdered curcumin was dispersed into the oil-in-water nanoemulsions using three methods: the conventional oil-loading method, the heat-driven method, and the pH-driven method. The conventional method involved dissolving powdered curcumin in the oil phase (60 °C, 2 h) and then forming a nanoemulsion. The heat-driven method involved forming a nanoemulsion and then adding powdered curcumin and incubating at an elevated temperature (100 °C, 15 min). The pH-driven method involved dissolving curcumin in an alkaline solution (pH 12.5) and then adding this solution to an acidified nanoemulsion (pH 6.0). The three commercial curcumin products were capsules or tablets purchased from an online supplier: Nature Made, Full Spectrum, and CurcuWin. Initially, the encapsulation efficiency of the curcumin in the three nanoemulsions was determined and decreased in the following order: pH-driven (93%) > heat-driven (76%) > conventional (56%) method. The different curcumin formulations were then subjected to a simulated gastrointestinal tract (GIT) model consisting of mouth, stomach, and small intestine phases. All three nanoemulsions had fairly similar curcumin bioaccessibility values (74−79%) but the absolute amount of curcumin in the mixed micelle phase was highest for the pH-driven method. A comparison of these nanoemulsions and commercial products indicated that the curcumin concentration in the mixed micelles decreased in the following order: CurcuWin ≈ pH-driven method > heat-driven method > conventional method ≫ Full spectrum > Nature Made. This study provides valuable information about the impact of the delivery system type on curcumin bioavailability. It suggests that encapsulating curcumin within small lipid particles may be advantageous for improving its absorption form the GIT.