A facile aqueous-phase synthesis of Co-based nanostructures composed of cobalt hydroxide and cobalt oxide for enhanced photocatalytic activity of dye-sensitized H2 production

Enhanced Photocatalytic Hydrogen Evolution by Star-Shaped Viologen-Sensitized TiO2 Nanoparticles

“…Inspired by this idea, photocatalytic H 2 evolution has been considered an ideal and feasible technology as a green process for solar-driven water splitting. − H 2 can be generated from the photocatalytic decomposition of water by using appropriate catalysts that absorb the light in the available region of the solar spectrum, and this energy is generated by conversion into photogenerated charges to drive surface redox reactions. , Since TiO 2 as a semiconductor photocatalyst was implemented in 1972 for water-splitting, it has been extensively studied due to its low cost, nontoxicity, high photostability, and great redox capacity. − However, the wide band gap ( E g = 3.2 eV) and the high recombination rate of TiO 2 limit its further applications. , To overcome these obstacles, many studies have been conducted, including atomic doping, − metal deposition, − semiconductor incorporation, − photosensitization, etc. , The photosensitization has been known as an effective way to extend the photoresponse of inorganic semiconductors to the visible-light region . Efficient photosensitizers have been reported to date, for instance, a Ru­(bpy) 3 2+ metal complex, squarylium dyes, quaterthiophene, thienopyrazine-triarylamine, perylene-quinoxaline, multi-carbazole, and xanthene dyes for hydrogen evolution systems. − The reduction of photosensitizers of the methyl viologen with suitable electron donors and subsequent hydrogen production was achieved with the aid of noble metal cocatalysts. , Kotani et al systematically investigated photocatalytic H 2 evolution using platinum clusters functionalized with methyl viologen-alkanethiol (MVA 2+ ) and a simple electron-donor dyad. The amount of H 2 evolution of the MVA 2+ –Pt C system was estimated to be 2.4 μmol h –1 in the presence of a NADPH sacrificial agent .…”

Synthesis of Temperature Sensing Nitrogen-Doped Carbon Dots and Their Application in Fluorescent Ink

“…Cobalt exerts its good physicochemical properties in many fields, such as batteries, electrocatalysis, and photocatalysis [ 1 , 2 , 3 , 4 ]. And in biology, cobalt is an important micronutrient, and as one of the metal ions necessary for the formation of vitamin B complexes in the body, it is involved in the regulation of various body functions.…”