Preparation And Characterization Of Artificial Chloroplast Based On Natural Chloroplast

Solar energy, as one of the largest renewable and clean energy resources in the world, will play an essential role in addressing global energy and environmental issues. Artificial photosynthesis is a new, effective and eco-friendly way to utilize solar energy by mimicking the natural process of photosynthesis, through which plants, algae and many species of bacteria obtain energy by converting sunlight, water and carbon dioxide into carbohydrates and oxygen. Splitting water into hydrogen and oxygen through sunlight energy by inorganic semiconductor materials is also referred to as artificial photosynthesis. TiO₂ is the most commonly used semiconductor materials for its efficiency, low cost, and chemical stability; however its band gap (3.2eV) determines that TiO₂ can only utilize UV light with wavelength shorter than 387nm. Nano-structure, anion-doping and noble metal nanoparticles can improve the photocatalytic properties of TiO₂.Nature has been employing a very smart approach, photosynthesis, for solar energy utilization; and its sites is chloroplasts. Chloroplasts have inherited quite unique structural and functional features which greatly improve the efficiency of photosynthesis. In this work isolated chloroplasts were used as template to synthesize TiO₂ with nano-layered structure and N, P self-doping. Then Au nanoparticles were deposited onto TiO₂ and an Au/chloroplast-morph-TiO₂ (ACMT) composite system keeping chloroplasts'essential features. The samples are characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), nitrogen adsorption measurement, transient spectra (TRS) and UV-vis spectroscopy. The results show that with nano-layered structures ACMT achieve fast photo-induced electron transfer and long lifetime. N, P self-doping can enhance visible light utilization and Au nanoparticles can improve system's photocatalytic property especially water splitting efficiency. With this artificial photosynthesis system we also prove that nano-layered structure can improve semiconductor materials'photocatalytic property.