The Synthesize Of Porphyrin Molecule And Photocatalytic Device Developed For Photocatalytic Hydrogen Production

With the rapid development of science and technology, Peoples require more and more energy. In the process of access to energy, combustion of fossil fuels causes a series of crises surrounding global energy and encironment. Therefore, the research of a renewable clean energy to become the primary task. And the use of photocatalytic water splitting for H2 production is the best way to solve these problems. The content mainly include photocatalyst and photocatalytic device. We will synthesize with good light-trapping ability of porphyrin, and improve the existing photocatalytic hydrogen production device. The main contents are as follow:(1) Through reading the literature, we find that porphyrin which are employed for photocatalytic hydrogen generation and dye-sensitized solar cells are mainly tetraphenylporphyrin and its derivatives. In this chapter, we successfully synthesize tetraphenylporphyrin,5-nitrophenyl-10,15,20-triphenylporphyrin,5-aminophenyl-10,15,20-triphenylporphyrin and 5-hydroxyphenyl-10,15,20-triphenyl porphyrin, and analyse their optical spectrum. Because the group on the phenyl group of the meso-position of phenylporphyrin is the donating electronic group, it has be interaction with porphyrin macrocycleπ-conjugated system, which leading to distortion of porphyrin macrocycle plane, and that causes its absorption peaks red shift. Because the group on the phenyl group of the meso-position of phenylporphyrin is the excluding electronic group, and that causes the electron density of porphyrin macrocycle to increase, making its absorption peak red shift along with the reduce in the electron transition energy level, resulting in broadening of the absorption bands. Therefore, tetraphenylporphyrin derivatives is a better photosensitizer, and they can effectively improve the photocatalytic activity.(2) Naphthalene is a rigid planar polycyclic aromatic hydrocarbons, its conjugation greater than benzene's. Naphthyl group is introduced at the meso-position decrease in the HOMO-LUMO gap and to elongate theπsystem unsymmetrically, resulting in broadening and red shift of the absorption bands. In view of this, we synthesize a series of naphthyl porphyrins and metalloporphyrins. And we prepare 5-hydroxyphenyl-10,15,20-trinaphthyl porphyrin sensitize the photocatalyst in solid grinding method. Then we demonstrate the photocatalyst can splitting water to H2 in LabSolar H2 device. (3) Nowadays, visible light photocatalytic device is limited by great heat, difficult to cooling and others issues. Photoreactors mainly include side irradiation type and top irradiation type. In response to these problems, we have successfully developed a inner irradiation type photoreactor with LED light source. It can easy to cooling and effectively improve the photo energy efficiency. We find that eosin-carbon nanotubes-CuO integrated system in the device generate H2 rate up to 185μmol/h, and energy consumption per unit of hydrogen production is 1.14μmol/h-kJ. Its energy utilization is 137 times than a side irradiation type photoreactor with halogen light source in the same conditions.