Construction And Application Of Novel Photocatalysts Based On Nanocarbon Materials

With the deepening research of semiconductor materials for the serious energy andenvironmental crisis, it has got rapid development on chemical transfer and storage of solarenergy, which is the fundamental way to solve the problem of environmental pollution andenergy crisis in the development of human society. In recent years, the photocatalyticdegradation of organic pollutants, solar fuel cells, photocatalytic splitting of water andphotocatalytic carbon dioxide fixation have been developed rapidly. However, the existingstudies on the utilization of solar energy chemical conversion are very low, far short of therequirements of practical applications. How to improve the utilization of solar energy becomesthe core issue in this research field.Based on the popular research fields and problems need to be solved in photocatalyticapplication as mentioned above, the target of this paper focused on the construction of novelphotocatalysts to improve the photocatalytic efficiency of H2generation and CO2reduction.The strategy is to employ the nanocarbon materials as the basic unit and introduce themechanism of multiple electron transfer channels, multiple exciton generation, spatialseparation of carriers, extending the radical life into the construction of photocatalysts. In thenovel photocatalysts, nanocarbon materials serve as the electron acceptor and active sitesprovider as well as the supporting matrix to anchor nanoparticles, which could improve thephotocatalytic efficiency greatly.In the first section, the basic structure of the catalyst constructed in this paper, carbonnanotubes and graphene oxide were introduced briefly, including their synthesis,characterization, modification and applications.In the second chapter, a dye-sensitized photocatalyst with three electron transitionchannels was constructed, in which FeOOH and photosensitizer RuL2Cl22H2O were employed as the electron donor, carbon nanotubes were served as the electron traps/container. Thecatalytic results for carboxylation reaction of phenol by CO2and TD-DFT calculation resultsindicated the catalyst possessed three electron transition channels assisted by intermolecularhydrogen bonding interaction.In the third chapter, a novel ZnO@PbS/GO photocatalyst was constructed based onmultiple exciton generation effect and applied in hydrogen generation. The presence of multipleexciton generation process, which was confirmed by transient absorption spectrum andphotocurrent measurements, remarkably improves the photocatalytic efficiency of hydrogengeneration.In the fourth chapter, a ZnO/(Cu-BTC)MOF/GO structure was constructed, which realizedthe spatial separation of photoelectron and hydrogen radical for the introduction of(Cu-BTC)MOF. The spatial separation avoided the oxidation of radical by holes in ZnO andextended its life. On the other hand, the MOF effectively stabilized the hydrogen radical andimproved the chances of its generating hydrogen molecules, so as to improve the efficiency ofphotocatalytic hydrogen production.In the last section, the products of different copper salt in diethylene glycol wassynthesized with the existence of GO. And their influence on photocatalytic hydrogengeneration was investigated with the characterization of the products.The results reported in this research paper as mentioned above should be much helpful toconstruct a novel photocatalyst with the synergistic effect of photoelectron generation andseparation for the photocatalytic efficiency improvement.