Photocatalysis Of Semiconductor By First-principle Calculation

Since the industrial revolution,fossil energy has entered people's lives.With the rapid consumption of coal and oil,these non-renewable resources into a near-exhausted situation,according to our current fossil energy extraction speed and consumption rate of view,the world's proven oil reserves for only 40 years,while Natural gas can only be mined for 60 years.In the late part of this century,people will face a huge energy crisis,It is emergent to find new energy materials to replace the fossil fuels.With the consumption of fossil fuels,environmental problems are becoming more and more serious.A large number of fossil fuel combustion caused by nitrogen,sulfur pollutants seriously pollute the atmospheric environment,causing serious acid rain phenomenon;even after cleaning the fossil energy,a large number of carbon dioxide emissions still exacerbate the Earth's greenhouse effect.These problems continue to threaten the survival of animals and plants,erosion of human survival environment,affecting people's health.The face of human daily huge amount of energy consumption,the development of clean and pollution-free new energy is imperative.Solar energy,as the original source of earth energy,has the characteristics of abundant reserves,clean and reliable.If you can make good use of solar energy,will be a good solution to the Earth's energy problems.In the use of solar energy,a suitable solar energy can absorb the semiconductor material is particularly important.Through the photocatalytic semiconductor materials can be directly absorbed by the decomposition of hydrogen water to get clean hydrogen energy;at the same time can use photocatalytic materials can break down pollutants,effectively alleviate the Earth's problems.In recent years,in order to make better use of solar energy,people in the experimental and theoretical have carried out a lot of exploration,and the key to the use of solar energy is to find a suitable photocatalytic material.In this paper,from the traditional photocatalytic material-titanium dioxide,through the self-made genetic algorithm based on the structure search software to obtain the new crystal structure of titanium dioxide.We studied the band characteristics of various TiO structures and found that the bandgap of titanium dioxide crystals showed a decreasing trend with the increase of the coordination number of Ti atoms.And we directly predict a new titanium dioxide phase with a direct band gap of 1.5eV.We have further obtained the two-dimensional titanium dioxide thin film structure with 6(2),and found a titanium dioxide thin film with two-dimensional hexagonal structure with 2.0eV indirect bandgap.We found a zigzag shear curled hexagonal film by cutting and curling the film,which had a good indirect band gap,and the band gap width did not change greatly with the diameter of the tube,easy to use in the laboratory preparation.We further explored the catalytic performance of organic catalysts.Through a variety of functional groups modified phthalocyanine derivatives,and to obtain a variety of suitable for photocatalytic organic materials.