| Behind the rapid development of the global economy,a large number of non-renewable energy sources,such as coal,oil,natural gas and other fossil fuels,have brought about energy crisis and environmental pollution.These two major problems have seriously restricted the sustainable development of mankind.Finding and developing green and environmentally sustainable new energy has become an important issue for human survival and sustainable development.In existing new energy systems,such as wind energy,geothermal energy,tidal energy,and solar energy,solar energy is considered to be the best alternative to fossil energy because of its non-pollution,low cost,high energy consumption,and ubiquity.Speeding up the development and expanding the use of solar energy is one of the effective ways to alleviate the energy crisis and the increasingly serious environmental problems caused by fossil energy consumption.Photocatalytic technology based on semiconductor materials can not only use solar energy to treat environmental pollution,but also can directly convert solar energy into fuel.Therefore,it is praised as a green new technology and ideal way for humans to solve energy shortages and environmental pollution.The key to the practical application of semiconductor photocatalytic technology is the synthesis of photocatalytic material with high efficiency,stability and broad spectrum response.Although a wide variety of photocatalytic materials have been studied at present,products that can meet the above-mentioned performance and meet the actual needs have not yet appeared.Therefore,it is still necessary to vigorously develop new types of high-performance photocatalytic materials.As a promising functional material,niobate has attracted much attention.It is an excellent accelerator and a good carrier.It has a wide range of applications in photocatalytic research and industrial production.Many niobate materials have superior performance and wide range of uses due to their unique structure and physical and chemical properties,especially for environmental governance and green energy.In the catalytic reaction,niobate exhibits good catalytic activity and stability,and can synthesize a large amount of organic matter and can effectively degrade organic printing and dyeing wastewater.Sodium niobate is the most common niobate.In the catalytic reaction,niobate has good catalytic activity and stability,can synthesize a large amount of organic matter,can effectively degrade organic printing and dyeing wastewater.Sodium niobate is the most common niobate.Sodium niobate is used as a substrate for this investigation.The two part of this paper uses sodium niobate molecular sieve as the research matrix.The first part has synthesized a new material with new niobium and oxygen structure through the doping of strontium carbonate.The changes in the structure of niobium and oxygen are changed,and the physical and chemical properties are changed,such as optical band gap,adsorption and photocatalytic activity.In the second part,the composite was modified with sodium bismuth to degrade organic pollutants under visible light,and then the internal structure,photophysical properties and photocatalytic properties of the samples were studied.The specific contents are as follows:(1)Most niobium oxide has a distorted eight body niobium and oxygen structure.Only a few rare earth niobium oxides have tetrahedral niobium oxygen structure,and the structural changes from niobium oxygen eight to niobium oxide tetrahedron change the physical and chemical properties of optical band gap,adsorption and photocatalytic activity.In this paper,the sodium niobate molecular sieves with eight body niobium and oxygen structure were synthesized with sodium hydroxide and five oxide two niobium as raw materials by hydrothermal method.Then the strontium carbonate was doped by high temperature solid state method,and a small amount of sodium doped strontium niobate samples were prepared.The laser confocal Raman spectroscopy showed the existence of niobate tetrahedron structure in the sample,and the internal structure and optical properties of the samples were characterized by X ray diffraction,UV visible spectrophotometer,X ray photoelectron spectroscopy,temperature programmed desorption and inductively coupled plasma.With the increase of the content of niobium oxide tetrahedron in the sample,the increase of the lattice parameter was found by X-ray diffraction.The UV-visible spectrophotometer was used to characterize the increase of the band gap.X-ray photoelectron spectroscopy and temperature programmed desorption proved that The surface changes are more active to oxygen adsorption,so that the sample has a higher photocatalytic activity.(2)Synthetic composites are also an effective means for the development of high performance visible light photocatalysts.The research group has recently studied sodium antimonate sodium bismuth composite.We use sodium niobate bismuth sodium composite as a comparative experiment.In this paper,sodium niobate are modified by sodium bismuth.The photocatalytic properties of sodium niobate sodium bismuth composite material in the visible light range are obtained,and the photophysical properties and photocatalytic properties of sodium niobate sodium bismuth composite are studied.The UV VIS spectrophotometer shows that the sodium niobate sodium bismuth composite has visible light absorption.The samples are characterized by X ray diffraction,UV visible spectrophotometer and scanning electron microscope.According to sodium bismuth compound with different mass ratios,the effect of sodium bismuth on the composite was discussed. |
