Facile Fabrication Of Carbon-and Boron-doped Carbon Nitride Nanomaterials And Their Photocatalytic Performance

In recent years,the rapid development of industry has aggravated the problem of energy shortage and environmental pollution.Scientists all over the world attach great importance to the development of green and clean energy and efficient pollution control technology.However semiconductor photocatalytic technology has become one of the most widely used technologies to solve environmental pollution and energy crisis due to its advantages of high efficiency,small energy consumption and no secondary pollution.The core of photocatalytic technology lies in the performance and efficiency of photocatalytic materials,most of which are generally deficient in low utilization rate of solar energy and low photoquantum efficiency.Therefore,the development of new and efficient photocatalytic materials has become the main research topic in the field of photocatalysis.The g-C₃N₄ is characterized by moderate band gap,good thermal and chemical stability and low cost.However,g-C₃N₄ has many defects,such as low activity and small specific surface area,which seriously affect its wide application in practice.The effects of glucose and boric acid on the electronic structure of g-C₃N₄ were studied.The main research results are as follows:（1）The structure,morphology,electrochemical performance and photocatalytic activity of c-doped g-C₃N₄ composite were systematically studied,and the influence of glucose mass ratio on the photocatalytic performance of the composite was explored.The experimental results show that compared with the pure g-C₃N₄graphite-phase layered material,the specific surface area of c-doped g-C₃N₄composite material increases,the active site increases,and the photogenerated electron-hole composite rate significantly decreases（especially in the wavelength range of 425⁵25nm）,thus improving the photoquantum efficiency.At the same time,the absorption intensity of ultraviolet and visible light was enhanced.In addition,C doping increases the electron transfer rate by about four times.These results provide experimental basis for the manufacture of high efficient g-C₃N₄-based composite photocatalyst.（2）BN/g-C₃N₄ composites were prepared by thermal stripping method,and the influence of BN composites on the photocatalytic properties of the composites and the mechanism for improving the photocatalytic properties were systematically studied.The results show that BN/g-C₃N₄ composite has excellent adsorption capacity and degradation rate.The degradation rate of BN/g-C₃N₄ composite under ultraviolet light can reach 0.072min-1,which is twice the degradation rate of BN and g-C₃N₄,and four times the degradation rate of H₃BO₃.The successful combination of BN and g-C₃N₄expands the optical response range,and thus improves the optical quantum efficiency,providing experimental support for the preparation of efficient g-C₃N₄ based heterojunction.