Study On Photocatalytic Water Splitting Performance Of Oriented And Highly Exposed {010} TiO₂ Fibers Modified By G-C₃N₄ And MoSe₂

Energy shortage and environmental pollution have gradually become the two major factors restricting the development of human society,and they have received more attention since the 21st century.Photocatalytic water splitting to produce hydrogen is considered to be one of the most ideal ways to solve energy and environmental crisis.TiO₂ has high photocatalytic activity and good stability,and it has been one of the most widely studied materials.By means of crystal plane control,photocatalytic performance of TiO₂ can be significantly improved,while there are still problems such as low quantum efficiency and serious carrier recombination.In this paper,based on high-exposure{010}TiO₂ nanobelts,electrospinning is used to achieve continuous assembly,and promoted charge transfer between crystal planes was obtained.And the high-exposure{010}TiO₂ fiber was successfully prepared.Then,they are respectively composited with other semiconductor photocatalysts,and expanding light absorption range,improving carrier separation efficiency and constructing a non-noble metal cocatalyst system were employed to enhance the photocatalytic performance of the catalyst.The main research contents are as follows:（1）Hydrothermal method was used to synthesize high-exposure{010}TiO₂ and{010}TiO₂ fiber with ordered assembling was obtained by electrospinning.Subsequently,using melamine as a precursor,g-C₃N₄ was deposited on the oriented{010}TiO₂ fibers by CVD.The photocatalytic water splitting activity of the obtained composite photocatalyst CN/oriented{010}TiO₂ fiber was up to 190%higher than that of{010}TiO₂ nanobelt,and110%higher than oriented{010}TiO₂ fibers.Combined with various characterizations,the increased activity of the catalyst is attributed to several points.Firstly,the structure of oriented fiber promotes the migration of electrons.Then,the introduction of g-C₃N₄ extends the light absorption range.Another,the construction of heterojunctions promotes transfer and separation of photogenerated carriers.（2）Oriented{010}TiO₂fiber was combined with MoSe₂to construct a non-precious metal photocatalyst MoSe₂/oriented{010}TiO₂fiber.In the absence of noble metal loading,the activity of water splitting can reach 4.1 mmol/（g·h）,which is 5.8 times higher than MoSe₂and 12.6 times higher than that of oriented{010}TiO₂ fiber.The reason for the improvement of photocatalytic activity is speculated:on the one hand,MoSe₂ nanoparticles are evenly distributed on the surface of the TiO₂ fiber,which effectively avoids the accumulation of particles and exposes more sites.On the other hand,the introduction of MoSe₂ makes light absorption range extend to the infrared light region.In addition,MoSe₂ acts as a cocatalyst to form a heterojunction with TiO₂,which promotes the separation of photo-generated charges.Thus,the performance of photocatalytic hydrogen production can be significantly improved.