Application Of Two-dimensional Transition Metal Carbide Ti₃C₂T_x In Photocatalytic Water Splitting For Hydrogen Evolution

Energy crisis and environmental problems are the major sustainable development problems faced by mankind at present.The use of solar energy is one of the effective ways to solve these problems in the future,which has been widely concerned by scholars.Photocatalytic water splitting hydrogen evolution can convert solar energy into clean hydrogen energy,but it has never been commercialized due to cost and efficiency issues.Two-dimensional(2D)Ti3C2Tx have been applied in many fields since they were discovered because of its excellent conductivity and low cost.They also show a broad application prospect in photocatalytic water splitting hydrogen evolution.In this paper,we successfully prepare two-dimensional Ti3C2 Tx with different morphologies.Combined with different photocatalysts by different methods,we successfully construct different systems for photocatalytic water splitting hydrogen evolution.The mechanism of photocatalytic water splitting hydrogen evolution is explored with the reduced cost and the improved efficiency.The application range of2 D Ti3C2Tx is extended.The cognition of 2D Ti3C2 Tx properties is deepened.A new idea for the commercial application of photocatalytic water splitting hydrogen evolution is provided.We prepare g-C3N4/Ti3C2 Tx composite through simple mechanical method and tried to use it in photocatalytic water splitting hydrogen evolution,and successfully construct the g-C3N4/Ti3C2 Tx photocatalytic water splitting hydrogen evolution system.DFT calculations show that the-O surface termination groups reduce the Gibbs free energy of hydrogen evolution.Though the efficiency and the stability of gC3N4/Ti3C2 Tx need to be improved,it is proved that Ti3C2 Tx can be applied as a cocatalyst to realize the separation and transfer of photo-generated electrons and suppressing the recombination of photo-generated electron-hole pairs.The efficiency of photocatalytic water splitting can be improved by tuning the surface termination groups of Ti3C2 Tx.To further improve the efficiency and the stability of photocatalytic water splitting hydrogen evolution,the monolayer Ti3C2 Tx etched by in situ HF method is applied as a co-catalyst,and the selenide solid solution is combined by impregnation method as photocatalyst.The morphologies and properties of selenides are controlled by tuning the type of flux,sintering time and sintering temperature.The ratio of monolayer Ti3C2 Tx to selenide is optimized to construct an efficient photocatalytic water splitting hydrogen evolution system and improve the efficiency of hydrogen evolution.Meanwhile,the reaction mechanism of the system is considered.We prepare Ti O2/Ti3C2 Tx composite by in-situ hydrothermal oxidation method,and construct a new photocatalytic water splitting hydrogen evolution system using Eosin Y(EY)dye as a photosensitizer.The ratio of Ti O2 and Ti3C2 Tx is regulated by controlling the oxidation time.The concentration of EY is optimized to improve the efficiency of hydrogen evolution.The photocatalyst prepared by hydrothermal method in one step makes the photocatalyst more stable and the efficiency of photo-generated charge separation can be improved.EY extends the absorption range of light and improves the efficiency of photocatalytic hydrogen evolution.A new idea is provided for the application of Ti3C2 Tx in this field.To expand the application of Ti3C2 Tx in this field,we prepare Ti O2/Ti3C2 Tx composites by simple heat treatment method.A new photocatalytic water splitting hydrogen evolution system is constructed by sensitization of soluble porphyrin sodium salt.The concentration of porphyrin sodium sensitizer and the effect of different sacrifice agents on hydrogen evolution are optimized,and the reaction mechanism of the system is investigated.This study deepens the understanding of two-dimensional Ti3C2 Tx.This application of Ti3C2 Tx provides a new direction for the commercialization of photocatalytic water splitting hydrogen evolution.New photocatalytic water splitting hydrogen evolution systems are constructed,lying a foundation for the further application of Ti3C2 Tx in the field of photocatalytic water splitting hydrogen evolution.