Design Of Photocatalytic Water Splitting Materials Based On TMT And Study On Hydrogen Evolution Performance

Faced with excessive consumption of fossil energy and growing energy demand,the development of sustainable energy plays a vital role.Using photocatalytic technology to convert solar energy into chemical energy is an effective way to alleviate the energy shortage problem.Hydrogen has the characteristics of high energy density and environmental friendliness,so storing solar energy with hydrogen as an energy carrier is considered to be an ideal photo-chemical energy conversion method.At present,the single photocatalytic material generally has the disadvantage of low reaction rate,and it is difficult to achieve efficient conversion of solar energy.The preparation of highly active semiconductor photocatalyst is the key to its further development.This thesis focuses on the photocatalytic material metal-organic copolymer Cd₃?C₃N₃S₃?₂[abbreviated as Cd₃?TMT?₂]and its derivative CdS as the matrix to carry out research.?1?Cd₃?TMT?₂/g-C₃N₄ heterojunction photocatalyst was constructed by one-step solvothermal method.Characterization by XRD and XPS proved the successful preparation of Cd₃?TMT?₂/g-C₃N₄?x%?composite material.With the addition of 1wt%Pt as a co-catalyst and the content of g-C₃N₄ nanosheets being 10%,the best photocatalytic performance for hydrogen production from water decomposition was obtained.This may be due to the introduction of g-C₃N₄ nanosheets,which broadened the light absorption range and improved the interface charge transfer,thereby enhancing the catalytic activity under visible light irradiation.?2?Ni-salt was introduced into the metal-organic copolymer Cd₃?TMT?₂ by in-situ precipitation method of high temperature heat treatment to prepare CdS@Ni₂P?x%?composite photocatalyst.The successful preparation of CdS@Ni₂P?x%?composite material was proved by XRD and TEM technologies.The experiment of photocatalytic decomposition of hydrogen in water shows that CdS@Ni₂P?x%?has better catalytic performance than pure CdS.When the amount of non-noble metal promoter Ni₂P is 3%,the activity of hydrogen production reaches the maximum.With high chemical stability.These may be because the good interfacial contact between the co-catalyst Ni₂P and CdS provides more transmission paths for photogenerated electrons,thereby improving the photocharge separation efficiency and the photocatalytic activity.?3?CdS@WS₂?x%?composite photocatalyst was synthesized by in-situ precipitation method.When the amount of co-catalyst WS₂ coating was 1%,the sample showed the best photocatalytic activity for hydrogen production from water decomposition,and the stability test showed that the photocatalyst was highly stable.This may be attributed to the fact that the co-catalyst WS₂ coats the surface of CdS,which enhances the close contact between the interfaces and enables the rapid transfer of electrons to WS₂,thereby inhibiting the reorganization of CdS electron-hole pairs.