Synthesis And Photocatalytic Degradation Of Phosphorothioate Compounds

In recent years,organophosphorus compounds have been widely used in medicine,agriculture,materials and organic synthesis.However,phosphorothioate substances have caused a lot of environmental pollution.How to maintain our environment while maintaining its efficacy has become one of the hot topics.At present,nano-assembled photocatalytic materials have attracted a lot of attention by using visible light to degrade organic compounds.These materials can sense and capture organic pollutants in water.In this paper,the dehydrogenation coupling reaction of P（O）-H and Ar-SH compound was realized by alkali metal salt catalysis,and the phosphorothioate was degraded by M-polyoxometalates and photocatalytic material.The details are as follows:O,O-diethyl-S-（p-tolyl）phosphorothioate was prepared by direct dehydrogenation coupling of diethyl phosphite and P-toluene thiophenol with DMA as a solvent.The conditions were optimized from the reaction time and temperature,solvent,material ratio,amount of base,and catalyst.The anion[PW₁₁M（H₂O）O₃₉]^（n-m）was prepared by mixing Na₂HPO₄,Na₂WO₄?2H₂O and M（Fe,Co,Ni）nitrate solutions,and the pH was adjusted to about 4.8.Then 20 mL of tetrabutylammonium bromide was added dropwise to the above mixture under stirring at80-85°C.The formed precipitate was filtered off and recrystallized from acetonitrile to obtain the corresponding metal heteropolyacid salt.Through a series of characterization and evaluation,high-activity,high-stability,high-efficiency catalysts were selected.The ternary composites g-C₃N₄/Bi₂WO₆/WO₃ and RGO/Bi₂WO₆/WO₃ with the films g-C₃N₄ and RGO as carriers were prepared by solvothermal-calcination-hydrothermal method,respectively.After a series of characterization and evaluation,the composition,structure,morphology and catalytic performance,stability and mechanism of the catalyst were clarified.Among them,RGO is superior to g-C₃N₄ as the carrier.The reason may be that graphene has a lower Fermi level（-0.08 V vs NHE）,which causes photogenerated electrons to be limited to graphene.In the conductive network,the separation of electron-hole pairs is effectively promoted,and the photocatalytic performance of the composite material is obviously improved.