| With the rapid development of modern industry and the acceleration of urbanization,atmospheric pollutants are becoming more and more serious.Carbon monoxide(CO)is one of the main components of atmospheric pollutants.Compared with other harmful gases,the colorless and odorless physical properties of CO make its danger and seriousness often overlooked.Therefore,it is particularly important to develop methods that can effectively alleviate the problem of CO pollution.Solar-driven photocatalytic CO oxidation is a green and sustainable solution due to the merits of environmental protection and no secondary pollution,not require high temperature and high pressure,etc.,which reduces a lot of energy consumption.Meanwhile,the equipment used in photocatalytic technology is simple and flexible.However,the current photocatalytic activity of CO oxidation still moderate.Therefore,it is of great significance to rational design and fabricate efficient photocatalyst for CO oxidation.Titanium phosphate(Ti(HPO4)2,abbreviated as TiP)has been a promising environmentally friendly photocatalysts due to the porous structure,benign skeleton structure stability,excellent chemical stability and acid and alkali resistance.It is a feasible strategy to construct Z-scheme heterojunction by combining a visible-light responsive reductive semiconductor with TiP for efficient photocatalytic CO oxidation.However,the current photocatalytic performance for CO oxidation still moderate,which mainly due to the the sluggish charge separation,confined light responsive range and lack of effective active sites for O2 activation.Based on the above three key scientific questions to be addressed,the following research work was carried out in this thesis.Firstly,a Z-scheme heterojunction of g-C3N4/TiP(CN/TiP)was prepared by a wet chemical method on the basis of the fabricated two-dimensional TiP nanosheet with large specific surface area and hierarchical pore structure,then modifying with δ-MnO2(MO)on the surface of CN,in which the optimized 0.4MO-10CN/TiP catalyst exhibits a CO conversion rate of 87.0%within 60 min.The improvement of photocatalytic performance is mainly attributed to the enhanced interfacial Z-scheme charge transfer ans separation,the inhibited type-Ⅱ charge transfer pathway,and the greatly improved O2 adsorption and activation.Secondly,a Z-scheme heterojunction of FePc/TiP was fabricated by a wet chemical method,then constructing the FePc/Ag/TiP nanocomposite via interfacial modulated by ultrafine Ag nanoparticles,in which the optimized 4FePc/1.5Ag/TiP catalyst exhibits a CO conversion rate of 89.9%within 40 min.The improvement of photocatalytic performance is mainly attributed to Ag-modified could induce the electrons of TiP spontaneously move to the interface and offer a driving force for the directed charge transfer to FePc.The interactions between Ag and the N-atom of the FePc ligand could induce controllable assembly of FePc with highly dispersed,which is increase its loading amount while maintaining the optimum thickness and significant promoted Z-scheme charge transfer and separation.At the same time,abundant Fe-N4 active sites exposed effectively activate O2,which cooperative improves the photocatalytic activities performance of CO oxidation.Thirdly,a Z-scheme heterojunction of FePc/TiP was regulating constructed via functional graphene(G)by wet chemistry method.The photocatalytic CO oxidation performance of FePc/TiP heterojunction is significantly improved after introduced the G,in which the optimized 3FePc/1.5G/TiP catalyst exhibits a CO conversion rate of 80.0%within 40 min.The improves of photocatalytic performance are mainly attributed to the controllable assembly of FePc on TiP NS via the modified G,which increased the modification loading amount of FePc on the TiP surface.At the same time,G-modified could facilitate the interfacial charge transfer between FePc and TiP and subsequently increase the photocatalytic CO oxidation performance. |
