| Environmental protection and energy crisis are hot issues in today's society,and photocatalytic technology is considered as one of the important ways to effectively alleviate the above problems.up to now,There are many kinds of photocatalysts,and the alkali niobates and tantalates are representative.Niobates are important and promising photocatalysts for environmental remediation and energy applications due to their non-toxic,simple structures and easy to adjust.LiNb3O8 photocatalyst has attracted much attention due to its low cost,good stability,effective degradation of organic matter,and excellent photocatalytic hydrogen evolution capacity.In this paper,LiNb3O8 photocatalyst was prepared by a hydrothermal method assisting sintering process.Composites with one-dimensional molybdenum disulfide nanorods were also prepared by the secondary hydrothermal method.Their morphology,structure,growth mechanism,photocatalytic performance and reaction mechanism were studied.The specific results are as follows:1)Using Li OH·H2O and Nb2O5 raw materials,the LiNb3O8 photocatalyst with hollow structure was synthesized by the hydrothermal method assisting sintering process.Pure LiNb3O8 photocatalysts were obtained through calcining at 700,800,900 and 1000?with Li/Nb=8:1,Compared to the traditional solid phase method,it is easier to obtain LiNb3O8 materials with high purity and good crystallization by this method.The materials calcined at different temperatures exhibited good photocatalytic degradation of MB under ultraviolet irradiation,In particular,samples calcined at 700?(LNO700)degraded 83%MB in3h.The photodegradation rate of LNO700 is the fastest,It can be attributed to the hollow structure formed during its calcination,which results in large specific surface area and more active sites.The cyclic adsorption and photodegradation tests proved that LiNb3O8 material is stable and can be used for many times.2)Mo S2 nanorods/LiNb3O8 composite photocatalytic materials were synthesized by hydrothermal method.It was found that Mo S2 with different loads could effectively improve the photocatalytic hydrogen production performance of LNO.3)Further study revealed that a heterogeneous structure with one-dimensional Mo S2 nanorods as auxiliary catalyst was formed on the LNO photocatalyst.1D Mo S2 nanorods grew directly at the junction of LNO particles.This heterostructure is beneficial to charge separation and transfer,which improves the photocatalytic hydrogen evolution performance of LNO.When the loading capacity of one-dimensional Mo S2 nanorods is 1wt%,the hydrogen evolution efficiency is the highest,which is 3 times faster than that of pure LNO,and even better than that of heterostructure with 2D Mo S2 nanosheets co-catalyst.The cyclic hydrogen production performance test of 1wt%Mo S2 nanorods/LiNb3O8 photocatalyst showed stable performance and almost no reduction in efficiency,which also proved that one-dimensional Mo S2 nanorods were an efficient and promising photocatalytic heterostructure auxiliary catalyst. |
PDF Full Text Request