Synthesis Of Molybdenum Disulfide/Black Titanium Dioxide And Its Photocatalytic Hydrogen Production Performance Study

Since Fujishima and Honda found that semiconductor photocatalytic materials could be used to split water to produce hydrogen,the hydrogen production technology has attracted more and more attention.At present,TiO₂ has been widely investigated for splitting water to produce hydrogen,pollutant degradation and dye-sensitized solar cells due to stong oxidizing power,good chemical and physical stability,nontoxicity and low cost.Unfortunately,TiO₂ has two significant disadvantages which limit the application of photocatalytic hydrogen production.The one is its wide band gap?3.2 eV?and the other is the rapid recombination of photogenerated electron-hole pairs.To solve the above problems,MBT/MoS₂/MBT photocatalyst and N-TiO_2-x@MoS₂ photocatalyst with 3D microstructures were designed through two different synthetic routes in this paper,which included the systems of Ti³⁺ self-doping or co-doping and coupling with norrow band gap semiconductor material MoS₂?1.8 eV?.In addition,the crystal phase structure,elements,morphology and optical properties of these samples were characterized by XRD,Raman,BET,XPS,SEM,TEM and UV-Vis.Moreover,we had evaluated its photocatalytic performance with the help of hydrogen production and pollutant degradation under visible-light irradiation.In the end,the relative reaction Imechanism was also summaried and analysised.The main research results of this paper as follows:?1?The 3D sandwich-like MBT/MoS₂/MBT photocatalyst was successfully fabricated using a facile mechanochemical process and in situ solid-state chemical reduction method with commercial TiO₂ and MoS₂ as raw materials.Through the performance tests,we found that the MBT/MoS₂/MBT exhibited the best photocatalyticactivity when the MoS₂ rate was 6%.Under the visible-light irradiation,the hydrogen production rate and the degradation rate of MO were as high as 0.56 mmol-1g-1 and 89.86%.?2?The 3D flower-like N-TiO_2-x@MoS₂ photocatalyst was successfully fabricated using a typical hydrothermal recation and in situ solid-state chemical reduction method.Through the performance tests,we found that the N-TiO_2-x@MoS₂ exhibited the best photocatalytic activity when the temperature of hydrothermal recation was 200 ?,the recation time was 18 h and the mole rate of N-TiO₂ and MoS₂ was 3:1.Under the visible-light irradiation,the hydrogen production rate and the degradation rate of MO were as high as 1.882 mmol-1g-1 and 91.8%.?3?According to the characterization and performance tests of these two photocatalysts,we proposed a reaction mechanism.The enhanced photocatalysis performance could be attributed to the introduction of Ti³⁺ or N and Ti³⁺ co-doping system which could be contributed to effectively narrow the band gap.Meanwhile,the heterojunction between MoS₂ and Ti02 and the activity sites of MoS₂ could effectively restrain the recombination of photogenerated electron-hole pairs and accelerate the electron transfer to enhance the photocatalytic activity.