Preparation Of Sulfide Solid Solution Coated On TiO₂Films And The Photo Catalytic For H₂production

In this paper, in order to solve the difficulties for the separation and the recovery ofthe power catalysts and the narrow range of the spectrum for TiO₂particles, the plasmaelectrolytic oxidation and anodic oxidation methods were adopted to prepare TiO₂filmsand TiO₂nanotubes on pure titanium, respectively, and hydrothermal method was usedto load sulfide solid solution on the surface of TiO₂films and TiO₂nanotubes. Thephase topographies and the composition and the absorption spectrum of the catalystwere investigated, the catalytic property of TiO₂films and TiO₂nanotubes loaded withthe sulfide solid solution was evaluated according to the amount of hydrogen productionwithin4h in the solution with0.1mol·L^-1Na2S and0.02mol· L^-1Na₂SO₃as sacrificialagent, using external500W xenon lamp.The film prepared by plasma electrolytic oxidation method is porous andcomposed of anatase and rutule TiO₂, among them anatase TiO₂is the main crystalline.After the hydrothermal treatment, the sort of ZnS-In2S3was successfully loaded on theTiO₂films. With the increase of the loaded elements in the solid solution, the catalyticperformance of the catalysts loaded with sulfide and sulfide solid solution was increased.The absorption spectrum of TiO₂films loaded with ZnS blue-shifts, while theabsorption spectrum of TiO₂films loaded with the binary and ternary sulfide solidsolution red-shifts. As for TiO₂film loaded with Ag2S-CuS-ZnS-In2S3, the absorptionedge clearly red-shifts along with the increase of Ag element, the absorption intensity isalso increased as well. When the amount of AgNO3in the solution is0.0275g duringthe hydrothermal treatment, the hydrogen production rate of the catalyst presents18.90μmol·h^-1, which is1.52times than the blank tests. As for TiO₂films loaded withZnS-CdS, the absorption edge of the absorption spectrum red-shifts, when the ratio ofZn: Cd=1:1, the redshift of the catalyst is the largest, the hydrogen production is themaximum with the value of28.75μmol· h^-1,2.31times higher than the blank tests.TiO₂nanotubes array on pure titanium matrix was prepared by anodic oxidationmethod,with the diameter of about50nm and the length of about1μm. Calcined under400°C in the air, TiO₂nanotubes is composed of anatase and rutule TiO₂,amongthemthe latter is more than the former. Using it as the carrier, the CdS/Zn1-xCdxS/TiO₂NTswas prepared by two-step hydrothermal synthesis method. The results of photocatalytichydrogen production experiment showed that when the concentration of Cd2+was0.025mmol, the nanotube presents the higher photocatalytic activity of hydrogen, with thehydrogen production rate of33.22μmol/h.