Studies On Preparation Of Sulfide Solid Solution Sensitized TiO₂Nanotube Arrays And Their Performance Of Photoelectrocatalytic Hydrogen Production

Hydrogen energy because of its abundant and cheap raw materials, easy to store and transport, no pollution to the environment, is generally regarded as the most ideal clean energy. Using of free and unlimited solar energy by photoelectrochemical water splitting is considered as one of the most promising hydrogen production method. TiO2as an important semiconductor photoelectrocatalytic materials has a variety of morphologies. Compared with the other TiO2morphologies, TiO2nanotubes (TiO2NTs) has larger specific surface area and stronger absorption ability. Furthermore, nanotubes perpendicular to the conductive titanium substrate can provide a unidirectional electronic channel for the transmission of photogenerated electrons, which can greatly improve the photoelectrocatalytic performance of TiO2.So it as the photoanode can effectively enhance the photoelectrocatalyticdecomposition of water into hydrogen. The TiO2nanotube array film used in the field of photoelectrocatalytic hydrogen production has the following advantages:(1)Titanium oxide films were grown in-situ on titanium foil to solve the complexsive preparation of traditional photoelectrocatalytic anodic and this method is of high reliability;(2)TiO2nanotube has greater specific surface area than traditional titanium oxide films and its quantum efficiency is high;(3) the nanotube’s special structure owns so strong adsorption capacity that it can absorb more light sensitizer, so as to solve the drawbacks of TiO2cannot use visible light. Therefore, from the point of application, research of photocatalytic decomposition of water into hydrogen is very meaningful. The main work of this paper includes the following two aspects:1. TiO2NTs was prepared by anodic oxidation method, CdxZn1-xS was loaded on TiO2NTs by SILAR method, and the factors affecting the deposition of CdxZn1-xS are analyzed. The catalysts were characterized by SEM, STEM, XRD and other techniques. SEM analysis showed that the prepared TiO2NTs own highly ordered and uniform morphology. STEM analysis results showed that the elements in CdxZn1-xS were distributed uniformly in the TiO2NTs, indicating the formation of solid solution. Uv-vis analysis showed that after doping Zn in CdS the catalyst emerged the blue shift of absorption edge, and the blue shift expanded with the Zn content increasing, which proved that the CdxZn1-xS solid solution existed. In a series of prepared CdxZn1-xS@TiO2NTs, photoelectrochemical properties of Cdo.gZno.2S@Ti02NTs were on top. Under100mW/cm2light intensity, the visible light photocurrent reached 7mA/cm2, double that of CdS@TiO2NTs, and hydrogen production performance was up to150μ mol/h,4.3times as much as CdS@TiO2NTs.2. TiO2NTs was prepared by anodic oxidation method, CdxMn1-xS was loaded at TiO2NTs by SILAR method, and the factors affecting the deposition of CdxMn1-xS were analyzed. The catalysts were characterized by SEM, STEM, XRD and other techniques. SEM analysis showed that the prepared TiO2NTs owned highly ordered and uniform morphology. STEM analysis results showed that the elements in CdxMn1-xS were distributed uniformly in the TiO2NTs, indicating the formation of solid solution. Uv-vis analysis showed that after doping Mn in CdS, the catalyst emerged the blue shift of absorption edge, and the blue shift enlarged with the Mn content increasing, which proved the existence of CdxMn1-xS solid solution. The photoelectrochemical properties and hydrogen production of prepared catalyst under visible light were studied by electrochemical workstation. We found that the sensitization characteristic of CdxMn1-xS were the same as that of CdxZn1-xS. After Mn doping into CdS to form CdxMn1-xS solid solution, the CdxMn1-xS@TiO2NTs exhibited better photoelectrocatalytic properties and hydrogen production than CdS@TiO2NTs. When the x value was0.8, the catalyst (Cd0.8Mn0.2S@TiO2NTs) exhibited best activity.