WS_(2)/TiO_(2)异质结构的制备及其模拟太阳光下的分解水性能研究

Preparation of WS_(2)/TiO_(2) Heterostructure and Its Performance of Water Decomposition Under Simulated Sunlight

二氧化钛(TiO_(2))因其合适的带隙、稳定的化学性质、耐腐蚀和绿色环保等特点作为光催化材料被广泛应用。然而,在实际应用中,因TiO_(2)存在光催化活性低、光利用率低等缺点而极大地限制了其作为光催化材料的应用前景。鉴于此引入半导体层状材料二硫化钨(WS_(2)),通过绿色、无污染的超临界流体技术成功地制备出了二维WS_(2)/TiO_(2)异质结构。以透射电镜、X射线衍射图谱与光电子射线能谱图等测试方法对WS_(2)/TiO_(2)异质结构的形貌、结构进行表征。通过紫外可见吸收光谱、线性扫描伏安曲线、光电流密度以及电化学阻抗谱等测试方法,对WS_(2)/TiO_(2)异质结构的光吸收性能及光电催化性能进行表征。结果表明,WS_(2)纳米片的引入可以明显增强体系的光吸收强度,提高了光电流密度并且降低其阻抗,使得WS_(2)/TiO_(2)异质结构展现出优异的光电化学活性。

Titanium dioxide(TiO_(2))has been widely studied as photocatalytic material due to its suitable band gap,stable chemical properties,acid and alkali corrosion resistance,and environmental protection.However,in practical applications,TiO_(2) still has shortcomings of low photocatalytic activity and low light utilization,which greatly limit its application prospectsas a photocatalytic material.In view of the above shortcomings,the semiconductor layered material tungsten disulfide(WS_(2))is introduced in this study,and two-dimensional WS_(2)/TiO_(2) heterostructures are successfully prepared by means of green and pollution-free supercritical fluid technology.The morphology and structure of WS_(2)/TiO_(2) heterostructureare characterized by transmission electron microscope,X-ray diffraction and photoelectron ray spectroscopy.The photoabsorption and photocatalytic properties of WS_(2)/TiO_(2) heterostructure are characterized by UV-visible absorption spectrum,linear scanning voltammetrycurve,photocurrent density and electrochemical impedance spectroscopy.The results show that the introduction of WS2 nanosheets can significantly enhance the light optical absorption intensity of the system,improve increase the its photocurrent density and reduce its the impedance,which makes theso that WS_(2)/TiO_(2) heterostructure show excellent photoelectrochemical activity.