构建Z型C-TiO_(2)/Pt/g-C_(3)N_(4)催化剂及其催化性能研究

Construction and photocatalytic performance ofZ-scheme C-TiO_(2)/Pt/g-C_(3)N_(4) photocatalyst

以尿素为前驱体,利用热缩聚法合成g-C_(3)N_(4)纳米片,再先后利用热还原法和水热法负载Pt纳米颗粒及C-TiO_(2)纳米颗粒,由此成功制备出Z型C-TiO_(2)/Pt/g-C_(3)N_(4)光催化剂。采用多种表征手段对其形貌、结构及光学性质进行了分析,并评估了其在可见光下降解甲基橙和盐酸四环素的性能。研究结果表明,该光催化剂对降解污染物表现出优异的性能。这主要归功于较强的可见光吸收能力、较高的光生电子-空穴对分离效率以及光生电子的强还原性、光生空穴的强氧化性。为了进一步探讨其光催化机理,对C-TiO_(2)/Pt/g-C_(3)N_(4)催化剂进行ESR测试。结果表明,在光催化过程中,具有强氧化性的·OH和·O_(2)^(-)都起到了重要的作用。

The g-C_(3)N_(4) nanosheet was synthesized by thermal condensation method,using urea as precursor.Then,the Pt nanoparticles and the C-TiO_(2) nanoparticles were growth on the surface of the g-C_(3)N_(4) by thermal reduction method and hydrothermal method successively.Thus,Z-scheme C-TiO_(2)/Pt/g-C_(3)N_(4) photocatalyst was prepared successfully.Its morphology,structure and optical properties were analyzed by a variety of characterization methods,its photocatalytic degradation properties of MO and TC in visible light were also evaluated.The results showed that the photocatalyst exhibited excellent degradation performance for these two kinds of pollutants,which was mainly attributed to the strong absorption ability of visible light,the high separation efficiency of photogenerated electron-hole pairs,the strong reducibility of photogenerated electrons and the strong oxidation of photogenerated holes.In order to further explore the photocatalytic mechanism,ESR test was conducted on the C-TiO_(2)/Pt/g-C_(3)N_(4) photocatalyst.The result showed that·OH and·O_(2)^(-) with strong oxidation played an important role in the photocatalytic process.