摘要利用太阳能分解水制氢，实现太阳能到化学能的一步转化，是未来最理想的 制氢技术之一，在解决能源短缺方面具有重要的应用前景。石墨相氮化碳具有优 异的化学稳定性和特殊的光电结构性质，已经被广泛研究作为一种稳定的非金属 可见光分解水制氢催化剂。然而，基于氮化碳本身聚合物的材料特性，存在激子 结合能高、光生载流子易复合等问题，导致光解水产氢效率偏低，目前的研究过 程中通常需要贵金属助催化剂的应用来提高产氢效率。然而贵金属的利用严重制 约了其在光催化领域的实际应用。83166
本文采用廉价易得的尿素为前驱体，直接高温煅烧法合成 C3N4 粉末，然后 采用乙醇超声剥离的方法将 C3N4 制备成纳米片。利用溶剂热法合成六方晶相的 MoS2 纳米片。混合沉积法将 MoS2 与 C3N4 纳米片进行复合，制备出杂化复合光 催化材料。运用扫描电镜（SEM）、X 射线衍射（XRD）、X 射线光电子能谱
（XPS）、光致发光光谱（PL）等分析了材料的形貌、晶相、结构等特征，以可 见光催化分解水制氢来评价其光催化性能。并考察了 MoS2 复合含量、复合催化 剂的制备方法，以及 Pt 助催化剂的参与对光催化活性的影响。探讨光催化产氢 性能的影响因素与反应机理。
本论文的创新性及主要结论：利用 C3N4 与 MoS2 类似层状结构的特性，制 备出二维层状复合材料，并以 MoS2 作为助催化剂取代 Pt，显著提高了 C3N4 的 可见光催化分解水制氢的性能。此复合催化剂之间形成优异的异质结构，促进了 广生电荷的分离和传输。当 MoS2 与 C3N4 的质量比为 5%时，复合催化剂的产氢 速率最高。
毕业论文关键词：C3N4；MoS2；复合催化剂；光催化；产氢
Abstract Generation of H2 via sunlight-driven water splitting to convert solar energy into chemical energy in one step, is regarded as one of the most ideal pathways for the production of hydrogen in the future, which can greatly to addressing the serious energy problems。 Graphitic carbon nitride (C3N4) has been widely used as a stable and metal-free photocatalyst for the visible-light-driven water splitting for hygrogen, owing to its excellent chemical inertness and unique opto-electronic propeties。 Nevertheless, due to the intrinsic nature as a π-conjugated polymer, the photocatalytic activity for hydrogen of pristine C3N4 is restricted by the high exciton binding energy and easy charge recombination。 Rencently, nobel metal as co-catalyst is uaually used in C3N4 to improve H2 evolution rato。 But the utilization of nobel metal greatly inhibiting its potential applications in photocatalytic fields。
Herein, via the use of cheap urea as precursor, C3N4 power was synthesized through direct calcination method，then C3N4 nanosheet was prepared from ultrasonic exfoliation in ethanol。 Hexagonal MoS2 nanosheet was synthesized from solvothermol route。 Hybrid composition of C3N4/MoS2 was obtained from mixture deposition of
C3N4 and MoS2 nanosheet。 The morphology, crystalline phases, and structure of samples were characterized by Scanning electron microscopey (SEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS),and Photo-luminescence spectra (PL)。 The photocatalytic performance of samples were evaluated through hydrogen generation from water splitting under visible light irradiation。 Moreover, we surveyed the effect to potocatalytic activity of concentration of MoS2, preparation method for catalysts and the participation of Pt co-catalyst。 The influence factors and mechanism of the photocatalytic was investigated。
The innovative aspects and main conclusions of this study include: 2D layer compozation materials were prepared by means of the similar layer structure of C3N4 and MoS2。 Also, MoS2 could be used as co-catalyst to replace Pt to enhance the photocatalytic H2 evolution performance from water under visible light。 The well heterostructure formed between C3N4 and MoS2 much improve the separation and transmission of light-induced charge。 The hightest H2 ratio was obtained on catalyst in which the mass ration of MoS2 to C3N4 is 5%。 C3N4/MoS2复合光催化剂的制备及其性能研究:http://www.youerw.com/huaxue/lunwen_97886.html