Fluorescein-sensitized Au/g-C3N4 nanocomposite for enhanced photocatalytic hydrogen evolution under visible light
Fluorescein-sensitized Au/g-C3N4 nanocomposite for enhanced photocatalytic hydrogen evolution under visible light
复制标题
荧光素敏化 Au/g-C3N4 纳米复合材料可增强可见光下的光催化析氢
DOI：
10.1016/j.materresbull.2018.02.056
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发表时间：
2018-06-01
影响因子：
5.4
通讯作者：
Huang, Jian-Hua
中科院分区：
文献类型：
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作者：
Qian, Xiao-Bing;Peng, Wen;Huang, Jian-Hua
Au/g-C3N4复合材料是通过g-C3N4质子化、静电吸附AuCl4-、化学还原制备的。通过透射电镜（TEM）测量，证实了g-C3N4表面沉积了平均直径为4.1 nm的金纳米颗粒。与纯g-C3N4相比，Au/g-C3N4复合材料在三乙醇胺作为牺牲电子供体存在下的可见光（λ > 420 nm）光催化活性显著提高。值得注意的是，在光催化反应体系中加入荧光素，H-2的产率提高了22倍以上。在荧光素存在下，它比质子化g-C3N4高25倍以上。基于我们的实验结果，提出了荧光素敏化Au/g-C3N4纳米复合材料光催化H-2演化的机理。光致发光光谱和瞬态光电流响应支持了光生电子在光激发荧光素分子、g-C3N4和Au之间的有效转移。
Au/g-C3N4 composite is prepared through protonation of g-C3N4, followed by electrostatic adsorption of AuCl4- and subsequent chemical reduction. The homogeneous deposition of Au nanoparticles with an average diameter of 4.1 nm on g-C3N4 is confirmed by TEM measurement. Compared with pure g-C3N4, Au/g-C3N4 composite exhibits a significant improvement in the photocatalytic activity for H-2 production from water in the presence of triethanolamine as sacrificial electron donor under visible light irradiation (lambda > 420 nm). Significantly, the rate of H-2 production increases more than 22 times by adding fluorescein in the photocatalytic reaction system. It is more than 25 times higher than that of protonated g-C3N4 in the presence of fluorescein. Based on our experimental results, the mechanism of photocatalytic activity for H-2 evolution over fluorescein-sensitized Au/g-C3N4 nanocomposite is accordingly proposed. The highly-improved performance is ascribed to the efficient transfer of photo-generated electrons among photo-excited fluorescein molecule, g-C3N4 and Au, which is supported by photoluminescence spectra and transient photocurrent responses.