Abstract：
Graphitic carbon nitride mutated with metal nanoparticles has captivated great interest as an effective fluorescent sensor for the detection of harmful ions present in water. In the present work, bulk-gCN was synthesized using melamine as precursor, and further Au-gCN nanocomposite were fabricated via in-situ direct reduction deposition method. The structural, morphological, compositional, stability and optical properties of bulk gCN and Au-gCN nanocomposite were examined using various scattering and spectroscopic techniques such as HRTEM, XPS, XRD and SEM. The synthesized bulk gCN straggles during selectivity studies with different cations and anions because of its uneven surface morphology, however in Au-gCN gold nanoparticles are uniformly distributed on the gCN sheets which results in its enhanced selectivity over bulk gCN. This leads to the fabrication of an optical sensor for Fe3+ and Cr2O72- ions with limit of detection of 4.62 and 2.77 μM, respectively. The sensing of Fe3+ ions corresponds to the photoinduced electron transfer (PET) mechanism, while the detection of chromate species is associated with an inner filter effect (IFE). The practical applicability of the sensor was also evaluated for different environmental water samples. The high stability, sensitivity, and specificity of Au-gCN nanocomposite make it a potential fluorescent probe for Fe3+ and Cr2O72- ions in water samples.
摘要：
用金属纳米颗粒突变的石墨氮化碳作为用于检测水中存在的有害离子的有效荧光传感器引起了极大的兴趣。在目前的工作中,以三聚氰胺为前体合成了bulk-gCN，并进一步通过原位直接还原沉积法制备了Au-gCN纳米复合材料。结构,形态学,组成,使用各种散射和光谱技术（如HRTEM）检查了块状gCN和Au-gCN纳米复合材料的稳定性和光学性能，XPS,XRD和SEM。由于其不均匀的表面形态，在对不同阳离子和阴离子的选择性研究中，合成的块状gCN散乱。然而,在Au-gCN中,金纳米颗粒均匀分布在gCN片上,这导致其相对于本体gCN的选择性增强。这导致了Fe3和Cr2离子的光学传感器的制造，检测极限为4.62和2.77μM，分别。Fe3+离子的传感对应于光诱导电子转移（PET）机制，而铬酸盐种类的检测与内部过滤效应（IFE）有关。还评估了该传感器对不同环境水样的实际适用性。稳定性高,灵敏度,Au-gCN纳米复合材料的特异性使其成为水样中Fe3+和Cr2离子的潜在荧光探针。
