In the present investigation, ternary nanocomposite of reduced graphene oxide rGO, Nickel sulphde (NiS) and gold nano cube (rGO/NiS/AuNCs) has been synthesized by adopting a facile single step hydrothermal method. The electrochemical interfacial property of the composite materials is obtained from cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The crystal structure, surface morphology and elemental composition of the rGO/NiS/AuNCs ternary nanocomposite are characterized using XRD, SEM and EDX measurements, the characterization of the materials using such techniques have shown the formation of flower shaped NiS and Au in the form of AuNCs, effective formation of composite has been evident from the microscopic and spectroscopic measurements. The square wave voltammetry technique is employed to the determination of Cr(VI) in 0.1 M acetate buffer solution at the optimized pH 5. The influence of various electrochemical parameters affecting the stripping voltammetry are investigated and optimized. Under optimal condition, the limit of detection (LOD) in the present method is found to be 0.09 µgL⁻¹ at the accumulation potential of -0.5V for the duration of 30s. The rGO/NiS/AuNCs ternary nano composite modified electrode showed good stability and high sensitivity towards the detection of Cr(VI) with low response time. The developed method has been applied for the detection of Cr(VI) in environmental samples.

在本研究中，已采用一种简便的单步水热法合成了氧化石墨烯rGO，硫化镍（NiS）和金纳米立方（rGO / NiS / AuNCs）的三元纳米复合材料。复合材料的电化学界面特性是通过循环伏安法和电化学阻抗谱（EIS）获得的。rGO / NiS / AuNCs三元纳米复合材料的晶体结构，表面形貌和元素组成使用XRD，SEM和EDX测量进行了表征，使用此类技术对材料进行的表征表明，花状NiS和Au以下列形式形成： AuNCs，复合物的有效形成已经从显微镜和光谱学测量中明显看出。方波伏安法用于测定0中的Cr（VI）。在最适pH 5下使用1 M乙酸盐缓冲溶液。研究并优化了各种电化学参数对溶出伏安法的影响。在最佳条件下，发现本方法的检出限（LOD）为0.09 µgL^-1在-0.5V的累积电势下持续30s。rGO / NiS / AuNCs三元纳米复合修饰电极对Cr（VI）的检测具有良好的稳定性和高灵敏度，且响应时间短。所开发的方法已用于环境样品中Cr（VI）的检测。