Reduced Graphene Oxide - Zinc Sulfide Composite for Solar Light Responsive Photo Current Generation and Photocatalytic 4-Nitrophenol Reduction

Solution processable Reduced Graphene Oxide - Zinc Sulfide (RGO-ZnS) composite has been synthesized by a simple single step one-pot solvothermal route. As-synthesized composite was characterized structurally and optically. The photo induced charge generation of RGO-ZnS in solid phase as well as in solution phase has been investigated under simulated solar light illumination. RGO-ZnS thin film photo detector shows an excellent photocurrent generation with a high degree of reproducibility. The photosensitivity (ratio of photo to dark current) of the detector varies linearly with the light intensity, which is advantageous to tune the optoelectronic device performance and paves the way for its application. A remarkable increase of photoreduction efficiency of RGO-ZnS compare to controlled ZnS / controlled RGO towards the reduction of 4-Nitrophenol was observed. Here RGO plays a crucial role as solid state electron mediator to separate the photoexcited electron and holes and subsequently hinders the electron-hole pair recombination probability. Which consequently increases the photocurrent generation and photocatalytic activity of the composite.