Facile synthesis of g-C3N4 nanosheets anchored with AgCl and CDs and its efficient activity in reduction of Cr(VI)

Heavy metal pollutants such as Cr(VI), due to acute toxicity, have been proved to causehazards to most of the organisms [1]. Semiconductor-based photocatalysis has attracted muchmore consideration, owing to potential utilization in water purification. For this purpose, g-C3N4was introduced as semiconductor with narrow band gap energy. However, due to itsshortcomings including smaller specific surface area, it was prepared as nanosheets of g-C3N4 (g-C3N4-NS) [2, 3]. In addition, to retardation of the electron–hole pairs from recombination, carbondots (CDs) are deposited over the g-C3N4-NS photocatalyst [3]. In this work, we focused onintegration of AgCl with g-C3N4-NS/CDs nanocomposite. The superior visible-lightphotoactivity of the g-C3N4-NS/CDs/AgCl (30%) photocatalyst was observed in photoreductionof Cr(VI) to Cr(III). Interestingly, the reduction rate constant over the ternary nanocompositewas 15.3 times premier than the g-C3N4 photocatalyst. Therefore, it was concluded thatsignificantly improved photocatalytic performance of the fabricated photocatalyst can beattributed to the impressive light harvesting capability in visible range and low recombinationrate for the e-/h+ pairs. (a) HRTEM image of the g-C3N4-NS/CDs/AgCl (30%) nanocomposite. (b) Photocatalytic reduction of Cr (VI) overthe g-C3N4, g-C3N4-NS, g-C3N4-NS/CDs, and g-C3N4-NS/CDs/AgCl (30%) samples under visible light.

Keywords:

g-C3N4-NS/CDs/AgCl , Reduction of Cr(VI) , Visible-Light Photocatalyst