Hexavalent chromium is an important inorganic industrial effluent in the water that causes serious health problems to the mankind. Photocatalytic reduction of Cr(VI) is a green technology that converts the toxic Cr(VI) to non-toxic Cr(III). In the photocatalytic reduction of Cr(VI), transition metal oxide semiconductors are mainly used as photocatalysts. This infers, for the removal of a transition metal i.e. Cr(VI), another transition metal is added in the form of photocatalyst. Hence, we explore a non-metallic, elemental photocatalyst fibrous red phosphorus (FRP), a crystalline allotrope of red phosphorus as photocatalyst for Cr(VI) reduction. FRP exhibits excellent photocatalytic activity towards Cr(VI) reduction under direct sunlight and we observed complete reduction of Cr(VI) (25 mg/L) within 40 min at pH-2.
T. K. Athira, Roshith, M., Dr. Satheesh Babu T. G., and Kumar, D. V. Ravi, “Fibrous red phosphorus as a non-metallic photocatalyst for the effective reduction of Cr(VI) under direct sunlight”, Materials Letters, vol. 283, p. 128750, 2021.