A review: Engineered nanomaterials for photoreduction of Cr(VI) to Cr(III)

The effluents generated pose a threat to all life forms in nature. Chromium is one of the most toxic effluent due to its carcinogenic and cytotoxic nature. In recent decades the remediation of chromium is the biggest challenge in front of human beings. The various chromium remediation techniques are briefed. In this review, we overview recent developments on the usefulness of the nanocomposite of carbon-based, metal-doped, non-metal doped, transition metal chalcogenides, metal-organic framework, layered double hydroxides (LDHs) and MXenes for photoreduction of Cr(VI) to Cr(III) and its mechanism are also discussed. Finally, we also propose the challenges, possible directions, advantages, and restrictions for the use of photocatalysts for Cr(VI) photoreduction.