Removal of Chromium from Wastewater Through the Formation of a Layered Double Hydroxide Material for Further Use as a Photocatalyst

Abstract

Chromium (Cr)-containing contaminated wastewater has posed a serious threat to environmental safety and human health. The traditional reduction-precipitation method for removing Cr is known to exhibit difficulties, such as slow reaction rates and poor resource utilization. Herein, we demonstrated that the formation of layered double hydroxide (ZnCr-LDH) is very promising for Cr removal and recycling. Due to the bimetallic synergistic between the ions (Zn and Cr), the reaction is accelerated compared to the formation of hydroxide, promoting the process of nucleation and crystallization. This method presents the rapid formation of ZnCr-LDH within 1 min and efficient removal of Cr. The removal capacity was further increased to 183.4 mg∙g⁻¹. Similarly, the formation of ZnCr-LDH also performs well in treatment for actual wastewater. The product ZnCr-LDH is a highly efficient photocatalyst, exhibiting a degradation efficiency of 88.6% for tetracycline (TC). Thus, this proposed strategy introduces an efficient and environmentally friendly solution for wastewater treatment. By transforming waste into useful products, this work helps to promote resource recycling and reduce the demand for natural resources, thereby holding important economic and ecological value.