An advanced LDH derived photocatalyst with enhanced charge separation for sustainable environmental remediation

Abstract

The discharge of highly contaminated wastewater effluent, particularly from industries such as textiles, pharmaceuticals, and tanneries, into ecology poses a crucial threat to the biosphere. Environmental protection demands wastewater treatment that eliminate hazardous industrial dyes before discharge through the use of sustainable technologies. Layered Double Hydroxides (LDHs) emerged as a 2D anionic class of clays exhibiting adjustable composition with broad surface areas and remarkable ion-exchange capabilities demonstrating them as potential photocatalysts for wastewater remediation. This research proposes a facile coprecipitation method followed by wet impregnation to develop a novel GO/TiO₂/ZnAl LDH photocatalyst to efficiently degrade dyes. 10% GO loading onto TiO₂/ZnAl LDH has demonstrated notable operational activity, which led to the effective degradation of Congo Red (CR) dye under visible light illumination. The ternary composite displayed a degradation efficiency of 91% when a catalyst dosage of 0.5 g was loaded to degrade 50 ppm of the dye solution within 5 h under visible light. The optimal addition of graphene oxide (GO) to the TiO₂/ZnAl-LDH matrix led to superior photocatalytic performance when compared with TiO₂/ZnAl-LDH, ZnAl-LDH, GO, and TiO₂ NPs. The resultant enhanced photocatalytic performance can be attributed to GO's high electrical conductivity and large surface area that leads to improved charge carrier separation and minimized electron–hole recombination. The material's structural, morphological, and optical features were analyzed using characterization techniques such as SEM, XRD, FTIR, UV-vis, Raman, and photoluminescence spectroscopy. This research introduces a verstile strategy to remediate textile industry waste water contaminated with CR utilizing a highly effective ternary photocatalyst.