Tuning the\nStructural and Electronic Properties of\nZn–Cr LDH/GCN Heterostructure for Enhanced Photodegradation\nof Estrone in UV and Visible Light

Estrone is an emerging\ncontaminant found in waters and\nsoils all\nover the world. Conventional water treatment methods are not suitable\nfor estrone removal due to its nonpolarity and low bioavailability.\nHeterogeneous photocatalysis is a promising approach; however, pristine\nsemiconductors need optimization for efficient estrone photodegradation.\nHerein, we compared Zn–Cr LDH/GCN heterostructures obtained\nby three different synthesis methods. The influence of the GCN content\nin the heterostructure on photoactivity was also tested. The morphology,\nstructure, and electronic properties of the materials were analyzed\nand compared. The photocatalytic kinetic tests were conducted with\n1 ppm of estrone in both UV and visible light, separately. The HLDH-G50\nmaterial, obtained by the hydrothermal route and containing 50 wt\n% of GCN exhibited the highest photocatalytic efficiency. After 1\nh, 99.5% of the estrone was degraded in visible light. In UV light,\nthe pollutant concentration was below the detection limit after 0.5\nh. The superior effectiveness was caused by numerous factors such\nas high homogeneity of the formed heterostructure, lower band gap\nenergy of hydrothermal LDH, and increased photocurrent. These characteristics\nled to prolonged lifetimes of charge carriers, a wider light absorption\nrange, and uniformity of the material for predictable performance.\nThis study highlights the importance of a proper heterostructure engineering\nstrategy for acquiring highly effective photocatalysts designed for\nwater purification. In particular, this work provides innovative insight\ninto comparing different synthesis methods and their influence on\nmaterials’ properties.