Green synthesis of lignin nanorods/g-C3N4 nanocomposite materials for efficient photocatalytic degradation of triclosan in environmental water

Abstract

Triclosan (TCS) is a common anti-microbial ingredient in pharmaceutical and personal care products. The usage of TCS was banned by the United States Food and Drug Administration (in 2016) due to its potential health risks. However, TCS has been frequently detected in the aquatic environment. Therefore, it is vital to design low-cost and highly efficient photocatalysts to enhance TCS’s photocatalytic degradation in wastewater treatment to eliminate its toxicity to environmental health. In this study, we developed a highly efficient catalyst by incorporating lignin nanorods (LNRs) into graphitic carbon nitride (GCN) nanomaterials as green LNRs/GCN-based nanocomposite photocatalysts for the effective degradation of TCS in waters. LNRs/GCN nanosheets (NSs) and LNRs/GCN-NRs based nanocomposite materials were prepared using a simple wet-impregnation method. The surface morphology and optical properties of as-synthesized materials were well-characterized using FE-SEM, XRD, XPS, and UV-DRS. The photocatalyst (LNRs/GCN-NRs) material showed maximum TCS degradation efficiency of 99.9% and a high rate constant of 0.0661 min−1 under pH-10 with crucial reactive spices (OH and O2−), and excellent cycling performance (over five cycles) within 90 min of UV-light illumination. LNRs/GCN-NRs nanocomposite indicated enhanced photocatalytic performances for TCS degradation due to its strong synergistic effect between LNRs and GCN-NRs as bifunctional catalyst substrate morphology with efficient bandgap energy and accessible active sites compared to LNRs/GCN-NSs. Therefore, LNRs/GCN-NRs nanocomposite was observed to be a highly-active, low-cost, stable, eco-friendly, and efficient photocatalyst for complete degradation of TCS under UV-light irradiation.