Eco-friendly highly efficient BN/rGO/TiO2 nanocomposite visible-light photocatalyst for phenol mineralization

Boron nitride (BN) and reduced graphene oxide (rGO) of different loadings were composited with commercial P25 TiO2 (Ti) through the hydrothermal method. The as-prepared nanocomposites were characterized using various techniques: X-ray photoelectron spectroscopy, X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared and Raman spectroscopies, and transmission and scanning electron microscopies. It was observed that 10% and 0.1% of BN and rGO, respectively, loaded on TiO2 (10BNr0.1GOTi) resulted in the best nanocomposite in terms of phenol degradation under simulated sunlight. A 93.4% degradation of phenol was obtained within 30 min in the presence of H2O2. Finally, to ensure the safe use of BNrGOTi nanoparticles in the aquatic environment, acute zebrafish toxicity (acutoxicity) assays were studied. The 96-h acute toxicity assays using the zebrafish embryo model revealed that the LC50 for the BNrGOTi nanoparticle was 677.8 mg L−1 and the no observed effect concentration (NOEC) was 150 mg L−1. Therefore, based on the LC50 value and according to the Fish and Wildlife Service Acute Toxicity Rating Scale, BNrGOTi is categorized as a “practically not toxic” photocatalyst for water treatment.Open access funding provided by the Qatar National Library. This work was supported by the Qatar National Research Fund (QNRF, a member of the Qatar Foundation) through the National Priority Research Program Grant (NPRP) NPRP13S-0117-200095. Also, this publication was supported by Qatar University ' s internal grant IRCC-2021-015. Statements made herein are solely the responsibility of the authors

Synthesis and Optimization of a Highly Stable and Efficient BN/TiO2 Nanocomposite for Phenol Degradation: A Photocatalytic, Mechanistic and Environmental Impact Study

Different BN/TiO2 nanocomposites were prepared hydrothermally, and their ratio was optimized to get the best photocatalytic performance towards phenol degradation. They were characterized by x-ray photoelectron spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning and transmission electron microscopies coupled with energy dispersive x-ray units, BET surface area, and UV-Vis diffuse reflectance. The bandgap energy was reduced from 3.35 to 2.95 eV due to the formation of the B-O-Ti bond. This allowed the exploitation of the visible light and inhibited the TiO2 e(-)/h(+) recombination, and consequently, the photocatalytic activity of TiO2 was dramatically improved. Almost 90 % mineralization of 20 ppm phenol solution was achieved within 30 min under simulated sunlight. The as-prepared composite showed excellent stability and reusability. Mechanistic analysis indicated that O2.- and h(+) played a crucial role in phenol degradation. The nanocomposite ' s biocompatibility and environmental impact were evaluated by analyzing its potential toxicity in vivo using the zebrafish embryos. 96-hpf acute toxicity assays, including the mortality rate assay (to obtain the LC50 values) and teratogenic assays (to obtain the No Observed Effect Concentration, NOEC) was conducted. The LC50 value for BN/TiO2 was 482.5 mg L-1, and the NOEC was 100 mg L-1. Based on LC50 value and according to the Fish and Wildlife Service (FWS) acute toxicity rating scale, the photocatalyst is "practically not toxic.

Eco-friendly highly efficient BN/rGO/TiO2 nanocomposite visible-light photocatalyst for phenol mineralization

Boron nitride (BN) and reduced graphene oxide (rGO) of different loadings were composited with commercial P25 TiO2 (Ti) through the hydrothermal method. The as-prepared nanocomposites were characterized using various techniques: X-ray photoelectron spectroscopy, X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared and Raman spectroscopies, and transmission and scanning electron microscopies. It was observed that 10% and 0.1% of BN and rGO, respectively, loaded on TiO2 (10BNr0.1GOTi) resulted in the best nanocomposite in terms of phenol degradation under simulated sunlight. A 93.4% degradation of phenol was obtained within 30 min in the presence of H2O2. Finally, to ensure the safe use of BNrGOTi nanoparticles in the aquatic environment, acute zebrafish toxicity (acutoxicity) assays were studied. The 96-h acute toxicity assays using the zebrafish embryo model revealed that the LC50 for the BNrGOTi nanoparticle was 677.8 mg L−1 and the no observed effect concentration (NOEC) was 150 mg L−1. Therefore, based on the LC50 value and according to the Fish and Wildlife Service Acute Toxicity Rating Scale, BNrGOTi is categorized as a “practically not toxic” photocatalyst for water treatment.Other Information Published in: Environmental Science and Pollution Research License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s11356-021-15083-y</p