Search

Bi2Fe4O9/Ag3PO4 (BFO/APO) composites as a kind of new material were successfully prepared through the hydrothermal‐precipitation method and employed for degrading 17α‐ethynyl estradiol (EE2). Upon illumination, the total removal efficiency of EE2 reached 98.68 % and the reaction rate constant K value of 1 : 6 BFO/APO (0.05111 min−1) was respectively 7, 5 and 55 times that of BFO (0.01074 min−1), APO (0.007260 min−1) and conventional photocatalysis (9.38×10−4 min−1). The combination with BFO also effectively prevented the occurrence of APO photo corrosion reactions. According to the capture experiments,.O2−, holes and.OH are considered major or minor important respectively to the photocatalytic reaction. This work provides a new insight in construct the direct Z‐scheme photocatalyst for EE2 degradation. [ABSTRACT FROM AUTHOR]

In this study, BiOI was successfully synthesized using a hydrothermal method and then modified using hexamethyldisiloxane (HMDS) and polydimethylsiloxane (PDMS), respectively, to achieve a controllable water contact angle (WCA) for these materials. The physical and chemical properties of the modified BiOI were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FTIR) spectroscopy and water contact angle (WCA) techniques. Compared with the unmodified BiOI, HMDS- and PDMS-modified BiOI had higher photocatalytic activities for 17 α -ethinylestradiol (EE2) under visible light irradiation for 28 min after reacting in dark for 30 min. When BiOI was modified using HMDS and PDMS, the WCA increased. When the WCA of HMDS- and PDMS-modified BiOI was controlled in the range of 25.3–32.7 ∘ and 38.1–78.5 ∘ , respectively, better photocatalytic performances were achieved. When the WCA of modified BiOI was 29.7 ∘ (1.00 mL HMDS) and 47.8 ∘ (0.20 mL PDMS), the best photocatalytic performances were achieved with EE2 removal rate of 98.85% and 98.72%, respectively, however, the removal rate of the unmodified BiOI was 85.01%. The reaction rate constants of BiOI (1.00 mL HMDS) and BiOI (0.20 mL PDMS) were 2.33 and 2.15 times higher than the unmodified BiOI, respectively. The improved catalytic performances of modified BiOI could be attributed to the synergistic effect of the controlled wettability of BiOI and functional groups on the surface of photocatalysts. BiOI was modified using HMDS and PDMS, respectively, to achieve a controllable WCA for these materials. Compared with the unmodified BiOI, when the WCA of modified BiOI was 29.7∘ (1.00 mL HMDS) and 47.8∘ (0.20 mL PDMS), the best EE2 removal rates were achieved. The improved catalytic performances of modified BiOI could be attributed to the synergistic effect of the controlled wettability of BiOI and functional groups on the surface of photocatalysts. [ABSTRACT FROM AUTHOR]

Endocrine disrupting chemicals (EDCs) have adverse effects on the aquatic environment and human health as well. In this study, a ZnO/Bi 2 MoO 6 {0 1 0} composite photocatalyst was fabricated via a simple hydrothermal calcination method for the efficient and synergistic adsorption-photocatalytic degradation of an environmental endocrine disruptor, 17α-ethynylestradiol (EE2). Adjusting the pH of the synthetic procedure, selectively exposed the highly reactive {0 1 0} crystalline surface of Bi 2 MoO 6 , and the surface hydrophilicity of the material decreased, enhancing the adsorption efficiency (74.74%) of the hydrophobic EE2 molecule. Density functional theory calculations showed that the chemisorption of the EE2 molecules takes place on the Bi 2 MoO 6 {0 1 0} surface owing to the binding of hydroxyl groups. Furthermore, by incorporating energy-band-matched ZnO to form heterojunctions with Bi 2 MoO 6 {0 1 0}, the obtained composites achieved a removal rate of 90% for EE2 after 40 min of visible light catalysis. Capture experiments and electron paramagnetic resonance spectra revealed that h+ and •O 2 - were the main active species, and the catalytic mechanism followed was that of a type II reaction. This study introduced a new strategy for the modification of photocatalysts resulting in a stable change in their surface properties for enhanced pollutant removal efficiency. [Display omitted] • Bi 2 MoO 6 exposes the {0 1 0} active crystal planes causing the stable modification. • EE2 adsorption is improved by enhancement in Bi 2 MoO 6 surface hydrophobicity. • Synergistic adsorption-photocatalytic strategy improves the degradation efficiency. • ZnO/Bi 2 MoO 6 {0 1 0} composite efficiently degrades EE2 in wastewater. [ABSTRACT FROM AUTHOR]

We report a simple method to modify the surface of 1:1 AgI/BiVO 4 composites with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDS), 3-(methacryloyloxy)propyltrimethoxysilane (KH-570), and trimethylchlorosilane (TMCS). The physical and chemical properties of the photocatalysts before and after modification were characterized by XRD, XPS, SEM, FT–IR, UV–vis DRS, and water contact angle (WCA) measurements. After the modification, the WCA of the 1:1 AgI/BiVO 4 composites increased from 34.0° to 95.0° (0.11 PFDS), 57.3° (3.5 KH-570), and 57.0° (2.5 TMCS). The surface with controllable wettability was obtained by optimizing the amount of modifier. The removal rate of 17α-ethinyl estradiol (EE2) was significantly increased within a certain range of wettability. The WCA ranges of 1:1 AgI/BiVO 4 composites modified by PFDS, KH-570, and TMCS were 68.3–75.8°, 42.0–52.3°, and 42.0–54.7°, respectively, and the removal rate of EE2 was significantly higher. The photocatalytic activity was the best when the WCAs were 75.8° (0.05 PFDS), 51.0° (2.0 KH-570), and 48.1° (1.3 TMCS), and the removal rates of EE2 in 20 min under visible light were 90.0%, 92.9%, and 99.4%, respectively. These values were significantly better than those of unmodified 1:1 AgI/BiVO 4 composite (74.7%) and pristine BiVO 4 (8.4%). The results show that appropriate wettability improves photocatalytic activity. WCA diagram of 1:1 AgI/BiVO 4 composites before and after modification (a) and photocatalytic degradation of EE2 by composite photocatalysts before and after modification under visible light irradiation (b). Image 1 • AgI/BiVO 4 composites with controllable wettability were successfully prepared. • The composites have excellent photocatalytic properties under visible light irradiation. • The catalytic performance of the modified composites has been greatly improved when in the suitable wettability range. [ABSTRACT FROM AUTHOR]