Key Words:Irradiation;Bismuth compounds - Energy gap - Heterojunctions - High resolution transmission electron microscopy - Nanocrystals - Photocatalysts - Purification - Scanning electron microscopy - Semiconductor quantum dots - Titanium dioxide - Transmission electron microscopy - Water treatment plants - X ray diffraction - X ray photoelectron spectroscopy;Carbon quantum dots - Diffuse reflectance spectroscopy - Hybrid photocatalysts - Hydrothermal methods - Photocatalytic activities - Photocatalytic performance - Synthesis temperatures - Water purification
Abstract:A series of novel binary TiO<inf>2</inf>/BiOX (X = Cl, Br, I) and ternary TiO<inf>2</inf>/CQDs/BiOBr hybrid photocatalysts were prepared through a facile hydrothermal method. TiO<inf>2</inf>/BiOX heterostructures were fabricated by varying the halogen ions. The photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV–Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Among the binary TiO<inf>2</inf>/BiOX, TiO<inf>2</inf>/BiOBr showed the most preferable photocatalytic activities due to suitable band gap alignment and photo stability, reaching almost 80% MO degradation during 180 min irradiation under simulated sunlight. Moreover, the effects of synthesis temperature, Ti/Bi ratio on the composition and structure were investigated, the results indicated TiO<inf>2</inf>/BiOBr with Bi/Ti = 10% prepared at 120 °C possessed the best photocatalytic performance. Carbon quantum dots were introduced to accelerate electrons transfer at interface or prevent charges recombination on the surface, resulting a much better photocatalytic performance for TiO<inf>2</inf>/CQDs/BiOBr hybrid photocatalysts.<br/> © 2018 Elsevier Ltd
Volume:264
Translation or Not:no