- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photocatalytic Degradation of Methylene Blue over TiO2 Pretreated with Varying Concentrations of NaOH
摘要： In this paper, different NaOH concentrations (2, 5, 10, and 15 M) were used to treat {001}TiO2. The effect of NaOH on the crystal structure, morphology, optical properties, light raw electronic-hole recombination, and degradation performance of {001}TiO2 on methylene blue were studied. The results demonstrate that rutile TiO2 appeared when the NaOH concentration was as high as 10 M, showing much better photolytic performance than others. As the concentration of sodium hydroxide increases, the morphology changes accordingly. The specific surface area increases and the optical electronic-hole recombination rate decreases. Radical scavenging tests showed that hydroxyl radical and hole are very important in photocatalysis.
关键词： NaOH concentration,radical scavenging,{001}TiO2,methylene blue,photocatalysis
更新于2025-11-14 17:03:37
-
Loading of alkaline hydroxide nanoparticles on the surface of Fe2O3 for the promotion of photocatalytic activity
摘要： This study focused on surface modification of iron oxide (Fe2O3) by loading alkaline oxide nanoparticles to investigate the effect of surface interactions on photocatalytic activity of this material. Fe2O3 was loaded by NaOH, KOH, and CsOH, with 0.05, 0.1, 0.4, and 1 wt% by impregnation method. The photocatalytic evaluation was carried out in a gas phase for degradation of Iso-Propyl alcohol (IPA) to acetone. The prepared samples were characterized by X-ray diffraction, UV-Visible diffuse reflectance spectroscopy, and scanning electron microscopy SEM. The photocatalytic evaluation resulted the photoactivity of Fe2O3 increases to an optimum extent by loading of alkaline hydroxides on the surface. The enhancement of photoactivity of Fe2O3 after loading can be attributed to the surface chemical reactions and transfer of photogenerated electrons from the conduction band of Fe2O3 to alkaline nanoparticles. Also, multi-electron oxygen reduction is another way supposed to facilitate the photocatalytic reaction.
关键词： CsOH,Photocatalysis,NaOH,Photodegradation,Impregnation,KOH,Fe2O3
更新于2025-09-23 15:22:29
-
Facile synthesis of NaOH-promoted Pt/TiO2 catalysts for toluene oxidation under visible light irradiation
摘要： NaOH-promoted Pt/TiO2 catalysts are successfully prepared by a facile impregnation method assisted by NaOH and tested for the toluene oxidation reaction under visible light irradiation. Keeping molar ratio of Pt:Na =1:8, the 0.1Pt-Na/TiO2 catalyst (0.1 mol% Pt) shows excellent catalytic performance with more than 60% of toluene conversion at 45 oC and achieving total toluene removal at 280 oC, which is significantly better than 0.1Pt/TiO2 catalyst. The structures and properties of catalysts are characterized by XRD, SEM, N2 adsorption, XPS and UV-vis spectra. The positively charged Pt species stabilized by NaOH are the most active sites for photo-thermal catalyzing toluene oxidation. The influence of Pt loading and the effect of supports (active TiO2 and inert Al2O3) are also discussed.
关键词： photo-thermal catalysis,toluene oxidation,TiO2,NaOH,Pt
更新于2025-09-23 15:21:21
-
Synthesis of Urchin-like and Yolk-shell TiO <sub/>2</sub> microspheres with enhanced photocatalytic properties
摘要： The novel urchin-like and yolk-shell titania microspheres (henceforth called UYTMs) with nanowires/microspheres hierarchical structures were successfully synthesized by a synthetic sol-gel and hydrothermal method without using any template. Uniform TiO2 microspheres were firstly prepared by the sol-gel method, and the great monodispersed properties was delicately regulated by using the surfactant of KCl, aniline and a proper amount of water. The urchin-like yolk-shell morphology was further achieved by a NaOH-assisted hydrothermal process, and the diameter and shell thickness of the UYTMs were highly controlled by the concentration of NaOH. The detailed morphology, chemical composition and crystallinity of the UYTMs were systematically characterized by several techniques, and the underlying formation mechanisms was attentively discussed as well. The photodegradation of methylthionine chloride experiments indicated the UYTMs showed much better photocatalytic activity than that of commercial P25. This is mainly because the UYTMs exhibited much more reactive sites, higher adsorption ability and tuned optical absorption behavior owing to their large specific surface area, hierarchical structures and the special hollow yolk-shell structure.
关键词： Titania,NaOH-assisted hydrothermal synthesis,Photocatalytic activity,Yolk-shell,Urchin-like microspheres
更新于2025-09-10 09:29:36
-
Porous graphitic carbon nitride with controllable nitrogen vacancies: As promising catalyst for enhanced degradation of pollutant under visible light
摘要： Carbon nitride (CN) materials are considered as promising photocatalysts due to the advantages of easy availability and visible light absorption. However, wide band gap and high recombination rates of electron-hole pairs of conventional CN materials remain the “bottleneck” of the photocatalysts. Therefore, it is necessary to develop an efficient strategy to narrow band gap of CN and accelerate its charge transfer. In addition, the introduction of nitrogen (N) vacancies is an efficient strategy to narrow band gap and reduce recombination rates of electron-hole pairs. Herein, a novel triazole ring-based graphite carbon nitride (g-C3N5) is developed by one step pathway of NaOH-assisted condensation of triazole rings for the first time. It is found that NaOH can control N vacancies and band gap of g-C3Nx. Meanwhile, the N vacancies of g-C3Nx gradually increase with the increasing concentration of NaOH in the range of 0.005-0.1 g, suppressing the recombination of photogenerated electron-hole pairs. The proposed g-C3Nx exhibits outstanding photocatalytical and photoelectrochemical performance. Therefore, the study highlights the significance of N vacancies in enhancing the photocatalytical and photoelectrochemical performance of promising g-C3N5.
关键词： outstanding photocatalytical and photoelectrochemical performance,g-C3N5,NaOH-treated condensation of triazole rings,controllable N vacancies
更新于2025-09-09 09:28:46