Fe、Cr共掺杂TiO_2纳米球的制备

以钛酸丁酯、九水硝酸铁、九水硝酸铬、为原料,采用改进新工艺溶胶-凝胶法制备Fe、Cr共掺杂的TiO_2纳米球光催化材料,且用超声波热处理调控其微结构,通过溶胶-凝胶法加超声波辅助热处理合成了铁铬共掺杂纳米球平均粒径大小约为17.836μm,比普通煅烧处理具有较高的结晶度且平均粒径小。采用X射线衍射仪、激光粒度仪、热重天平、扫描电子显微镜等对样品的形貌和晶型进行了表征。结果表明Fe-Cr-TiO_2纳米球均为高度结晶的锐钛矿晶型,Fe、Cr共掺杂对TiO_2显著的提高其自身的结晶程度,热重分析结果显示制备得到的TiO_2锐钛矿晶体转变为金红石相晶体的相转变温度明显降低。此次研究为改进TiO_2光催化光水解性能提供新的方法,促进太阳能光催化光水解材料的发展。     

Enhancement in the photocatalytic activity of Bi2Ti2O7 nanopowders synthesised via Pechini vs Co-Precipitation method

Bi₂Ti₂O₇ nanopowders were synthesised via two different methods i.e. Pechini (P) and Co-Precipitation (C) method by annealing at 550 °C for 16 h. The effect of synthesis technique on photocatalytic activity of Bi₂Ti₂O₇ nanopowders was extensively studied. Formation of pure Bi₂Ti₂O₇ pyrochlore phase was observed in both samples. Various crystallographic parameters obtained by reitveld analysis of X-Ray Diffraction (XRD) spectra of both samples infer the formation of a highly loose crystallographic structure in P sample. The smaller crystallite size of P sample correlates with the observed blue shift in the Raman spectra, furthermore decreasing the particle size in P sample. P sample exhibits higher specific surface area, mean pore diameter and total pore volume which is inferred by Brunauer-Emmett-Teller (BET) analysis. Higher photocatalytic activity of P sample can be attributed to the formation of distorted crystallographic structure and higher specific surface area.     

Platinum/zinc oxide nanoparticles: Enhanced photocatalysts degrade malachite green dye under visible light conditions

Zinc oxide nanoparticles (ZnO) were prepared via a sol–gel method, and a photo-assisted deposition method was used to prepare platinum on zinc oxide nanoparticles (Pt/ZnO). Several techniques were used to characterize these enhanced photocatalysts: XRD, TEM, UV–vis spectra, PL spectra, XPS, and BET surface area analysis. As-prepared samples’ photocatalytic performances were studied via degradation of malachite green dye under various visible-light-only irradiation scenarios. Results demonstrated the following: platinum (Pt) was well dispersed on and in ZnO's surfaces and pores; as such, Pt/ZnO had less surface area than pure ZnO due to pore blockage; however, advantages gained from enhanced electron-hole separation and decreased band gap width more than made up for this negative effect; moreover, Pt/ZnO prepared with 0.3 wt% Pt exhibited the lowest band gap and the highest photocatalytic activity of the various samples with a solids loading of 0.8 g/l; finally, such samples were recyclable, i.e., photocatalytic performance remained stable even after five uses.     

采用TiO_2光催化剂的空气清新纺织品

介绍了一种新型的空气清新剂TiO2 光催化剂的反应原理 ,并探讨了其在纺织领域中的应用和存在问题 ,提出了解决方法等     

Phase Characterizations and Photocatalytic Applications of CuO-K2M04013 Composites

A series of CuO-K₂Mo₄O₁₃composite materials have been prepared by mixing appropriates quantities,in solid state,of CuO and pure K₂Mo₄O₁₃ according to the molar ratios CuO/K₂Mo₄O₁₃ = 0.05,0.1,0.2,0.5,and 1.The prepared samples were characterized using techniques such as X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,differential thermal analysis（DTA）,nitrogen adsorption measurements,and UV spectroscopy.According to XRD results,the phase composition of the CuO-K₂Mo₄O₁₃ systems has significantly changed by increasing the molar ratio CuO/K₂Mo₄O₁₃ where new phases,identified as K₂Mo₃O₁₀ and CuMoO₄,have been detected.The formation of these new phases has been tracked through FT-IR and DTA measurements.The nitrogen adsorption-desorption measurements also reveal a change in the pore type of me studied materials due to the presence of these new phases.The photocatalytic activities of K₂Mo₄O₁₃ and CuO-K₂Mo₄O₁₃ composites were studied by means of monitoring the ability of these materials to the degradation,under UV irradiation,of methyl red in liquid media.It was found that the phase composition of the used samples significantly controls their photocatalytic activities.     

Plasmonic semiconductor: A tunable non-metal photocatalyst

Doped semiconductor, a newly discovered plasmonic nanomaterial, has attracted tremendous interest due to its tunable properties. In the field of photocatalysis, the perfect combination of metal-like and semiconductor properties makes it the replacement and supplement of metal plasmonic nanomaterials. This new plasmonic photocatalysis offers high conversion efficiencies and wide optical absorption range with low fabrication costs. This article reviews the recent developments and achievements by which the localized surface plasmon resonance (LSPR) in non-metal plasmonic nanomaterial for photocatalytic applications, including pure non-metal plasmonic photocatalysts and various enhancement strategies such as doping, co-catalyst, heterojunction, LSPR coupling and upconversion luminescence enhancement. It broadens the horizons for plasmonics in the study of photocatalysis and even in energy-related applications.     

Recent progress on MXenes and MOFs hybrids: Structure,synthetic strategies and catalytic water splitting

The 2D MXenes (carbides, nitrides, carbonitrides) is an emerging class of atomic layered nanomaterials that calls for intensive investigation. The tunable structures, large-surface to volume ratio, high electrical conductivity, rich surface chemistries, hydrophilicity and large redox active sites are some vital features which makes MXenes the suitable catalyst for water splitting. However, MXenes suffers from the key limitation of agglomeration, reduced long term stability and recyclability. The coupling of MXenes with metal organic frameworks (MOFs) is an effective strategy owing to the high surface area, porosity, diverse functionalities, pore-confinement effect, and tunable coordination space of MOFs provides a preferential environment for hosting MXene to prevent its agglomeration. The review aims to showcase the synergistic effects of MXenes and MOFs hybrids by exploiting the inherent features of both frameworks for water splitting application. Herein, the electronic, structural and optical properties of MXenes and MOFs frameworks are elaborated. A detailed discussion on the synthetic strategies of MXenes and MOFs hybrids explains the importance of etching technique. Lastly, variant future challenges have been highlighted to better understand the present research and progression of MXenes and MOFs hybrids.     

Implementation of ZnSnO3 nanosheets and their RE (Er,Eu, and Pr) materials: Enhanced photocatalytic activity

ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr materials were synthesized by a hydrothermal method, these active materials characterized by XRD, Raman, DRS-UV, FT-IR, BET surface areas and Scanning electron microscopy studies. The ZnSnO₃ nanosheets meta-stable form was confirmed by XRD. Here, addressing to the pure and doped materials functional groups were evaluated by FT-IR spectroscopy. ZnSnO₃, ZnSnO₃@Er, ZnSnO₃@Eu, and ZnSnO₃@Pr rotational vibrations frequency modes were predicted by the Raman spectroscopy. Our results are marvelously, the obtained bandgap energies at 3.5 eV for pure sample and ZnSnO₃@Er, ZnSnO₃@Eu and ZnSnO₃@Pr energies at 3.06 eV, 3.04 eV and 3.02 eV. The synthesized pure samples get a sheet-like morphology and doped for RE metals than morphology was changing for nanocubes. We assess for all samples that were focused on photocatalytic dye degradation for Methylene blue dye; hence, we are discussing these approaches, ZnSnO₃@Pr/Methylene blue sample was a great improvement and high decolorization efficiency compared with ZnSnO₃@Er, ZnSnO₃@Eu nanocubes. The ZnSnO₃@Pr sample surface area was investigated by BET analysis. In addition, we are testing the phenol degradation with wastewater. The ZnSnO₃@Er, ZnSnO₃@Eu catalysts were determined to the less efficiency when comparing to the ZnSnO₃@Pr material. The ZnSnO₃@Pr material results have more efficiency and a very good recyclable stability nature.     

Visible-Light-Induced Photocatalytic Inactivation of Bacteria by Composite Photocatalysts of Palladium Oxide and Nitrogen-Doped Titanium Oxide

Composite photocatalysts of palladium oxide and nitrogen-doped titanium oxide (PdO/TiON) were synthesized by a sol–gel process, as convenient forms of nanopowder or immobilized powder on nanofiber. The PdO/TiON catalysts were tested for visible-light-activated photocatalysis using different bacterial indicators, including gram-negative cells of Escherichia coli and Pseudomonas aeruginosa, and gram-positive cells of Staphylococcus aureus. Disinfection data indicated that PdO/TiON composite photocatalysts have a much better photocatalytic activity than either palladium-doped (PdO/TiO₂) or nitrogen-doped titanium oxide (TiON) under visible-light illumination. The roles of Pd and N were discussed in terms of the production and separation of the charge carriers under visible-light illumination. The photocatalytic activity was thus dependent on dopants and light intensity. Microscopic characterization demonstrated that visible-light photocatalysis on PdO/TiON caused drastic damage on the bacteria cell wall and the cell membrane.