scholarly journals Preparation of N-TiO2/SiO2 composites by solvothermal method and their photocatalytic properties

Author(s):  
Chunli Wu ◽  
Xiaohao Dong ◽  
Lan Wang ◽  
Lei Zhang ◽  
Xiaotong Liu

Abstract In order to improve the visible light catalytic activity of titanium dioxide (TiO2) and ensure its long-term stability on the surface of concrete, an N-TiO2/SiO2 composite was prepared using tetrabutyl titanate, nitric acid, and modified SiO2 nanospheres as the precursors by a solvothermal method. The effect of nitric acid on the phase composition, morphology and photoelectric properties of the synthesized photocatalytic composites was systematically studied by various characterization methods. The results show that the optimum nitric acid/butyl titanate volume ratio is 1/6. The nitrogen-doped TiO2 nanoparticles were uniformly dispersed on the surface of spherical SiO2 with a diameter of 200 nm. The degradation rate of simulated pollutants (RhB) with pH 5 and 7 exceeded 95% within 30 minutes and the catalytic effect remained excellent after five repetitions without much weakening. The excellent visible photocatalytic performance can be attributed to the doping of N replacing part of the oxygen atoms in TiO2, forming the energy level of N 2p at the O 2p energy level and reducing the TiO2 energy band gap to 2.99 eV. At the same time, the better dispersion of N-TiO2/SiO2 prepared by this new synthesis method also plays an important role in the improvement of visible light photocatalytic activity.

2010 ◽  
Vol 434-435 ◽  
pp. 860-862
Author(s):  
Xiao Quan Zhang ◽  
Xiao Hui Wang ◽  
Tie Yu Sun ◽  
Ai Li Cui ◽  
Long Tu Li

A solvothermal method to synthesize barium titanate nanoparticles is employed. In this method many raw materials such as oleic acid, surfactant, sodium hydroxide, alkali barium acetate, alcohol, tetrabutyl titanate are used. When the samples are collected, oleic acid which has mush an account will cover the whole particles. To make the samples cleaner, nitric acid is used to transition oleic acid to elaidic acid which is lighter than water then it will float up to be removed. In the progress to wash off the oleic acid the particles were found to reunite unusually: bigger and cubic particles are formed and the shape seems like single crystal but they are reunitions indeed, we used HTEM to prove this. It means self–assembling might happen through the progress, the spontaneous polarization orient, polarity of molecules will affect this progess.


2021 ◽  
Author(s):  
Hanghang Zhou ◽  
Lan Wang ◽  
Hang Shi ◽  
Huan Zhang ◽  
Yue Wang ◽  
...  

Combining different semiconductor materials with diverse geometric structures and energy level configurations is an effective strategy for constructing high-activity heterostructure photocatalyst. Using the solvothermal method, 1D TiO2 nanobelts were uniformly...


Applied Nano ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 148-161
Author(s):  
Katerina Govatsi ◽  
Aspasia Antonelou ◽  
Labrini Sygellou ◽  
Stylianos G. Neophytides ◽  
Spyros N. Yannopoulos

The rational synthesis of semiconducting materials with enhanced photoelectrocatalytic efficiency under visible light illumination is a long-standing issue. ZnO has been systematically explored in this field, as it offers the feasibility to grow a wide range of nanocrystal morphology; however, its wide band gap precludes visible light absorption. We report on a novel method for the controlled growth of semiconductor heterostructures and, in particular, core/sheath ZnO/MoS2 nanowire arrays and the evaluation of their photoelectrochemical efficiency in oxygen evolution reaction. ZnO nanowire arrays, with a narrow distribution of nanowire diameters, were grown on FTO substrates by chemical bath deposition. Layers of Mo metal at various thicknesses were sputtered on the nanowire surface, and the Mo layers were sulfurized at low temperature, providing in a controlled way few layers of MoS2, in the range from one to three monolayers. The heterostructures were characterized by electron microscopy (SEM, TEM) and spectroscopy (XPS, Raman, PL). The photoelectrochemical properties of the heterostructures were found to depend on the thickness of the pre-deposited Mo film, exhibiting maximum efficiency for moderate values of Mo film thickness. Long-term stability, in relation to similar heterostructures in the literature, has been observed.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 529
Author(s):  
Adilah Sirivallop ◽  
Salvador Escobedo ◽  
Thanita Areerob ◽  
Hugo de Lasa ◽  
Siriluk Chiarakorn

This research studies the photocatalytic conversion of methanol (25–90 µmol/L range) as a volatile organic compound (VOC) surrogate into CO2, using a N/Ag/TiO2 photocatalyst under visible light irradiation in a Photo-CREC Air unit. The N/Ag/TiO2 mesh supported photocatalyst is prepared via the solvothermal method. While the bare-TiO2 is inactive under visible light, the N/Ag/TiO2 2 wt.% loaded stainless-steel woven mesh displays 35% quantum yields, with 80% absorbed photons and 60% methanol conversion in a 110 min irradiation period. Results obtained are assigned to silver surface plasmon resonance, silver and nitrogen species synergistic impacts on band gap, and their influence on particle agglomerate size and semiconductor acidity. The determined quantum yields under visible light in a Photo-CREC Air unit, are the highest reported in the technical literature, that these authors are aware of, with this opening unique opportunity for the use of visible light for the purification of air from VOC contaminants.


RSC Advances ◽  
2014 ◽  
Vol 4 (88) ◽  
pp. 47615-47624 ◽  
Author(s):  
Ping Li ◽  
Chunbo Liu ◽  
Guoling Wu ◽  
Yang Heng ◽  
Shuang Lin ◽  
...  

In this paper, Fe-doped SrTiO3 (FSTO) photocatalysts were successfully prepared via a facile solvothermal method, and their photocatalytic activities for degrading tetracycline (TC) under visible light irradiation were examined.


2017 ◽  
Vol 5 (20) ◽  
pp. 3718-3727 ◽  
Author(s):  
Saibo Chen ◽  
Hao Nan ◽  
Xuan Zhang ◽  
Yuting Yan ◽  
Zhou Zhou ◽  
...  

Bi2WO6 functionalized reduced oxide nanocomposites were prepared by a one-step solvothermal method and their photoelectrochemical performance was greatly improved.


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