One-dimensional Ag3PO4/TiO2 heterostructure with enhanced photocatalytic activity for the degradation of 4-nitrophenol

RSC Advances ◽  
2015 ◽  
Vol 5 (38) ◽  
pp. 29693-29697 ◽  
Author(s):  
Mingyi Zhang ◽  
Lu Li ◽  
Xitian Zhang

A one-dimensional Ag3PO4/TiO2 heterostructure exhibits enhanced photocatalytic activity due to the good visible light absorption capability and excellent charge separation characteristics of the formed heterojunction.

RSC Advances ◽  
2020 ◽  
Vol 10 (60) ◽  
pp. 36930-36940 ◽  
Author(s):  
Petri M. Leukkunen ◽  
Ekta Rani ◽  
Assa Aravindh Sasikala Devi ◽  
Harishchandra Singh ◽  
Graham King ◽  
...  

Robust photocatalytic activity of Ni–Ag–RTiO2 is attributed to the improved visible light absorption and effective charge separation due to intimate contact between Ni and RTiO2via Ag, as evidenced by Ti3+ in Ti 2p XPS and energy dispersive mapping.


RSC Advances ◽  
2014 ◽  
Vol 4 (26) ◽  
pp. 13469-13476 ◽  
Author(s):  
Farheen N. Sayed ◽  
R. Sasikala ◽  
O. D. Jayakumar ◽  
R. Rao ◽  
C. A. Betty ◽  
...  

Graphene nanoplatelets and Ti3+ enhance the photocatalytic activity of TiO2 due to extended visible light absorption and improved charge separation.


Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>


RSC Advances ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 4935-4941
Author(s):  
Riza Ariyani Nur Khasanah ◽  
Hui-Ching Lin ◽  
Hsiang-Yun Ho ◽  
Yen-Ping Peng ◽  
Tsong-Shin Lim ◽  
...  

Cu2O/TNA/Ti photoanode showed spectral response outperformed Cu2O/Ti and Cu2O/FTO photocathodes. Cu2O/TNA/Ti showed better spectral response than that of TNA/Ti, ascribed to UV-visible light absorption of Cu2O, not to charge separation enhancement.


Author(s):  
Mehala Kunnamareddy ◽  
Ranjith Rajendran ◽  
Megala Sivagnanam ◽  
Ramesh Rajendran ◽  
Barathi Diravidamani

AbstractIn this work, Nickel (Ni) and sulfur (S) codoped TiO2 nanoparticles were prepared by a sol-gel technique. The as-prepared catalyst was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), FT-Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra (DRS) for investigating crystal structure, crystal phase, particle size and bandgap energy of these samples. The photocatalytic performances of all the prepared catalysts have been investigated for the degradation of methylene blue (MB) under visible light irradiation. It was noticed that Ni-S codoped TiO2(Ni-S/TiO2) nanoparticles exhibited much higher photocatalytic activity compared with pure, Ni and S doped TiO2 due to higher visible light absorption and probable decrease in the recombination of photo-generated charges. It was decided that the great visible light absorption was created for codoped TiO2 by the formation of impurity energy states near both the edges of the collection, which works as trapping sites for both the photogenerated charges to decrease the recombination process.


2015 ◽  
Vol 1806 ◽  
pp. 19-24 ◽  
Author(s):  
John E. Mathis

ABSTRACTThere is great interest in improving TiO2’s photocatalytic activity in the visible portion of electromagnetic spectrum. Recent work has shown that co-doping mesoporous TiO2 microparticles with a transition metal and nitrogen, hereby designated as (M,N) TiO2, significantly increases its visible light absorption. However, the hydrothermal method used to produce the microparticles creates a wide distribution in the size of the microparticles, which could affect the absorption properties. Recently, it has become possible to produce monodisperse, mesoporous TiO2 microparticles with engineered sizes using a hybrid sol-gel/hydrothermal technique. Further, it has also been shown that the size of monodisperse TiO2 microparticles affects the the photocatalytic activity.This study investigated whether using mondodisperse (M,N) TiO2 microparticles would further increase visible-light absorption for (M,N)TiO2. The first-row transition metals chosen for this study - Mn, Fe, Co, Ni, and Cu – have been characterized in the earlier (M,N) TiO2 UV-vis study, which was used as a baseline. The doping levels of the transition metals samples were set at the 2.5 percent level previously shown to be optimum for photocatalytic activity.


2020 ◽  
Vol 7 (12) ◽  
pp. 2343-2351
Author(s):  
Ran Wang ◽  
Guoan Lin ◽  
Xiaoxiang Xu

La/Zr co-doping preserves visible light absorption of SrTaO2N, prohibits the formation of defects, improves surface hydrophilicity and charge separation conditions, all of which contribute to an enhanced photocatalytic activity for water reduction.


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